On Jun 17, 8:30*pm, Searcher7 wrote:
On Jun 17, 10:17*am, Jim Wilkins wrote:
...
...And determine if it is plausible to expect to be able to pass
3/4" through the spindle under any circumstances.
...
Darren Harris

Sure it is. Use a chuck.
jsw

Any circumstances with a collet attached. :-)
Darren Harris

Depending on how attached you are to your financial circumstances; :-
(
http://www.hardinge.com/usr/pdf/collet/B123_Sjogren.pdf
http://www.ecolletchucks.com/BISON/B...ET-CHOICES.htm

Personally I'd buy the $2500 Grizzly that takes 5C, or an old Logan or
South Bend (which I did).

jsw

On 2010-06-17, Searcher7 wrote:
On Jun 17, 7:43*am, Jim Wilkins wrote:

[ ... ]

If you can pass the rod stock through the spindle you can machine a
part on the end with access to its entire length. Otherwise you have
to plan how to machine the area clamped within the collet or chuck
jaws in a second operation with less centering accuracy, or waste some
material, or hold it between centers. The difference is mostly
convenience and forethought.

[ ... ]

Yes, I just need to figure out the differences between MT3 and 3C
collets. And determine if it is plausible to expect to be able to pass
3/4" through the spindle under any circumstances.

Yes and no!

1) No -- with 3C collets.

2) No -- *no* diameter with MT3 collets.

3) Yes -- with a chuck on the spindle.

4) Yes -- with a 5C collet chuck on the spindle

5) Yes -- with an ER collet chuck which mounts to the spindle nose
instead of via the internal Morse taper of the spindle.

I may not bother getting collets that have more than a 3/4" capacity
for my lathe.

Unless you can mount them outside the spindle (e.g. the external
5C collet chuck, or an ER chuck which mounts properly to the spindle
nose. This is an argument for having both the 3C collets for smaller
work, and the external 5C collet chuck or the ER chuck if you can
find/make one to fit your spindle nose.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Jun 17, 10:21*pm, "DoN. Nichols" wrote:
On 2010-06-17, Searcher7 wrote:

On Jun 17, 7:43 am, Jim Wilkins wrote:

* * * * [ ... ]

If you can pass the rod stock through the spindle you can machine a
part on the end with access to its entire length. Otherwise you have
to plan how to machine the area clamped within the collet or chuck
jaws in a second operation with less centering accuracy, or waste some
material, or hold it between centers. The difference is mostly
convenience and forethought.

* * * * [ ... ]

Yes, I just need to figure out the differences between MT3 and 3C
collets. And determine if it is plausible to expect to be able to pass
3/4" through the spindle under any circumstances.

* * * * Yes and no!

1) * * *No -- with 3C collets.

2) * * *No -- *no* diameter with MT3 collets.

3) * * *Yes -- with a chuck on the spindle.

4) * * *Yes -- with a 5C collet chuck on the spindle

5) * * *Yes -- with an ER collet chuck which mounts to the spindle nose
* * * * instead of via the internal Morse taper of the spindle.

I may not bother getting collets that have more than a 3/4" capacity
for my lathe.

* * * * Unless you can mount them outside the spindle (e.g. the external
5C collet chuck, or an ER chuck which mounts properly to the spindle
nose. *This is an argument for having both the 3C collets for smaller
work, and the external 5C collet chuck or the ER chuck if you can
find/make one to fit your spindle nose.

Yes. I'm on my way. :-)

Thanks a lot.

Darren Harris
Staten Island, New York.

On 2010-06-18, Searcher7 wrote:
On Jun 17, 10:15 pm, "DoN. Nichols" wrote:
On 2010-06-17, Searcher7 wrote:

On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
On 2010-06-16, Searcher7 wrote:

On Jun 14, 10:57 pm, "DoN. Nichols" wrote:
On 2010-06-14, Searcher7 wrote:

[ ... ]

Oh yes -- also the WW series (watchmaker's) collet set for a
couple of my smaller machines will hold up to 1/4" short grip, but the
next size down will pass through as before.

Now since my spindle bore is .787, wouldn't a collet set that fits my
lathe spindle *and* allows diameters up to 3/4" be better?

How are you going to get that? Not with a collet with a drawbar
or drawtube which has to pass through the spindle -- that's for sure.

MT3 collets are obviously out. A shame because I was about to jump on
this set: 110544744384

Note that they are described as *milling* collets -- for holding
end mills, not as work holding collets, which is what you are looking
for.

And the largest capacity for 3C collets 1/2".(With an occasional 9/16"
floating around). But you're saying that I can't pass *any* stock
through the spindle with a 3C collet mounted?

No. I'm saying that you can't pass *any* stock through the
spindle with *MT3* collets.

For 3C collets, the draw tube will pass the same maximum size
that the collet will -- just one size under 1/2" for the 3C collets,
IIRC.

The key to look for in the descriptions of the systems is
drawbar (solid, external threads) vs drawtube (hollow, internal threads,
and can pass work through the spindle.)

However -- a collet chuck which will hold 5C collets and which
will mount on the spindle's nose the same way the chuck does will do
that -- at the cost of some of the distance between the spindle nose and
the tailstock center.

I assume this wouldn't be an issue if I'm passing the stock through
the spindle anyway.

It is a loss of rigidity as you extend more distant from the
spindle nose.

A while back when we were discussing milling on the lathe it was
decided that 5C collets would go no where near the spindle, until I
got that 5C collet chuck that is held in a chuck. So in view of
everything perhaps I should put this back on my shopping list:
http://littlemachineshop.com/product...ProductID=3047

The collet chuck if you want the benefit of being able to pass
through the spindle (while held by collets) workpieces between 0.4375"
and 0.748" (the limit set by your spindle -- which appears to be 19 mm
-- and *might* actually pass 3/4" (19.05mm). Check it with some 3/4"
drill rod.

Of course, for workpieces up to 1", you could chuck them in the
collet chuck at least as deep as from the nose of the collet to the
spindle nose adaptor plate -- a little longer than the collet.

I already have 5 collets and a 5C collet chuck would mean I wouldn't
need any more collets.

You really want the 3C collets and drawtube assembly for smaller
diameter workpieces. It is more true than a collet chuck because it
centers on the internal taper of the spindle.

The only disadvantage is that unlike 3C I wouldn't be able to use 5C
in the spindle directly.

Right -- more stick-out from the spindle nose, and loss of
rigidity. And *perhaps* a little more runout -- especially without the
adjust-tru style collet chuck.

(Or I can just skip collets altogether and concentrate on practicing
centering with that 4 jaw independent chuck I'm getting). :-)

That is a good plan for the short term. It will lead you to
appreciate a 3-jaw chuck and a collet for speed. :-)

But wait. Wouldn't the option of passing stock through the spindle
tend to negate the disadvantages of that "poor man's" collet chuck I
have that would hang out over the lathe bed?
http://s290.photobucket.com/albums/l...lletChuck3.jpg

No -- you don't have enough jaw depth to really grip that firmly
enough. You would have a serious loss of rigidity. And you have to
remove it from the chuck to loosen the collet (IIRC), so you would have
to tune your 4-jaw chuck back to center after each workpiece change.

And I would think that through the spindle would help make centering a
little easier.(Or perhaps I'm tired and not thinking clearly).

Not with that collet chuck -- you have to unchuck it every time
you change the workpiece stock projection.

Nevertheless, I can still use the collet stop with 5C collets for
repeatability.

Yes -- hmmm *maybe* with the collet chuck you are considering
you don't have much room behind the collet before you hit the backplate.

The ER collets will handle up to the 3/4" (or larger depending
on the size) but most of the chucks for holding those have a Morse
taper, which would preclude *anything* going through the spindle other
than the Morse taper and its drawbar.

My Emco-Maier Compact-5/CNC has a flat nose with a 40 mm OD for
a register and a MT-2 internal taper. It has a holder for one of the
smaller ER collet sets (ER-25 I think) and will pass through the collet
chuck stock as big as the spindle will pass -- roughly 1/2" -- proably
actually 13mm or so, since it is Austrian made. Something like this
could be made to fit your lathe (if you can't find one already) and this
would be shorter than the standard external 5C collet chuck.

If it existed I probably would have come across it, which means it
would probably be a project for someone with experience.

O.K. Or you after you *get* more experience. Your really need
to assemble your mill and start using it and the lathe, just to get a
feel for what I am talking about.

I'm trying to figure out what the differences are between 3MT and 3
collets.
http://littlemachineshop.com/product...ProductID=1991
http://littlemachineshop.com/product...ProductID=1615

Quite simple -- the MT3 collets are really made for tool
holding, not work holding (some mills have a Morse taper spindle,
including old small Bridgeports).

But -- they fit directly in the spindle's taper, so there is
only one interface to introduce possible runout.

The 5C collets will pass through the spindle all but the largest
size -- assuming a hollow drawtube, not a solid one bored and threaded
on the end to fit the collets. :-)

They need an adaptor -- the spindle's Morse taper to the
collet's nose taper, with a key pin to keep them from spinning while you
are trying to tighten the handwheel. This means that there is the
possible lack of concentricity between the OD of the Morse taper part
and the ID of the collet nose taper. And -- there are two surfaces
where a bit of grit or similar will introduce temporary runout error.

There is an exception to this -- Hardinge lathes have a spindle
which *directly* accepts the 3C or 5C collet (depending on lathe size).

Since my lathe will *directly* accept 3C collets, perhaps I should get
several anyway.

Actually -- it does not *directly* accept the 3C collets. It
needs a nosepiece adaptor, which is shown in the quoted URL below.

http://littlemachineshop.com/product...ProductID=2240

Note that the collet closer sets *include* this, so you don't
have to buy it separately.

[ ... ]

If accuracy is not very important then turning between centers and
using a chuck would probably be better than going through all that
trouble, correct?

Turning between centers *will* be the most accurate if done
right.

A 3-jaw chuck is quick to use, and the slight runout only
matters under two conditions:

1) You're making something from stock already the desired largest
finish diameter, so there is nothing to skim off to gain
concentricity. (Most stock is a little oversized, especially
hot rolled steel, to give you this ability.)

2) You're making something where you have to machine one end, then
turn it around and machine the other end, and it is important
that the two ends be concentric.

Number 2 will be an important issue for me for some projects.

And for that -- turn between centers for anything small enough
on the end for a dog and capable of being center-drilled on both ends.

A 4-jaw chuck can be tuned to make things as concentric as you
have the ability to measure and the patience to tune it right.

That's why I have to concentrate on getting that chuck.(Though I
supposed there would be no good reason to create an adapter that will
allow it to be mounted to my rotary table).

Have you yet put your 3-jaw chuck on the lathe and *done*
anything with it? Really -- get some experience playing with it.

As an amateur inventor I'm more into the innovative projects, so I
have the luxury of deciding the size of the stock and finished work,
so I'll be unlikely to need emergency collets if I already have the
basic sizes on hand in quality collets.

Yes -- unless you find yourself making something to fit
something else built to the Metric system -- to adapt something which
you can get cheaply instead of having to make the whole thing from
scratch. Note my recent purchase of a 5mm 5C collet for something which
I need to make parts for.

I'll keep my fingers crossed and hope this issue doesn't come up
often. :-)

This is one reason to have an emergency collet on hand -- so you
can make one to fit strange needs.

[ ... ]

I'm assuming this wouldn't work with the MT3. correct?

The MT3 has an internal thread, and requires a solid drawbar,
usually tightened with a wrench instead of a handwheel -- but you could
use a handwheel if you so desired. I, personally, would not use MT3
collets for many things -- though having a standard Morse taper spindle
on the dividing head would make finding centers easier. :-)

This is what I'll also use my lathe tailstock's MT2 dead center for.
Not just for my lathe tailstock. (I'll need a good way to center the
rotary table).

O.K. Or you could sweep out the ID of the Morse taper in the
rotary table just as well.

[ ... ]

With the mill/drill, spin indexer and hor./vert. collet fixture the
collet blocks are now in the "what do I do with..." category.

They may fit your mill better than the spin indexer. And both
the spin indexer and the collet blocks use the same collets, which is a
help.

Fit my mill?

Put a round workpiece in the collet in the collet block, and
clamp the collet block horizontally in the milling vise to mill a flat on
the side of the workpiece -- or to mill a keyway in the round piece
depending on your needs. The combination of the vise (especially
without the rotary base installed) and the horizontal collet block will
be lower than either the spin indexer or an index head, so more room for
tooling between the spindle nose and the workpiece.

[ ... ]

Note, BTW, that while most end mill holders are a precise
sliding fit on the mill shank, there are some made which are
intentionally undersized. You heat the holder, drop in the end mill,
and it is there forever once they reach the same temperature. :-)

That doesn't sound like something I'd ever want to do.

It is the sort of thing done for high speed production work on
powerful CNC machines. I don't think that you will need that. :-)

[ ... ]

I might indeed have paid that much for a Lyndex set -- in spite
of being retired with a fixed income.

But I have been known to buy sets *new* from MSC.

Ok. If that one guy had not bid I would have gotten them for under
$50. :-)

"If wishes were horses ... " :-)

FWIW -- looking in MSC's web page, I find a set of Lyndex
collets 1-16 - 1-1/8 by 16ths for $371.93 new. NuLine is $230.68, and
"Value" is $145.72.

And if you stick with Lyndex, and go to steps of 64ths, you are
talking about $1,942.46. :-)

And to believe I was so close to filling out the other half of my
import collets to 64ths. (A complete Lyndex collect is not even on the
radar). :-)

Nor mine -- unless I win a lottery, and since I don't buy the
tickets, this is unlikely. :-0

My set is an import set, at a sale price from one of their
flyers some years ago. So far, they have been good enough for me. :-)

Perhaps the piece of mind which comes form owning something of quality
will make the extra money spent worth it. :-)

For me -- the important thing is whether they do what I need.

[ ... ]

Note that many of those don't work well for thicker workpieces.
The cutting forces can tilt the workpiece out of the grip of one end.
And the clamps on the top get in the way of some cuts -- so you have to
cut part way, install a second clamp, remove the first, and continue.
Also, that kind of setup is easier with a mill table which has two or
three T-slots, not the single T-slot which your machine has.

Ok. So this is still me best option?
http://littlemachineshop.com/product...ProductID=1144

It is only *one* option. You should have a good milling vise of
the right size for your machine, and the clamp set, and work-stops to
bolt directly to the T-slot to keep the workpiece from slipping under
heavy cuts.

This was the original plan: http://littlemachineshop.com/product...ProductID=3489

This is a good start -- including a Kurt style milling vise,
which has the benefit that as it tightens it pulls the moving jaw (and
thus the workpiece) down towards the bed of the vise -- reducing the
needed pounding with a plastic or lead-filled leather mallet.

But after reading I decided a screw vise would be better.

A "screw vise"? You mean a toolmaker's vise with a screw at a
45 degree angle? (Often actually called a "screwless vise".) Those
maker more sense on smaller machines, (such as my baby Emco-Maier C5
mill, which uses ER-25 collets), or on surface grinders where they are
held down by the magnetic chuck.

It does cover R8 collets. (But no wavy parallels). :-)

Note that the parallel set included goes up to 1-5/8", while the
jaws of the vise ar only 1.04" deep, so only 5 of the 10 parallels will
do you any good -- at least until you get a bigger mill and vise.

I have the set of end mills -- and they work well when I don't
need larger end mills (I've got up to 1-1/2" plus much larger horizontal
milling cutters.)

I would have to go down and check to see whether they all have
shanks which would fit the set of collets. You might need to add a
5/16" and a 7/16" collet to the sset.

The center drill set will be useful in the lathe too.

The vise mounting kit is nice to have -- though it could be made
up from the clamping kit. Better to have the separate vise mounting kit
so parts don't get lost. :-)

And the T-slot cleaner is nice to have.

Have you *measured* the width of the top of the slots in your
machine? Make sure that it fits.

It definitely would fit. (My mill/drill is on it's compatibility
list).

O.K.

[ ... ]

Well ... you probably don't need the adjust-tru.

Unless I use the chuck on the lathe also, correct? (I'm just trying to
determine if I should still consider getting that $159 used 4" 3 jaw
with Adjust-Tru).

Consider whether you really need the Adjust-Tru feature.

Well, with all this talk of collets... :-)

Yes -- but you are the one who is focused on them to the extent
of selling a new import set to buy the used Lyndex set.

Work with the machines and learn what you need to do your
projects. You can't learn it all just by reading.

[ ... ]

So -- you are making it from scratch? The chuck with a Morse
taper back is very likely to be hardened, so skimming off the taper is
unlikely. And you are likely to have something on the order of 1/2" of
length to deal with.

And how are you going to reduce the taper diameter with milling
operations? This is a lathe task -- or a cylindrical grinder task.

Is there a grinding option for a mill/drill?

Not for a mill-drill -- but for larger mills there is a grinder
which is part boring head. But these are for grinding cylindrical
bearing bores, not for grinding tapers. I don't know how to grind a
taper on any mill other than a high-end CNC mill.

Also -- note that a tiny difference in diameter produces a large
difference in seating depth. Dust off your trig and calculate from the
angle. (It is approximately 6 degrees given your approximation of
0.600"/foot on a Morse taper.)

The ideas are formulating, and I love a challenge. :-) (But there
would seem to be a lot of hogging to do at the beginning).

Yes -- a lot of hogging on something which is hardened. Note
that when grinding you take perhaps at most 0.005" per pass.

[ ... ]

Nevertheless, I guess that like my lathe, a 5" chuck would fit the
rotary table, but it would still be considered too big.

Mostly -- it is too big only in terms of leaving a skirt to
clamp it down by. If you are going to drill through the chuck body for
bolts to reach T-nuts, it is a different matter. (And 4-jaw chucks,
which is what you would need with the 4 slots, tend to have a lot of
hollow casting, and the back plate attaches only near the hub. You'll
commonly see four bolts through the chuck body between the jaws and in
close to the center.

Oh. Why do so many prefer 3 jaw chucks on their rotary tables?

Because they are quicker to use, are usually *accurate* *enough*
for 99% of the work, and tuning a 4-jaw is a pain, and tuning a 4-jaw on
a rotary table where you have to keep turning the table to check your
progress. (A lot easier on a lathe.)

Nevertheless, a 4" 4 jaw independent chuck would be as close to ideal
as possible between my lathe and rotary table.

I disagree -- but you will learn -- if you ever get around to
actually *using* what you are getting.

So a 4" it is.
(Though I wouldn't be able to hold those 4" disks with it).

With outside jaws, you likely could. With two-piece jaws, you
could make top jaws which reach out far enough for the purpose while
keeping the master jaws entirely within the body of the chuck.

Ok. Then this shouldn't be a problem.

The main trick is to be careful (on the lathe) that the jaws
don't stick out far enough to hit the ways of the lathe bed -- or the
arms of the carriage if they stick out towards the headstock end.

[ ... ]

Really -- make a backplate which has a sliding fit on a
cylindrical extension of the Morse taper so the plate is held
concentric, but not forced clear of the table's surface.

Ok. That is what I'll do.

Good!

[ ... ]

Yes, I know. I already have the 3" 3 jaw chuck that came with the
lathe.

So -- make a plate which fits the rotary table with a nose to
match the lathe's nose, so you can mount the chuck on the plate, then
the plate on the rotary table.

I'm assuming a single plate that would fit both the lathe and the
rotary table.

No -- you are making a plate which fits on the rotary table
which has a projection which duplicates the nose piece of the lathe, so
the chuck could be attached to that plate just as it is attached to the
lathe's spindle. Thus -- you can swap it between the two at will (as
long as you can get to the bolts, which I believe come form the back of
the chuck).

Ok. So I'll be basically duplicating the lathe's nose piece.

Yes. And this means that you can mount *any* desired work
holding device on either the lathe spindle or the rotary table -- as
long as it is not large enough in diameter to hide the mounting bolts
from plate to rotary table T-slots.

Plan on getting the right size counterbore so you can have the
screws which mount the chuck within the thickness of the adaptor plate.
(Which also defines the needed thickness of the adaptor plate probably
twice the height of the screw head.)

[ ... ]

Ok. A 6-1/4" face plate will be made. (Out of cast iron I assume).

6-1/4"? That is about the size of the dog driver plate for my
12" lathe. The dogs tend to not extend out as far as the maximum
workpiece diameter. Remember that the dog can form an off-center
weight, causing the lathe to dance around the table at certain speeds.

Now a faceplate for bolting workpieces to is a different matter,
and *that* can be fairly large. And when you bolt on an off-center
workpiece, you will want to also bolt on a counterweight (scrap steel)
to keep the balance somewhat more reasonable.

Yes. BTW. 6-1/4" is the standard size face plate for this mini lathe.

For a face plate -- not for a dog driving plate.

[ ... ]

O.K. I did not know about the Lyndex set when I asked that
question. But bear in mind that I have been using an import set for
years, and it has been satisfactory so far. Granted, I got it from MSC,
which probably has higher quality import sets than some. :-)

I won't need "precision" parts yet, outside of certain things we were
talking about making for my machines. But at least when the time comes
I won't have to worry about buying a whole new set of *quality*
collets.

O.K.

Or take a block of aluminum, mill dovetails to fit your
quick-change toolpost, bore it to fit a air driven die grinder (some
have cylindrical handles, which are easier to use for this), slit one
side and add clamp bolts to tighten it onto the die grinder, and you
have a quick and dirty toolpost grinder. (And *dirty* applies to *all*
toolpost grinders. :-)

Yeah, but can I get TIRs within .0001. :-)

You have three places for eccentricity to come from:

1) The internal taper of the spindle nose. Check that with
nothing installed with a sensitive runout gauge.

2) The relationship between the external and internal taper of
the collet adaptor.

3) The relationship between the external taper end of the
collet itself and the bore of the collet.

BTW -- note that the collet adaptor nosepiece itself says:

'The 3C collet bore is concentric with the 3 Morse taper within
0.0002".'

so no matter how precise your 3C collets, you'll never be sure of
getting 0.0001" TIR.

I suspect the same accuracy on my 5C collet nosepiece on my
12x24" Clausing, exclusive of errors in the spindle or the collets
themselves.

And I don't expect the collet chuck you are looking at to be
anywhere near this accuracy.

BTW Looking at the Lyndex page, I find this:

http://www.lyndex.com/news_products.asp?id=150

which is the tool for shrink fitting end mill holders to end mills, and
it apparently can also be used for removing broken tools from a
shrink-fit holder.

I can't seem to find a spec on TIR for these collets.

If there is eccentricity in (1) and (2) above, you can minimize
the error from them by rotating the adaptor until you get a minimum
runout. Once you have this right, mark the collet adaptor so it will
always go in the same orientation.

This will have to be one of my later projects after I get my feet wet.

Just pointing out that the most perfect collets in the world are
still at the mercy of their mounting. If you can't make the mounting
true *first* there is no point to grinding the collets true.

Yes. The collet grinding may be too much so early in my learning
curve.

Starting with checking the TIR on your collet nosepiece and if
necessary, grinding the taper concentric -- if you *insist* on being so
anal about concentricity.

Good luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Jun 18, 5:44 pm, "DoN. Nichols" wrote:
On 2010-06-18, Searcher7 wrote:

On Jun 17, 10:15 pm, "DoN. Nichols" wrote:
On 2010-06-17, Searcher7 wrote:

On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
On 2010-06-16, Searcher7 wrote:

On Jun 14, 10:57 pm, "DoN. Nichols" wrote:
On 2010-06-14, Searcher7 wrote:

[ ... ]

Oh yes -- also the WW series (watchmaker's) collet set for a
couple of my smaller machines will hold up to 1/4" short grip, but the
next size down will pass through as before.

Now since my spindle bore is .787, wouldn't a collet set that fits my
lathe spindle *and* allows diameters up to 3/4" be better?

How are you going to get that? Not with a collet with a drawbar
or drawtube which has to pass through the spindle -- that's for sure.

MT3 collets are obviously out. A shame because I was about to jump on
this set: 110544744384

Note that they are described as *milling* collets -- for holding
end mills, not as work holding collets, which is what you are looking
for.

Ok. I guess if I were to use them in the lathe they wouldn't be better
than the MT3 end mills I have.

And the largest capacity for 3C collets 1/2".(With an occasional 9/16"
floating around). But you're saying that I can't pass *any* stock
through the spindle with a 3C collet mounted?

No. I'm saying that you can't pass *any* stock through the
spindle with *MT3* collets.

For 3C collets, the draw tube will pass the same maximum size
that the collet will -- just one size under 1/2" for the 3C collets,
IIRC.

Ok. That's what I thought.

The key to look for in the descriptions of the systems is
drawbar (solid, external threads) vs drawtube (hollow, internal threads,
and can pass work through the spindle.)

However -- a collet chuck which will hold 5C collets and which
will mount on the spindle's nose the same way the chuck does will do
that -- at the cost of some of the distance between the spindle nose and
the tailstock center.

I assume this wouldn't be an issue if I'm passing the stock through
the spindle anyway.

It is a loss of rigidity as you extend more distant from the
spindle nose.

Yes. I understand the rigidity part. I was thinking about that the
room the 5C collet chuck taking up would not be an issue in and of
itself when I'm passing stock through the spindle.

A while back when we were discussing milling on the lathe it was
decided that 5C collets would go no where near the spindle, until I
got that 5C collet chuck that is held in a chuck. So in view of
everything perhaps I should put this back on my shopping list:
http://littlemachineshop.com/product...ProductID=3047

The collet chuck if you want the benefit of being able to pass
through the spindle (while held by collets) workpieces between 0.4375"
and 0.748" (the limit set by your spindle -- which appears to be 19 mm
-- and *might* actually pass 3/4" (19.05mm). Check it with some 3/4"
drill rod.

..787" is the size of my spindle bore, which is why I was hoping to
pass through as large as .750".

Of course, for workpieces up to 1", you could chuck them in the
collet chuck at least as deep as from the nose of the collet to the
spindle nose adaptor plate -- a little longer than the collet.

I already have 5 collets and a 5C collet chuck would mean I wouldn't
need any more collets.

You really want the 3C collets and drawtube assembly for smaller
diameter workpieces. It is more true than a collet chuck because it
centers on the internal taper of the spindle.

3C it is. (1/16", 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16").

But It doesn't look as though I'll find these from Hardinge, Lyndex,
or Royal.

(BTW. I noticed that eBay sellers like to throw in the name southbend,
even when the collets are of a different brand. As in "for South Bend
lathes" or "for Bridgeport milling machines". As if these collets
would only fit those spcific machines. I assume this is supposed to be
a marketing angle).

The only disadvantage is that unlike 3C I wouldn't be able to use 5C
in the spindle directly.

Right -- more stick-out from the spindle nose, and loss of
rigidity. And *perhaps* a little more runout -- especially without the
adjust-tru style collet chuck.

So it seems that if I get the 5C collet chuck it should at least be an
Adjust -Tru. (Which would run a couple hundred dollars more).

But I even though it would be a more advanced project, I haven't given
up on this kit idea. http://www.sc-c.com/metallathe/MLA21.html

(Or I can just skip collets altogether and concentrate on practicing
centering with that 4 jaw independent chuck I'm getting). :-)

That is a good plan for the short term. It will lead you to
appreciate a 3-jaw chuck and a collet for speed. :-)

But wait. Wouldn't the option of passing stock through the spindle
tend to negate the disadvantages of that "poor man's" collet chuck I
have that would hang out over the lathe bed?
http://s290.photobucket.com/albums/l.../Tools/?action...

No -- you don't have enough jaw depth to really grip that firmly
enough. You would have a serious loss of rigidity. And you have to
remove it from the chuck to loosen the collet (IIRC), so you would have
to tune your 4-jaw chuck back to center after each workpiece change.

Well, I'll be doing mostly one-offs.(With a few two-offs mixed
in). :-)

And I would think that through the spindle would help make centering a
little easier.(Or perhaps I'm tired and not thinking clearly).

Not with that collet chuck -- you have to unchuck it every time
you change the workpiece stock projection.

Nevertheless, I can still use the collet stop with 5C collets for
repeatability.

Yes -- hmmm *maybe* with the collet chuck you are considering
you don't have much room behind the collet before you hit the backplate.

Well, since the collets stops are cheap there is only one way to find
out. :-)

The ER collets will handle up to the 3/4" (or larger depending
on the size) but most of the chucks for holding those have a Morse
taper, which would preclude *anything* going through the spindle other
than the Morse taper and its drawbar.

My Emco-Maier Compact-5/CNC has a flat nose with a 40 mm OD for
a register and a MT-2 internal taper. It has a holder for one of the
smaller ER collet sets (ER-25 I think) and will pass through the collet
chuck stock as big as the spindle will pass -- roughly 1/2" -- proably
actually 13mm or so, since it is Austrian made. Something like this
could be made to fit your lathe (if you can't find one already) and this
would be shorter than the standard external 5C collet chuck.

If it existed I probably would have come across it, which means it
would probably be a project for someone with experience.

O.K. Or you after you *get* more experience. Your really need
to assemble your mill and start using it and the lathe, just to get a
feel for what I am talking about.

Yeah. I've been bouncing back and forth between the lathe and mill/
drill because I keep running into walls.(I still have to get that tool
post milled down before I mount it with the modified compund to my
lathe).

I'm trying to figure out what the differences are between 3MT and 3
collets.
http://littlemachineshop.com/product...ProductID=1991
http://littlemachineshop.com/product...ProductID=1615

Quite simple -- the MT3 collets are really made for tool
holding, not work holding (some mills have a Morse taper spindle,
including old small Bridgeports).

But -- they fit directly in the spindle's taper, so there is
only one interface to introduce possible runout.

The 5C collets will pass through the spindle all but the largest
size -- assuming a hollow drawtube, not a solid one bored and threaded
on the end to fit the collets. :-)

They need an adaptor -- the spindle's Morse taper to the
collet's nose taper, with a key pin to keep them from spinning while you
are trying to tighten the handwheel. This means that there is the
possible lack of concentricity between the OD of the Morse taper part
and the ID of the collet nose taper. And -- there are two surfaces
where a bit of grit or similar will introduce temporary runout error.

There is an exception to this -- Hardinge lathes have a spindle
which *directly* accepts the 3C or 5C collet (depending on lathe size).

Since my lathe will *directly* accept 3C collets, perhaps I should get
several anyway.

Actually -- it does not *directly* accept the 3C collets. It
needs a nosepiece adaptor, which is shown in the quoted URL below.

http://littlemachineshop.com/product...ProductID=2240

Ok. I meant no collet chuck is needed. :-)

Note that the collet closer sets *include* this, so you don't
have to buy it separately.

Yes. But I wonder if these on eBay are a better deal than the two LMS
link below: 130371901373 390079264989

http://littlemachineshop.com/product...ProductID=1991
http://littlemachineshop.com/product...ProductID=2374

If accuracy is not very important then turning between centers and
using a chuck would probably be better than going through all that
trouble, correct?

Turning between centers *will* be the most accurate if done
right.

A 3-jaw chuck is quick to use, and the slight runout only
matters under two conditions:

1) You're making something from stock already the desired largest
finish diameter, so there is nothing to skim off to gain
concentricity. (Most stock is a little oversized, especially
hot rolled steel, to give you this ability.)

2) You're making something where you have to machine one end, then
turn it around and machine the other end, and it is important
that the two ends be concentric.

Number 2 will be an important issue for me for some projects.

And for that -- turn between centers for anything small enough
on the end for a dog and capable of being center-drilled on both ends.

Will do.

A 4-jaw chuck can be tuned to make things as concentric as you
have the ability to measure and the patience to tune it right.

That's why I have to concentrate on getting that chuck.(Though I
supposed there would be no good reason to create an adapter that will
allow it to be mounted to my rotary table).

Have you yet put your 3-jaw chuck on the lathe and *done*
anything with it? Really -- get some experience playing with it.

It is already on the lathe, since that is the supplied chuck.(The
original toolpost which I didn't bother getting tools for is still on
the lathe also.

As an amateur inventor I'm more into the innovative projects, so I
have the luxury of deciding the size of the stock and finished work,
so I'll be unlikely to need emergency collets if I already have the
basic sizes on hand in quality collets.

Yes -- unless you find yourself making something to fit
something else built to the Metric system -- to adapt something which
you can get cheaply instead of having to make the whole thing from
scratch. Note my recent purchase of a 5mm 5C collet for something which
I need to make parts for.

I'll keep my fingers crossed and hope this issue doesn't come up
often. :-)

This is one reason to have an emergency collet on hand -- so you
can make one to fit strange needs.

[ ... ]

I'm assuming this wouldn't work with the MT3. correct?

The MT3 has an internal thread, and requires a solid drawbar,
usually tightened with a wrench instead of a handwheel -- but you could
use a handwheel if you so desired. I, personally, would not use MT3
collets for many things -- though having a standard Morse taper spindle
on the dividing head would make finding centers easier. :-)

This is what I'll also use my lathe tailstock's MT2 dead center for.
Not just for my lathe tailstock. (I'll need a good way to center the
rotary table).

O.K. Or you could sweep out the ID of the Morse taper in the
rotary table just as well.

"Sweep out?"

With the mill/drill, spin indexer and hor./vert. collet fixture the
collet blocks are now in the "what do I do with..." category.

They may fit your mill better than the spin indexer. And both
the spin indexer and the collet blocks use the same collets, which is a
help.

Fit my mill?

Put a round workpiece in the collet in the collet block, and
clamp the collet block horizontally in the milling vise to mill a flat on
the side of the workpiece -- or to mill a keyway in the round piece
depending on your needs. The combination of the vise (especially
without the rotary base installed) and the horizontal collet block will
be lower than either the spin indexer or an index head, so more room for
tooling between the spindle nose and the workpiece.

Ok. That's what you meant.

Note, BTW, that while most end mill holders are a precise
sliding fit on the mill shank, there are some made which are
intentionally undersized. You heat the holder, drop in the end mill,
and it is there forever once they reach the same temperature. :-)

That doesn't sound like something I'd ever want to do.

It is the sort of thing done for high speed production work on
powerful CNC machines. I don't think that you will need that. :-)

[ ... ]

I might indeed have paid that much for a Lyndex set -- in spite
of being retired with a fixed income.

But I have been known to buy sets *new* from MSC.

Ok. If that one guy had not bid I would have gotten them for under
$50. :-)

"If wishes were horses ... " :-)

I'd own the Kentucky Derby... :-)

FWIW -- looking in MSC's web page, I find a set of Lyndex
collets 1-16 - 1-1/8 by 16ths for $371.93 new. NuLine is $230.68, and
"Value" is $145.72.

And if you stick with Lyndex, and go to steps of 64ths, you are
talking about $1,942.46. :-)

And to believe I was so close to filling out the other half of my
import collets to 64ths. (A complete Lyndex collect is not even on the
radar). :-)

Nor mine -- unless I win a lottery, and since I don't buy the
tickets, this is unlikely. :-0

My set is an import set, at a sale price from one of their
flyers some years ago. So far, they have been good enough for me. :-)

Perhaps the piece of mind which comes form owning something of quality
will make the extra money spent worth it. :-)

For me -- the important thing is whether they do what I need.

[ ... ]

Note that many of those don't work well for thicker workpieces.
The cutting forces can tilt the workpiece out of the grip of one end.
And the clamps on the top get in the way of some cuts -- so you have to
cut part way, install a second clamp, remove the first, and continue.
Also, that kind of setup is easier with a mill table which has two or
three T-slots, not the single T-slot which your machine has.

Ok. So this is still me best option?
http://littlemachineshop.com/product...ProductID=1144

It is only *one* option. You should have a good milling vise of
the right size for your machine, and the clamp set, and work-stops to
bolt directly to the T-slot to keep the workpiece from slipping under
heavy cuts.

This was the original plan:http://littlemachineshop.com/product...ProductID=3489

This is a good start -- including a Kurt style milling vise,
which has the benefit that as it tightens it pulls the moving jaw (and
thus the workpiece) down towards the bed of the vise -- reducing the
needed pounding with a plastic or lead-filled leather mallet.

But after reading I decided a screw vise would be better.

A "screw vise"? You mean a toolmaker's vise with a screw at a
45 degree angle? (Often actually called a "screwless vise".) Those
maker more sense on smaller machines, (such as my baby Emco-Maier C5
mill, which uses ER-25 collets), or on surface grinders where they are
held down by the magnetic chuck.

Yeah. Screwless. :-)

It does cover R8 collets. (But no wavy parallels). :-)

Note that the parallel set included goes up to 1-5/8", while the
jaws of the vise ar only 1.04" deep, so only 5 of the 10 parallels will
do you any good -- at least until you get a bigger mill and vise.

Well, the screwless thwy sell allow use of all but one.
http://littlemachineshop.com/product...ProductID=2356

(I'm looking to get wavy and also adjustable parallels anyway).

I have the set of end mills -- and they work well when I don't
need larger end mills (I've got up to 1-1/2" plus much larger horizontal
milling cutters.)

I would have to go down and check to see whether they all have
shanks which would fit the set of collets. You might need to add a
5/16" and a 7/16" collet to the sset.

Though not Lyndex these are the best deal I've found. (On eBay):
130362779707

The center drill set will be useful in the lathe too.

I have two or three sets.

The vise mounting kit is nice to have -- though it could be made
up from the clamping kit. Better to have the separate vise mounting kit
so parts don't get lost. :-)

And the T-slot cleaner is nice to have.

Have you *measured* the width of the top of the slots in your
machine? Make sure that it fits.

It definitely would fit. (My mill/drill is on it's compatibility
list).

O.K.

[ ... ]

Well ... you probably don't need the adjust-tru.

Unless I use the chuck on the lathe also, correct? (I'm just trying to
determine if I should still consider getting that $159 used 4" 3 jaw
with Adjust-Tru).

Consider whether you really need the Adjust-Tru feature.

Well, with all this talk of collets... :-)

Yes -- but you are the one who is focused on them to the extent
of selling a new import set to buy the used Lyndex set.

Ijust don't wnat to have to stop several times though out a project to
get something I missed.

But my priority shoul dbe taking the spindle box of my mill/drill
apart to see what the problem is.(Since most of my initial projects
will have to be done on tthat machine).

Work with the machines and learn what you need to do your
projects. You can't learn it all just by reading.

[ ... ]

So -- you are making it from scratch? The chuck with a Morse
taper back is very likely to be hardened, so skimming off the taper is
unlikely. And you are likely to have something on the order of 1/2" of
length to deal with.

And how are you going to reduce the taper diameter with milling
operations? This is a lathe task -- or a cylindrical grinder task.

Is there a grinding option for a mill/drill?

Not for a mill-drill -- but for larger mills there is a grinder
which is part boring head. But these are for grinding cylindrical
bearing bores, not for grinding tapers. I don't know how to grind a
taper on any mill other than a high-end CNC mill.

Also -- note that a tiny difference in diameter produces a large
difference in seating depth. Dust off your trig and calculate from the
angle. (It is approximately 6 degrees given your approximation of
0.600"/foot on a Morse taper.)

The ideas are formulating, and I love a challenge. :-) (But there
would seem to be a lot of hogging to do at the beginning).

Yes -- a lot of hogging on something which is hardened. Note
that when grinding you take perhaps at most 0.005" per pass.

[ ... ]

Nevertheless, I guess that like my lathe, a 5" chuck would fit the
rotary table, but it would still be considered too big.

Mostly -- it is too big only in terms of leaving a skirt to
clamp it down by. If you are going to drill through the chuck body for
bolts to reach T-nuts, it is a different matter. (And 4-jaw chucks,
which is what you would need with the 4 slots, tend to have a lot of
hollow casting, and the back plate attaches only near the hub. You'll
commonly see four bolts through the chuck body between the jaws and in
close to the center.

Oh. Why do so many prefer 3 jaw chucks on their rotary tables?

Because they are quicker to use, are usually *accurate* *enough*
for 99% of the work, and tuning a 4-jaw is a pain, and tuning a 4-jaw on
a rotary table where you have to keep turning the table to check your
progress. (A lot easier on a lathe.)

Nevertheless, a 4" 4 jaw independent chuck would be as close to ideal
as possible between my lathe and rotary table.

I disagree -- but you will learn -- if you ever get around to
actually *using* what you are getting.

I meant as far as a chuck that I can use with both.(Since I already
have the 3" 3 jaw).

So a 4" it is.
(Though I wouldn't be able to hold those 4" disks with it).

With outside jaws, you likely could. With two-piece jaws, you
could make top jaws which reach out far enough for the purpose while
keeping the master jaws entirely within the body of the chuck.

Ok. Then this shouldn't be a problem.

The main trick is to be careful (on the lathe) that the jaws
don't stick out far enough to hit the ways of the lathe bed -- or the
arms of the carriage if they stick out towards the headstock end.

Yes. Also, perhaps this oone won't be the one to get, since 3.94" is
it's limit.
http://littlemachineshop.com/product...ProductID=1697

Really -- make a backplate which has a sliding fit on a
cylindrical extension of the Morse taper so the plate is held
concentric, but not forced clear of the table's surface.

Ok. That is what I'll do.

Good!

[ ... ]

Yes, I know. I already have the 3" 3 jaw chuck that came with the
lathe.

So -- make a plate which fits the rotary table with a nose to
match the lathe's nose, so you can mount the chuck on the plate, then
the plate on the rotary table.

I'm assuming a single plate that would fit both the lathe and the
rotary table.

No -- you are making a plate which fits on the rotary table
which has a projection which duplicates the nose piece of the lathe, so
the chuck could be attached to that plate just as it is attached to the
lathe's spindle. Thus -- you can swap it between the two at will (as
long as you can get to the bolts, which I believe come form the back of
the chuck).

Ok. So I'll be basically duplicating the lathe's nose piece.

Yes. And this means that you can mount *any* desired work
holding device on either the lathe spindle or the rotary table -- as
long as it is not large enough in diameter to hide the mounting bolts
from plate to rotary table T-slots.

Plan on getting the right size counterbore so you can have the
screws which mount the chuck within the thickness of the adaptor plate.
(Which also defines the needed thickness of the adaptor plate probably
twice the height of the screw head.)

I'll have to put "counterbore" in the MSc search to see what I get.

Ok. A 6-1/4" face plate will be made. (Out of cast iron I assume).

6-1/4"? That is about the size of the dog driver plate for my
12" lathe. The dogs tend to not extend out as far as the maximum
workpiece diameter. Remember that the dog can form an off-center
weight, causing the lathe to dance around the table at certain speeds.

Now a faceplate for bolting workpieces to is a different matter,
and *that* can be fairly large. And when you bolt on an off-center
workpiece, you will want to also bolt on a counterweight (scrap steel)
to keep the balance somewhat more reasonable.

Yes. BTW. 6-1/4" is the standard size face plate for this mini lathe.

For a face plate -- not for a dog driving plate.

You kind of lost me the first time you mentioned "Dog driving plate".
You mean a plate for the lathe dogs?

O.K. I did not know about the Lyndex set when I asked that
question. But bear in mind that I have been using an import set for
years, and it has been satisfactory so far. Granted, I got it from MSC,
which probably has higher quality import sets than some. :-)

I won't need "precision" parts yet, outside of certain things we were
talking about making for my machines. But at least when the time comes
I won't have to worry about buying a whole new set of *quality*
collets.

O.K.

Or take a block of aluminum, mill dovetails to fit your
quick-change toolpost, bore it to fit a air driven die grinder (some
have cylindrical handles, which are easier to use for this), slit one
side and add clamp bolts to tighten it onto the die grinder, and you
have a quick and dirty toolpost grinder. (And *dirty* applies to *all*
toolpost grinders. :-)

Yeah, but can I get TIRs within .0001. :-)

You have three places for eccentricity to come from:

1) The internal taper of the spindle nose. Check that with
nothing installed with a sensitive runout gauge.

2) The relationship between the external and internal taper of
the collet adaptor.

3) The relationship between the external taper end of the
collet itself and the bore of the collet.

BTW -- note that the collet adaptor nosepiece itself says:

'The 3C collet bore is concentric with the 3 Morse taper within
0.0002".'

so no matter how precise your 3C collets, you'll never be sure of
getting 0.0001" TIR.

I suspect the same accuracy on my 5C collet nosepiece on my
12x24" Clausing, exclusive of errors in the spindle or the collets
themselves.

And I don't expect the collet chuck you are looking at to be
anywhere near this accuracy.

I wonder how often concentric errors cancel each other out when
multiple surfaces are involved.

BTW Looking at the Lyndex page, I find this:

http://www.lyndex.com/news_products.asp?id=150

which is the tool for shrink fitting end mill holders to end mills, and
it apparently can also be used for removing broken tools from a
shrink-fit holder.

I can't seem to find a spec on TIR for these collets.

Lyndex collets? They are supposed to be within .0005. The import
collets are said to be "precision" when they are within that.(Going by
all the ads I've read).

If there is eccentricity in (1) and (2) above, you can minimize
the error from them by rotating the adaptor until you get a minimum
runout. Once you have this right, mark the collet adaptor so it will
always go in the same orientation.

This will have to be one of my later projects after I get my feet wet.

Just pointing out that the most perfect collets in the world are
still at the mercy of their mounting. If you can't make the mounting
true *first* there is no point to grinding the collets true.

Yes. The collet grinding may be too much so early in my learning
curve.

Starting with checking the TIR on your collet nosepiece and if
necessary, grinding the taper concentric -- if you *insist* on being so
anal about concentricity.

If those import collets don't sell on eBay, I'll check every one of
them. :-)

Thanks.

Darren Harris
Staten Island, New York.

On Jun 17, 7:43*am, Jim Wilkins wrote:
On Jun 17, 1:46*am, Searcher7 wrote:

On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
...

Now this is what's been bugging me. 3C will fit into my MT3 lathe
spindle, and MT3 collets will fit into my MT3 lathe spindle, correct

The 3Cs at LMS go as high as 1/2" and only allow a diameter as high
as .467 through the collet.(The site doesn't mention these specifics
for MT3 collets).

Now since my spindle bore is .787, wouldn't a collet set that fits my
lathe spindle *and* allows diameters up to 3/4" be better?
...

The closer tube eats into that 0.787". For my 5C set the tube OD is
1-3/8" (1.36"), the maximum ID is 1-1/16" (1.08"). The threads and the
wall thickness inside and outside them take up the rest.

I'm just a little confused by this. The last sentence in that
paragraph to be exact. The difference between the I.D. and O.D. of the
drawbtube is .28". Since it fits *around the collet, the drawtube
doesn't determine the maximum stock one can pass through the spindle,
correct?

You don't have to cover the full range with one type of collet. With
MT3 the only overhead is a threaded-rod drawbar and a nut and washer.
They don't cost you another spindle adapter if they fit already. You
could buy only the sizes above the range of 3C.
Here's a good example of available choices:http://www.finelinehair.com/home/9x2...lets_and_Adapt...

Since these are tool holding collets and don't allow stock in the
spindle I'll have to pass on them.

If you can pass the rod stock through the spindle you can machine a
part on the end with access to its entire length. Otherwise you have
to plan how to machine the area clamped within the collet or chuck
jaws in a second operation with less centering accuracy, or waste some
material, or hold it between centers. The difference is mostly
convenience and forethought.

?!?

It sounds like you're just saying that when passing the stock through
the spindle, a longer length of stock can be machined without un-
clamping. (Which is the same as saying to just use longer stock).

Thanks.

Darren Harris
Staten Island, New York.

On Jun 19, 11:25*am, Searcher7 wrote:
On Jun 17, 7:43*am, Jim Wilkins wrote:
On Jun 17, 1:46*am, Searcher7 wrote:
On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
...

Now this is what's been bugging me. 3C will fit into my MT3 lathe
spindle, and MT3 collets will fit into my MT3 lathe spindle, correct

The 3Cs at LMS go as high as 1/2" and only allow a diameter as high
as .467 through the collet.(The site doesn't mention these specifics
for MT3 collets).



If you can pass the rod stock through the spindle you can machine a
part on the end with access to its entire length. Otherwise you have
to plan how to machine the area clamped within the collet or chuck
jaws in a second operation with less centering accuracy, or waste some
material, or hold it between centers. The difference is mostly
convenience and forethought.

?!?

It sounds like you're just saying that when passing the stock through
the spindle, a longer length of stock can be machined without un-
clamping. (Which is the same as saying to just use longer stock).
Darren Harris

No. Deflection controls the maximum length you can have protruding
from the chuck or collet. The part inside the spindle is irrelevant.

What I intended to convey is that you can make a 1" part on the end of
a 36" rod and not waste any material. When you are done you still have
35" of good stock left (ignoring the cutoff bit). If you started with
a 2" blank, the half clamped in the chuck or collet would be wasted.
But you might have to if the full-length bar won't fit through the
spindle.

If the stock is too large to go through the spindle I cut off either a
6" piece to stick in the chuck or a 24" piece to turn with a steady
rest, even to make a 1" part. Then I still have a useful length left
over for the next part.

It may not be 6", rather the maximum length of that diameter that will
be stiff enough to cut. If I guess wrong I support it with the
tailstock center. When it's used up there is only one short scrap
piece, which may become a bushing.

What I DON'T want to do is turn my leftover stock into short useless
chunks cut off the ends of the parts I made.

^^^^ This is what passing the stock through the spindle is all about.

It also helps if you are making bicycle spokes or threading the ends
of tubing, long thin parts machined on both ends, but you can do them
between centers or with a steady rest if necessary. A long thin rod
protruding out the left end of the spindle will bend and whip around
unless you support it somehow.

You need more experience and less speculation, Aristotle. Use your 3
and 4 jaw chucks, they are the basic work holders, collets are a
luxury. I've brought them up to consider BEFORE buying a lathe. They
aren't worth a lot of fiddling to cobble on inaccurately afterwards.
In your case I would buy the 3C set and if needed, larger sizes in
MT3. You'll never find an elegant, complete and perfect solution to
everything (though 5C is close) and have to learn to adapt what you
have somehow, or bid the job out.

jsw

On Jun 19, 3:13*pm, Jim Wilkins wrote:
On Jun 19, 11:25*am, Searcher7 wrote:



On Jun 17, 7:43*am, Jim Wilkins wrote:
On Jun 17, 1:46*am, Searcher7 wrote:
On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
...

Now this is what's been bugging me. 3C will fit into my MT3 lathe
spindle, and MT3 collets will fit into my MT3 lathe spindle, correct

The 3Cs at LMS go as high as 1/2" and only allow a diameter as high
as .467 through the collet.(The site doesn't mention these specifics
for MT3 collets).

If you can pass the rod stock through the spindle you can machine a
part on the end with access to its entire length. Otherwise you have
to plan how to machine the area clamped within the collet or chuck
jaws in a second operation with less centering accuracy, or waste some
material, or hold it between centers. The difference is mostly
convenience and forethought.

?!?

It sounds like you're just saying that when passing the stock through
the spindle, a longer length of stock can be machined without un-
clamping. (Which is the same as saying to just use longer stock).
Darren Harris

No. Deflection controls the maximum length you can have protruding
from the chuck or collet. The part inside the spindle is irrelevant.

I thought that the distance between tailstock and headstock would
determine this. And I assume deflection is why steady rests were made.

What I intended to convey is that you can make a 1" part on the end of
a 36" rod and not waste any material. When you are done you still have
35" of good stock left (ignoring the cutoff bit). If you started with
a 2" blank, the half clamped in the chuck or collet would be wasted.
But you might have to if the full-length bar won't fit through the
spindle.

If the stock is too large to go through the spindle I cut off either a
6" piece to stick in the chuck or a 24" piece to turn with a steady
rest, even to make a 1" part. Then I still have a useful length left
over for the next part.

It may not be 6", rather the maximum length of that diameter that will
be stiff enough to cut. If I guess wrong I support it with the
tailstock center. When it's used up there is only one short scrap
piece, which may become a bushing.

What I DON'T want to do is turn my leftover stock into short useless
chunks cut off the ends of the parts I made.

^^^^ This is what passing the stock through the spindle is all about.

Yes. My determination is that with my lathe 9/16" would be the maximum
diameter I could pass through the spindle using 3C collets, because
that is the largest diameter these collets are made for.

Higher than that would require a 5C collet chuck for the 5C collets.

It also helps if you are making bicycle spokes or threading the ends
of tubing, long thin parts machined on both ends, but you can do them
between centers or with a steady rest if necessary. A long thin rod
protruding out the left end of the spindle will bend and whip around
unless you support it somehow.

Of course. But I have no projects like that on the horizon yet.

You need more experience and less speculation, Aristotle. Use your 3
and 4 jaw chucks, they are the basic work holders, collets are a
luxury. I've brought them up to consider BEFORE buying a lathe. They
aren't worth a lot of fiddling to cobble on inaccurately afterwards.
In your case I would buy the 3C set and if needed, larger sizes in
MT3. You'll never find an elegant, complete and perfect solution to
everything (though 5C is close) and have to learn to adapt what you
have somehow, or bid the job out.

MT3 collets use a drawbar, so they are not an option.

(Now to look into a lathe modification involving adding a 5C
spindle). :-)

Darren Harris
Staten Island, New York.

On 2010-06-19, Searcher7 wrote:
On Jun 18, 5:44 pm, "DoN. Nichols" wrote:
On 2010-06-18, Searcher7 wrote:


[ ... ]

MT3 collets are obviously out. A shame because I was about to jump on
this set: 110544744384

Note that they are described as *milling* collets -- for holding
end mills, not as work holding collets, which is what you are looking
for.

Ok. I guess if I were to use them in the lathe they wouldn't be better
than the MT3 end mills I have.

Other than you could change end mills in the collets. (Or do
you mean end mill *holders*?)

[ ... ]

However -- a collet chuck which will hold 5C collets and which
will mount on the spindle's nose the same way the chuck does will do
that -- at the cost of some of the distance between the spindle nose and
the tailstock center.

I assume this wouldn't be an issue if I'm passing the stock through
the spindle anyway.

It is a loss of rigidity as you extend more distant from the
spindle nose.

Yes. I understand the rigidity part. I was thinking about that the
room the 5C collet chuck taking up would not be an issue in and of
itself when I'm passing stock through the spindle.

Maybe or maybe not. It depends on how long an area of the
workpiece needs machining at a time.

Note, BTW, that the smaller the diameter of the workpiece, the
more likely that what sticks out the other end of the spindle will bend
and start to whip.

The higher the spindle speed, the more likely this is to happen,
too.

But -- you can do a nice job of constraining the workpiece with
some PVC pipe running from just past the outboard end of the spindle to
the free end of the workpiece which is not too much larger than the
workpiece. I have two tubes to handle this. One is a 1-1/2" PVC pipe
which fits in a cradle near the far end and is held down by bungee
cords. The other is a similar one, except that it has caps on both ends
which were bored on the lathe to be a precise fit on the OD of a much
smaller PVC pipe with that smaller PVC pipe glued into the caps. This
is used for things as small as 3/16" brass rod.

When it is spinning, the tip tries to move outward, and the
farther it gets from the center line, the more force. The PVC pipe
keeps it from getting far enough to be a problem.

So -- remember to leave room to the left of the spindle for the
long workpieces -- and provisions for supporting a tube to control the
whipping. If it ever *does* get to whipping, it can be very dangerous.
Also -- make sure that the lathe is firmly bolted down.

A while back when we were discussing milling on the lathe it was
decided that 5C collets would go no where near the spindle, until I
got that 5C collet chuck that is held in a chuck. So in view of
everything perhaps I should put this back on my shopping list:
http://littlemachineshop.com/product...ProductID=3047

The collet chuck if you want the benefit of being able to pass
through the spindle (while held by collets) workpieces between 0.4375"
and 0.748" (the limit set by your spindle -- which appears to be 19 mm
-- and *might* actually pass 3/4" (19.05mm). Check it with some 3/4"
drill rod.

.787" is the size of my spindle bore, which is why I was hoping to
pass through as large as .750".

O.K. You certainly should be able to get that through.

Of course, for workpieces up to 1", you could chuck them in the
collet chuck at least as deep as from the nose of the collet to the
spindle nose adaptor plate -- a little longer than the collet.

I already have 5 collets and a 5C collet chuck would mean I wouldn't
need any more collets.

You really want the 3C collets and drawtube assembly for smaller
diameter workpieces. It is more true than a collet chuck because it
centers on the internal taper of the spindle.

3C it is. (1/16", 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16").

O.K.

But It doesn't look as though I'll find these from Hardinge, Lyndex,
or Royal.

Not likely -- unless you find an old used set. Certainly
Hardinge made them in this size -- the 3C and 5C collets were
*originated* by them, which is why they are a direct fit in the spindle
of their machines.

(BTW. I noticed that eBay sellers like to throw in the name southbend,
even when the collets are of a different brand. As in "for South Bend
lathes" or "for Bridgeport milling machines". As if these collets
would only fit those spcific machines. I assume this is supposed to be
a marketing angle).

Yes -- someone is searching on the name of his machine (those
are the most popular serious machines in the hobby market), and they
find things which could be used in *some* machines by that maker. I hit
the same problem when searching on Clausing. Adding:

-"for Clausing"

to the search string will get some of those out of the listing. :-)

The only disadvantage is that unlike 3C I wouldn't be able to use 5C
in the spindle directly.

Right -- more stick-out from the spindle nose, and loss of
rigidity. And *perhaps* a little more runout -- especially without the
adjust-tru style collet chuck.

So it seems that if I get the 5C collet chuck it should at least be an
Adjust -Tru. (Which would run a couple hundred dollars more).

And -- it will stick out even more. The Adjust-tru takes up
perhaps an inch and a half between the backplate and the body. :-)

But I even though it would be a more advanced project, I haven't given
up on this kit idea. http://www.sc-c.com/metallathe/MLA21.html

Yes -- that is a good choice. And since the taper is machined
on the machine on which it is going to be used, as long as you make your
backplate fit the spindle nose precisely, you should have better
concentricity than on any pre-machined one you would buy.

He makes good things.

[ ... ]

But wait. Wouldn't the option of passing stock through the spindle
tend to negate the disadvantages of that "poor man's" collet chuck I
have that would hang out over the lathe bed?
http://s290.photobucket.com/albums/l.../Tools/?action...

No -- you don't have enough jaw depth to really grip that firmly
enough. You would have a serious loss of rigidity. And you have to
remove it from the chuck to loosen the collet (IIRC), so you would have
to tune your 4-jaw chuck back to center after each workpiece change.

Well, I'll be doing mostly one-offs.(With a few two-offs mixed
in). :-)

But you don't really have a feel for just how awkward to use
this would be. :-)

[ ... ]

Nevertheless, I can still use the collet stop with 5C collets for
repeatability.

Yes -- hmmm *maybe* with the collet chuck you are considering
you don't have much room behind the collet before you hit the backplate.

Well, since the collets stops are cheap there is only one way to find
out. :-)

O.K.

[ ... ]

If it existed I probably would have come across it, which means it
would probably be a project for someone with experience.

O.K. Or you after you *get* more experience. Your really need
to assemble your mill and start using it and the lathe, just to get a
feel for what I am talking about.

Yeah. I've been bouncing back and forth between the lathe and mill/
drill because I keep running into walls.(I still have to get that tool
post milled down before I mount it with the modified compund to my
lathe).

Which means that you want to get the mill working *first*. Or
-- learn to use the lathe with the toolpost which is supplied, so you
will appreciate the quick-change when you have it in service.

Oh yes -- do you have the dovetail cutters needed to clean up
the width of the dovetail?

[ ... ]

There is an exception to this -- Hardinge lathes have a spindle
which *directly* accepts the 3C or 5C collet (depending on lathe size).

Since my lathe will *directly* accept 3C collets, perhaps I should get
several anyway.

Actually -- it does not *directly* accept the 3C collets. It
needs a nosepiece adaptor, which is shown in the quoted URL below.

http://littlemachineshop.com/product...ProductID=2240

Ok. I meant no collet chuck is needed. :-)

O.K. That I will accept.

Note that the collet closer sets *include* this, so you don't
have to buy it separately.

Yes. But I wonder if these on eBay are a better deal than the two LMS
link below: 130371901373 390079264989

http://littlemachineshop.com/product...ProductID=1991
http://littlemachineshop.com/product...ProductID=2374

Well ... the collet set includes some extra sizes in the eBay
auction. The LMS set has seven, and the eBay auction has nine. It adds
a 1/16" on the small end, and a 9/16" (short grip) on the large end.
This might be a good one to go for. It does cost more but both sources
are about $10.00 per collet.

But note that the nosepiece adaptor is only *part* of what you
need to hold the collets -- and it is all that the eBay auction is
offering. Remember the drawtube which is part of the LMS kit. Since
the kit *includes* the collet adaptor, the fact that you can get another
adaptor for not too much still does not save you anything. And no clue
as to whether it is more or less accurate than the one which is part of
the kit.

[ ... ]

Have you yet put your 3-jaw chuck on the lathe and *done*
anything with it? Really -- get some experience playing with it.

It is already on the lathe, since that is the supplied chuck.(The
original toolpost which I didn't bother getting tools for is still on
the lathe also.

You might still be able to use the tools in the existing
toolpost -- or at least some of them. Gain some experience that way.

[ ... ]

The MT3 has an internal thread, and requires a solid drawbar,
usually tightened with a wrench instead of a handwheel -- but you could
use a handwheel if you so desired. I, personally, would not use MT3
collets for many things -- though having a standard Morse taper spindle
on the dividing head would make finding centers easier. :-)

This is what I'll also use my lathe tailstock's MT2 dead center for.
Not just for my lathe tailstock. (I'll need a good way to center the
rotary table).

O.K. Or you could sweep out the ID of the Morse taper in the
rotary table just as well.

"Sweep out?"

O.K. I was shifting the meaning of "finding centers" to getting
the table truly concentric under the spindle of the machine. You use an
indicator such as the Starrett "Last Word", or one of the better ones
from other makers, held in the spindle and feeling the ID of the taper.
You adjust the position so the indicator reading does not change as you
rotate the spindle through a full 360 degrees. If you have room for it,
a "Blake coax" indicator is more convenient, as the dial faces you
through the full rotation.

With the mill/drill, spin indexer and hor./vert. collet fixture the
collet blocks are now in the "what do I do with..." category.

They may fit your mill better than the spin indexer. And both
the spin indexer and the collet blocks use the same collets, which is a
help.

Fit my mill?

Put a round workpiece in the collet in the collet block, and
clamp the collet block horizontally in the milling vise to mill a flat on
the side of the workpiece -- or to mill a keyway in the round piece
depending on your needs. The combination of the vise (especially
without the rotary base installed) and the horizontal collet block will
be lower than either the spin indexer or an index head, so more room for
tooling between the spindle nose and the workpiece.

Ok. That's what you meant.

Yes. I used just such a setup in my horizontal mill yesterday,
using Woodruff Key cutters to make cuts down to a center bore to allow
punchings to exit from repeated use of the punch (which I had made) in a
motorized punch press. This is specifically for making a large number
of felt disks to cushion the travel of English Concertina buttons so
they don't click when they bottom.


[ ... ]

This was the original plan:http://littlemachineshop.com/product...ProductID=3489

This is a good start -- including a Kurt style milling vise,
which has the benefit that as it tightens it pulls the moving jaw (and
thus the workpiece) down towards the bed of the vise -- reducing the
needed pounding with a plastic or lead-filled leather mallet.

But after reading I decided a screw vise would be better.

A "screw vise"? You mean a toolmaker's vise with a screw at a
45 degree angle? (Often actually called a "screwless vise".) Those
maker more sense on smaller machines, (such as my baby Emco-Maier C5
mill, which uses ER-25 collets), or on surface grinders where they are
held down by the magnetic chuck.

Yeah. Screwless. :-)

It is more precise -- but much more awkward to use. Go back to
your LMS site and read:

http://littlemachineshop.com/info/vise_compare.php

The vise in the kit is what they call "Precision Milling Vise",
and is far better for most things done on the mill. That vise is
paterened on the "Kurt Anglock" and is *much* quicker to use. I have
three different sizes of these.

It does cover R8 collets. (But no wavy parallels). :-)

Note that the parallel set included goes up to 1-5/8", while the
jaws of the vise ar only 1.04" deep, so only 5 of the 10 parallels will
do you any good -- at least until you get a bigger mill and vise.

Well, the screwless thwy sell allow use of all but one.
http://littlemachineshop.com/product...ProductID=2356

It could be used in addition to the Kyrt style milling vise,
especially to hold things which need to be moved from the mill to
another tool. The "screwless" vise can be held crosswise in the Kurt,
the milling operation performed, and them moved to another tool, still
holding the workpiece. But get the Kurt style *first*.

(I'm looking to get wavy and also adjustable parallels anyway).

I don't have the wavy parallels so far, and don't feel the need.
As for the adjustable parallels -- they serve a different set of
functions -- mostly transferring measurements between awkward places and
micrometers -- either direction -- set the parallel to a micrometer and
then use it as a reference for positioning something -- or set the
parallel to fit a slot, and then measure the parallel with your
micrometer.

One possible use is with a sine bar, when you don't need the
degree of accuracy you can get from gauge blocks -- or don't want to
expose the gauge blocks to the wear involved in work on a surface
grinder.

They are *not* normally used for supporting work being milled.
Still good to have -- but perhaps not for what you were thinking they
were for, since you mention them in connection with vises and milling.

I have the set of end mills -- and they work well when I don't
need larger end mills (I've got up to 1-1/2" plus much larger horizontal
milling cutters.)

I would have to go down and check to see whether they all have
shanks which would fit the set of collets. You might need to add a
5/16" and a 7/16" collet to the sset.

Though not Lyndex these are the best deal I've found. (On eBay):
130362779707

The price looks good. Probably some sizes you won't need.
Things like 13/16" -- but just in case you wind up with an unusual size
of end mill.

[ ... ]

Well, with all this talk of collets... :-)

Yes -- but you are the one who is focused on them to the extent
of selling a new import set to buy the used Lyndex set.

Ijust don't wnat to have to stop several times though out a project to
get something I missed.

But my priority shoul dbe taking the spindle box of my mill/drill
apart to see what the problem is.(Since most of my initial projects
will have to be done on tthat machine).

You didn't say that it had known problems. I thought that it
just needed to be assembled and used.

Likely a stripped nylon gear in the head -- used as an overload
"fuse" to protect more expensive components. This is common in import
machines.

[ ... ]

Oh. Why do so many prefer 3 jaw chucks on their rotary tables?

Because they are quicker to use, are usually *accurate* *enough*
for 99% of the work, and tuning a 4-jaw is a pain, and tuning a 4-jaw on
a rotary table where you have to keep turning the table to check your
progress. (A lot easier on a lathe.)

Nevertheless, a 4" 4 jaw independent chuck would be as close to ideal
as possible between my lathe and rotary table.

I disagree -- but you will learn -- if you ever get around to
actually *using* what you are getting.

I meant as far as a chuck that I can use with both.(Since I already
have the 3" 3 jaw).

O.K. Though I consider the 3-jaw better for most work on the
rotary table.

[ ... ]

The main trick is to be careful (on the lathe) that the jaws
don't stick out far enough to hit the ways of the lathe bed -- or the
arms of the carriage if they stick out towards the headstock end.

Yes. Also, perhaps this oone won't be the one to get, since 3.94" is
it's limit.
http://littlemachineshop.com/product...ProductID=1697


Note that 3.94" is the result of converting 100 mm to inches.
It can certainly make that last 0.060" of adjustment. :-) And as long as
you don't tighten it down too tight, it should handle that size well.

And this URL:

http://littlemachineshop.com/info/lathechuck.php

shows the *practical* maximum grip with the 4" 4-jaw as 5.0" The 3.94"
is the *rated* capacity.

[ ... ]

Plan on getting the right size counterbore so you can have the
screws which mount the chuck within the thickness of the adaptor plate.
(Which also defines the needed thickness of the adaptor plate probably
twice the height of the screw head.)

I'll have to put "counterbore" in the MSc search to see what I get.

It is a two-flute milling cutter with a pilot to fit the hole to
clear a given size of screw shank so it can be used in a drill press.

Here is an example of what I am talking about -- MSC # 08860207

Looks as though this one is for 5/16" (or 8 mm) socket head cap screws.
It makes a recess so the head does not stick above the surface.

[ ... ]

Yes. BTW. 6-1/4" is the standard size face plate for this mini lathe.

For a face plate -- not for a dog driving plate.

You kind of lost me the first time you mentioned "Dog driving plate".
You mean a plate for the lathe dogs?

Yes. It typically has one slot which extends out through the
edge, an opposite slot which goes closer to the center, and sometimes
more slots on the sides, so you can find someplace to tuck the tail of
any reasonable size of bent-tail dog.

[ ... ]

BTW -- note that the collet adaptor nosepiece itself says:

'The 3C collet bore is concentric with the 3 Morse taper within
0.0002".'

so no matter how precise your 3C collets, you'll never be sure of
getting 0.0001" TIR.

I suspect the same accuracy on my 5C collet nosepiece on my
12x24" Clausing, exclusive of errors in the spindle or the collets
themselves.

And I don't expect the collet chuck you are looking at to be
anywhere near this accuracy.

I wonder how often concentric errors cancel each other out when
multiple surfaces are involved.

Well ... it is best if the parts have equal runout and can be
intentionally positioned to cancel. But it is seldom that the errors
are equal enough to totally cancel.

BTW Looking at the Lyndex page, I find this:

http://www.lyndex.com/news_products.asp?id=150

which is the tool for shrink fitting end mill holders to end mills, and
it apparently can also be used for removing broken tools from a
shrink-fit holder.

I can't seem to find a spec on TIR for these collets.

Lyndex collets? They are supposed to be within .0005. The import
collets are said to be "precision" when they are within that.(Going by
all the ads I've read).

So -- how are you expecting to get 0.0001" TIR?

[ ... ]

Just pointing out that the most perfect collets in the world are
still at the mercy of their mounting. If you can't make the mounting
true *first* there is no point to grinding the collets true.

Yes. The collet grinding may be too much so early in my learning
curve.

Starting with checking the TIR on your collet nosepiece and if
necessary, grinding the taper concentric -- if you *insist* on being so
anal about concentricity.

If those import collets don't sell on eBay, I'll check every one of
them. :-)

O.K. You'll need drill rod or drill blanks of each diameter to
test them properly.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Jun 19, 4:31*pm, Searcher7 wrote:
On Jun 19, 3:13*pm, Jim Wilkins wrote:
On Jun 19, 11:25*am, Searcher7 wrote:

On Jun 17, 7:43*am, Jim Wilkins wrote:
On Jun 17, 1:46*am, Searcher7 wrote:
On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
...
...Deflection controls the maximum length you can have protruding
from the chuck or collet. The part inside the spindle is irrelevant.

I thought that the distance between tailstock and headstock would
determine this.

For 2" pipe and light cuts perhaps. 1/8" brass rod yields too much to
turn straight if it protrudes even 1/2".

And I assume deflection is why steady rests were made.

It is, but they can't occupy the same space as the carriage. Follower
rests don't help if the part has shoulders. If you tried to turn a 6"
length of 1/4" aluminum without the tailstock it would just climb up
onto the lathe bit.

Yes. My determination is that with my lathe 9/16" would be the maximum
diameter I could pass through the spindle using 3C collets, because
that is the largest diameter these collets are made for.

Higher than that would require a 5C collet chuck for the 5C collets.

Not if you needed to turn some 3/4" thin walled brass tubing, or thin
a washer, or remove the part to test a fit and then replace it to cut
some more, or turn it around to machine the other end, or file it
without risking precious body parts, or face a batch of pieces to the
same length. An MT3 collet would be fine for all those.

You could make one end of the drawbar serve as the depth stop by
turning it down below the thread roots. I'd bring it out within ~1/2"
of the end. The collet slides further into the spindle as you tighten
it but the drawbar doesn't move.

It also helps if you are making bicycle spokes or threading the ends
of tubing, ...
Of course. But I have no projects like that on the horizon yet.

They aren't on the horizon, they are submarines waiting to torpedo you
with broken lamp and plumbing parts etc. When I bought the lathe I
had no idea that in a few years I would be making antique lawnmower
tires and space laser prototypes on it

MT3 collets use a drawbar, so they are not an option.
Darren Harris

Ask yourself why they are used on rotary tables. An MT2 collet holds
the centering rod he
http://picasaweb.google.com/KB1DAL/H...10360947850418

On the lathe you could do the same to center a gear blank on a
faceplate, I did (with 5C) to turn the OD of that piece. A chuck and
faceplate won't fit at the same time, but you can use a collet with
either, like to hold a depth stop for a chuck.

jsw

On Jun 19, 6:55*pm, Jim Wilkins wrote:
...

On the lathe you could do the same to center a gear blank on a
faceplate, I did (with 5C) to turn the OD of that piece. A chuck and
faceplate won't fit at the same time, but you can use a collet with
either, like to hold a depth stop for a chuck.

jsw

I should have written " use a Morse collet with either", since the 5C
spindle adapter blocks screwing on a chuck. The faceplate fits behind
it.

I have an MT2 rotary table and MT3 horizontal milling machine, plus
MT2 and 3 spindle bushings for the lathe, and occasionally some odd
mix of them solves a problem. For instance I've used the milling
machine arbor as a mandrel to turn bushings.

One of the extra features on Grizzly's gunsmith version of its lathes
is a spider to center the barrel at the left end of the spindle. My
less-precise version uses a cheap 1/2" drill chuck with a centering
shoulder that fits into the collet closer tube. The rod that it's
tightened on holds it in place and it keeps the rod from whipping
around. I pressed handle spokes into the key holes since it doesn't
have to be very tight.

jsw

On Jun 19, 6:41 pm, "DoN. Nichols" wrote:
On 2010-06-19, Searcher7 wrote:

On Jun 18, 5:44 pm, "DoN. Nichols" wrote:
On 2010-06-18, Searcher7 wrote:

[ ... ]

MT3 collets are obviously out. A shame because I was about to jump on
this set: 110544744384

Note that they are described as *milling* collets -- for holding
end mills, not as work holding collets, which is what you are looking
for.

Ok. I guess if I were to use them in the lathe they wouldn't be better
than the MT3 end mills I have.

Other than you could change end mills in the collets. (Or do
you mean end mill *holders*?)

Yes. I see no advantage to using end mills in MT3 holders in my lathe
since I now have a mill/drill. (Unless I decide to use my lathe for
gear cutting). :-)

However -- a collet chuck which will hold 5C collets and which
will mount on the spindle's nose the same way the chuck does will do
that -- at the cost of some of the distance between the spindle nose and
the tailstock center.

I assume this wouldn't be an issue if I'm passing the stock through
the spindle anyway.

It is a loss of rigidity as you extend more distant from the
spindle nose.

Yes. I understand the rigidity part. I was thinking about that the
room the 5C collet chuck taking up would not be an issue in and of
itself when I'm passing stock through the spindle.

Maybe or maybe not. It depends on how long an area of the
workpiece needs machining at a time.

Ok. The only way to improve machinable area without un-clamping is to
turn between centers if the stock diameter larger than the 3C (9/16")
capacity.

Note, BTW, that the smaller the diameter of the workpiece, the
more likely that what sticks out the other end of the spindle will bend
and start to whip.

The higher the spindle speed, the more likely this is to happen,
too.

But -- you can do a nice job of constraining the workpiece with
some PVC pipe running from just past the outboard end of the spindle to
the free end of the workpiece which is not too much larger than the
workpiece. I have two tubes to handle this. One is a 1-1/2" PVC pipe
which fits in a cradle near the far end and is held down by bungee
cords. The other is a similar one, except that it has caps on both ends
which were bored on the lathe to be a precise fit on the OD of a much
smaller PVC pipe with that smaller PVC pipe glued into the caps. This
is used for things as small as 3/16" brass rod.

When it is spinning, the tip tries to move outward, and the
farther it gets from the center line, the more force. The PVC pipe
keeps it from getting far enough to be a problem.

So -- remember to leave room to the left of the spindle for the
long workpieces -- and provisions for supporting a tube to control the
whipping. If it ever *does* get to whipping, it can be very dangerous.
Also -- make sure that the lathe is firmly bolted down.

Ok. I read that three times. I think I'll have to wait for the
video. :-)

A while back when we were discussing milling on the lathe it was
decided that 5C collets would go no where near the spindle, until I
got that 5C collet chuck that is held in a chuck. So in view of
everything perhaps I should put this back on my shopping list:
http://littlemachineshop.com/product...ProductID=3047

The collet chuck if you want the benefit of being able to pass
through the spindle (while held by collets) workpieces between 0.4375"
and 0.748" (the limit set by your spindle -- which appears to be 19 mm
-- and *might* actually pass 3/4" (19.05mm). Check it with some 3/4"
drill rod.

.787" is the size of my spindle bore, which is why I was hoping to
pass through as large as .750".

O.K. You certainly should be able to get that through.

Of course, for workpieces up to 1", you could chuck them in the
collet chuck at least as deep as from the nose of the collet to the
spindle nose adaptor plate -- a little longer than the collet.

I already have 5 collets and a 5C collet chuck would mean I wouldn't
need any more collets.

You really want the 3C collets and drawtube assembly for smaller
diameter workpieces. It is more true than a collet chuck because it
centers on the internal taper of the spindle.

3C it is. (1/16", 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16").

O.K.

But It doesn't look as though I'll find these from Hardinge, Lyndex,
or Royal.

Not likely -- unless you find an old used set. Certainly
Hardinge made them in this size -- the 3C and 5C collets were
*originated* by them, which is why they are a direct fit in the spindle
of their machines.

(BTW. I noticed that eBay sellers like to throw in the name southbend,
even when the collets are of a different brand. As in "for South Bend
lathes" or "for Bridgeport milling machines". As if these collets
would only fit those spcific machines. I assume this is supposed to be
a marketing angle).

Yes -- someone is searching on the name of his machine (those
are the most popular serious machines in the hobby market), and they
find things which could be used in *some* machines by that maker. I hit
the same problem when searching on Clausing. Adding:

-"for Clausing"

to the search string will get some of those out of the listing. :-)

The only disadvantage is that unlike 3C I wouldn't be able to use 5C
in the spindle directly.

Right -- more stick-out from the spindle nose, and loss of
rigidity. And *perhaps* a little more runout -- especially without the
adjust-tru style collet chuck.

So it seems that if I get the 5C collet chuck it should at least be an
Adjust -Tru. (Which would run a couple hundred dollars more).

And -- it will stick out even more. The Adjust-tru takes up
perhaps an inch and a half between the backplate and the body. :-)

But I even though it would be a more advanced project, I haven't given
up on this kit idea.http://www.sc-c.com/metallathe/MLA21.html

Yes -- that is a good choice. And since the taper is machined
on the machine on which it is going to be used, as long as you make your
backplate fit the spindle nose precisely, you should have better
concentricity than on any pre-machined one you would buy.

He makes good things.

Thanks. Then I'll definitely have to concentrate on learning
everything I need to know and use that option.

But wait. Wouldn't the option of passing stock through the spindle
tend to negate the disadvantages of that "poor man's" collet chuck I
have that would hang out over the lathe bed?
http://s290.photobucket.com/albums/l.../Tools/?action...

No -- you don't have enough jaw depth to really grip that firmly
enough. You would have a serious loss of rigidity. And you have to
remove it from the chuck to loosen the collet (IIRC), so you would have
to tune your 4-jaw chuck back to center after each workpiece change.

I guess this is where the 3 jaw would be better. But I guess I can use
it for turning something like Delrin anyway.(I just checked and the 4'
to 5' rods I have are about 3/4", so that is still in 3C territory).
And I'm assuming I wouldn't need collets anyway with a chuck attached.

Well, I'll be doing mostly one-offs.(With a few two-offs mixed
in). :-)

But you don't really have a feel for just how awkward to use
this would be. :-)

So it's looking like I should toss that "poor man's" 5C collet chuck
back up on eBay. :-)

Nevertheless, I can still use the collet stop with 5C collets for
repeatability.

Yes -- hmmm *maybe* with the collet chuck you are considering
you don't have much room behind the collet before you hit the backplate.

Well, since the collets stops are cheap there is only one way to find
out. :-)

O.K.

[ ... ]

If it existed I probably would have come across it, which means it
would probably be a project for someone with experience.

O.K. Or you after you *get* more experience. Your really need
to assemble your mill and start using it and the lathe, just to get a
feel for what I am talking about.

Yeah. I've been bouncing back and forth between the lathe and mill/
drill because I keep running into walls.(I still have to get that tool
post milled down before I mount it with the modified compund to my
lathe).

Which means that you want to get the mill working *first*. Or
-- learn to use the lathe with the toolpost which is supplied, so you
will appreciate the quick-change when you have it in service.

Oh yes -- do you have the dovetail cutters needed to clean up
the width of the dovetail?

I'm working on that. So far all I know is I need 60 degrees cutters
and an R8 shank. (Or straight shank if I have the R8 collets).

My LMS options are as follows:
http://littlemachineshop.com/product...ProductID=2905
http://littlemachineshop.com/product...ProductID=2906
http://littlemachineshop.com/product...ProductID=2904

(And an end mill for milling my original compound down to the same
dimensions as my new one from LMS. (I need the practice)).
http://littlemachineshop.com/product...ProductID=1952

There is an exception to this -- Hardinge lathes have a spindle
which *directly* accepts the 3C or 5C collet (depending on lathe size).

Since my lathe will *directly* accept 3C collets, perhaps I should get
several anyway.

Actually -- it does not *directly* accept the 3C collets. It
needs a nosepiece adaptor, which is shown in the quoted URL below.

http://littlemachineshop.com/product...ProductID=2240

Ok. I meant no collet chuck is needed. :-)

O.K. That I will accept.

Note that the collet closer sets *include* this, so you don't
have to buy it separately.

Yes. But I wonder if these on eBay are a better deal than the two LMS
link below: 130371901373 390079264989

http://littlemachineshop.com/product...ProductID=1991
http://littlemachineshop.com/product...ProductID=2374

Well ... the collet set includes some extra sizes in the eBay
auction. The LMS set has seven, and the eBay auction has nine. It adds
a 1/16" on the small end, and a 9/16" (short grip) on the large end.
This might be a good one to go for. It does cost more but both sources
are about $10.00 per collet.

But note that the nosepiece adaptor is only *part* of what you
need to hold the collets -- and it is all that the eBay auction is
offering. Remember the drawtube which is part of the LMS kit. Since
the kit *includes* the collet adaptor, the fact that you can get another
adaptor for not too much still does not save you anything. And no clue
as to whether it is more or less accurate than the one which is part of
the kit.

For all intents and purposes I'm considering them both the same.(After
all they won't be coming from Hardinge. :-)

Nevertheless, LMS would be about $170 for the complete collet closer
and 7 3C collets.

And eBay will give me all 9 3c Collets and a spindle adapter for $117.

So the question is if saving $50 is worth having to make a drawtube.

Have you yet put your 3-jaw chuck on the lathe and *done*
anything with it? Really -- get some experience playing with it.

It is already on the lathe, since that is the supplied chuck.(The
original toolpost which I didn't bother getting tools for is still on
the lathe also.

You might still be able to use the tools in the existing
toolpost -- or at least some of them. Gain some experience that way.

That's just it. I have no tools for the OEM tool post, because I was
anticipating using the AXA with the lathe.

The MT3 has an internal thread, and requires a solid drawbar,
usually tightened with a wrench instead of a handwheel -- but you could
use a handwheel if you so desired. I, personally, would not use MT3
collets for many things -- though having a standard Morse taper spindle
on the dividing head would make finding centers easier. :-)

This is what I'll also use my lathe tailstock's MT2 dead center for.
Not just for my lathe tailstock. (I'll need a good way to center the
rotary table).

O.K. Or you could sweep out the ID of the Morse taper in the
rotary table just as well.

"Sweep out?"

O.K. I was shifting the meaning of "finding centers" to getting
the table truly concentric under the spindle of the machine. You use an
indicator such as the Starrett "Last Word", or one of the better ones
from other makers, held in the spindle and feeling the ID of the taper.
You adjust the position so the indicator reading does not change as you
rotate the spindle through a full 360 degrees. If you have room for it,
a "Blake coax" indicator is more convenient, as the dial faces you
through the full rotation.

And they want $90 for a used one: 110548805095 :-(

With the mill/drill, spin indexer and hor./vert. collet fixture the
collet blocks are now in the "what do I do with..." category.

They may fit your mill better than the spin indexer. And both
the spin indexer and the collet blocks use the same collets, which is a
help.

Fit my mill?

Put a round workpiece in the collet in the collet block, and
clamp the collet block horizontally in the milling vise to mill a flat on
the side of the workpiece -- or to mill a keyway in the round piece
depending on your needs. The combination of the vise (especially
without the rotary base installed) and the horizontal collet block will
be lower than either the spin indexer or an index head, so more room for
tooling between the spindle nose and the workpiece.

Ok. That's what you meant.

Yes. I used just such a setup in my horizontal mill yesterday,
using Woodruff Key cutters to make cuts down to a center bore to allow
punchings to exit from repeated use of the punch (which I had made) in a
motorized punch press. This is specifically for making a large number
of felt disks to cushion the travel of English Concertina buttons so
they don't click when they bottom.

[ ... ]

This was the original plan:http://littlemachineshop.com/product...ProductID=3489

This is a good start -- including a Kurt style milling vise,
which has the benefit that as it tightens it pulls the moving jaw (and
thus the workpiece) down towards the bed of the vise -- reducing the
needed pounding with a plastic or lead-filled leather mallet.

But after reading I decided a screw vise would be better.

A "screw vise"? You mean a toolmaker's vise with a screw at a
45 degree angle? (Often actually called a "screwless vise".) Those
maker more sense on smaller machines, (such as my baby Emco-Maier C5
mill, which uses ER-25 collets), or on surface grinders where they are
held down by the magnetic chuck.

Yeah. Screwless. :-)

It is more precise -- but much more awkward to use. Go back to
your LMS site and read:

http://littlemachineshop.com/info/vise_compare.php

The vise in the kit is what they call "Precision Milling Vise",
and is far better for most things done on the mill. That vise is
paterened on the "Kurt Anglock" and is *much* quicker to use. I have
three different sizes of these.

Ok. So "quicker" is it's main selling point over the screwless?

It does cover R8 collets. (But no wavy parallels). :-)

Note that the parallel set included goes up to 1-5/8", while the
jaws of the vise ar only 1.04" deep, so only 5 of the 10 parallels will
do you any good -- at least until you get a bigger mill and vise.

Well, the screwless thwy sell allow use of all but one.
http://littlemachineshop.com/product...ProductID=2356

It could be used in addition to the Kyrt style milling vise,
especially to hold things which need to be moved from the mill to
another tool. The "screwless" vise can be held crosswise in the Kurt,
the milling operation performed, and them moved to another tool, still
holding the workpiece. But get the Kurt style *first*.

Ok. I was just about to order this when you threw that curve ball. :-)
http://www.use-enco.com/CGI/INSRIT?P...PMAKA=428-9126

(I'm looking to get wavy and also adjustable parallels anyway).

I don't have the wavy parallels so far, and don't feel the need.
As for the adjustable parallels -- they serve a different set of
functions -- mostly transferring measurements between awkward places and
micrometers -- either direction -- set the parallel to a micrometer and
then use it as a reference for positioning something -- or set the
parallel to fit a slot, and then measure the parallel with your
micrometer.

One possible use is with a sine bar, when you don't need the
degree of accuracy you can get from gauge blocks -- or don't want to
expose the gauge blocks to the wear involved in work on a surface
grinder.

They are *not* normally used for supporting work being milled.
Still good to have -- but perhaps not for what you were thinking they
were for, since you mention them in connection with vises and milling.

I only mentioned parallels because they are a part of that "value
package" I was about to get from LMS. And I figured the adjustable
ones would serve better.

I have the set of end mills -- and they work well when I don't
need larger end mills (I've got up to 1-1/2" plus much larger horizontal
milling cutters.)

I would have to go down and check to see whether they all have
shanks which would fit the set of collets. You might need to add a
5/16" and a 7/16" collet to the sset.

Though not Lyndex these are the best deal I've found. (On eBay):
130362779707

The price looks good. Probably some sizes you won't need.
Things like 13/16" -- but just in case you wind up with an unusual size
of end mill.

I had committed myself to at least get only established "high quality"
5C collets in 1/16ths. But I sense that you don't think I should be
that concerned with getting the same quality standard in 3C for my
lathe, or R8 for my mill/drill, and that I probably wouldn't notice
much of a different in my finished work using the eBay collets.(And I
don't know it accuracy is just as important in a tool holding collet
as in a work holding collet, anyway).

Well, with all this talk of collets... :-)

Yes -- but you are the one who is focused on them to the extent
of selling a new import set to buy the used Lyndex set.

Ijust don't wnat to have to stop several times though out a project to
get something I missed.

But my priority shoul dbe taking the spindle box of my mill/drill
apart to see what the problem is.(Since most of my initial projects
will have to be done on tthat machine).

You didn't say that it had known problems. I thought that it
just needed to be assembled and used.

Likely a stripped nylon gear in the head -- used as an overload
"fuse" to protect more expensive components. This is common in import
machines.

Yes. That's what I guessed it was. I'll be concentrating on figuring
out how to take it apart over the next couple of days.

Oh. Why do so many prefer 3 jaw chucks on their rotary tables?

Because they are quicker to use, are usually *accurate* *enough*
for 99% of the work, and tuning a 4-jaw is a pain, and tuning a 4-jaw on
a rotary table where you have to keep turning the table to check your
progress. (A lot easier on a lathe.)

Nevertheless, a 4" 4 jaw independent chuck would be as close to ideal
as possible between my lathe and rotary table.

I disagree -- but you will learn -- if you ever get around to
actually *using* what you are getting.

I meant as far as a chuck that I can use with both.(Since I already
have the 3" 3 jaw).

O.K. Though I consider the 3-jaw better for most work on the
rotary table.

That's probably where I'll keep it. (When not doing any gear cutting).

The main trick is to be careful (on the lathe) that the jaws
don't stick out far enough to hit the ways of the lathe bed -- or the
arms of the carriage if they stick out towards the headstock end.

Yes. Also, perhaps this oone won't be the one to get, since 3.94" is
it's limit.
http://littlemachineshop.com/product...ProductID=1697

Note that 3.94" is the result of converting 100 mm to inches.
It can certainly make that last 0.060" of adjustment. :-) And as long as
you don't tighten it down too tight, it should handle that size well.

And this URL:

http://littlemachineshop.com/info/lathechuck.php

shows the *practical* maximum grip with the 4" 4-jaw as 5.0" The 3.94"
is the *rated* capacity.

Ok. And by coincidence that vise says 3.94 capacity:
http://littlemachineshop.com/product...ProductID=2356

You think I can squeeze out 4"? :-)

Plan on getting the right size counterbore so you can have the
screws which mount the chuck within the thickness of the adaptor plate.
(Which also defines the needed thickness of the adaptor plate probably
twice the height of the screw head.)

I'll have to put "counterbore" in the MSc search to see what I get.

It is a two-flute milling cutter with a pilot to fit the hole to
clear a given size of screw shank so it can be used in a drill press.

Here is an example of what I am talking about -- MSC # 08860207

Looks as though this one is for 5/16" (or 8 mm) socket head cap screws.
It makes a recess so the head does not stick above the surface.

Yes. As luck would have it I read the whole chapter on counter boring
in Machine Shop Essentials earlier. Counterboring operations are
mostly for the drill press, with the mill used for slanted surfaces.
(I'll have to see if there are any counterboring/spotfacing sets to
cover all bases).

Yes. BTW. 6-1/4" is the standard size face plate for this mini lathe.

For a face plate -- not for a dog driving plate.

You kind of lost me the first time you mentioned "Dog driving plate".
You mean a plate for the lathe dogs?

Yes. It typically has one slot which extends out through the
edge, an opposite slot which goes closer to the center, and sometimes
more slots on the sides, so you can find someplace to tuck the tail of
any reasonable size of bent-tail dog.

And all this time I thought that lathe dogs were only used with face
plates.

BTW -- note that the collet adaptor nosepiece itself says:

'The 3C collet bore is concentric with the 3 Morse taper within
0.0002".'

so no matter how precise your 3C collets, you'll never be sure of
getting 0.0001" TIR.

I suspect the same accuracy on my 5C collet nosepiece on my
12x24" Clausing, exclusive of errors in the spindle or the collets
themselves.

And I don't expect the collet chuck you are looking at to be
anywhere near this accuracy.

I wonder how often concentric errors cancel each other out when
multiple surfaces are involved.

Well ... it is best if the parts have equal runout and can be
intentionally positioned to cancel. But it is seldom that the errors
are equal enough to totally cancel.

BTW Looking at the Lyndex page, I find this:

http://www.lyndex.com/news_products.asp?id=150

which is the tool for shrink fitting end mill holders to end mills, and
it apparently can also be used for removing broken tools from a
shrink-fit holder.

I can't seem to find a spec on TIR for these collets.

Lyndex collets? They are supposed to be within .0005. The import
collets are said to be "precision" when they are within that.(Going by
all the ads I've read).

So -- how are you expecting to get 0.0001" TIR?

Well, I'm not expecting. I'm just trying to minimize one particular
source of error. (I always so that we can never achieve perfection,
but it is our strive for perfection that makes us great). :-)

Just pointing out that the most perfect collets in the world are
still at the mercy of their mounting. If you can't make the mounting
true *first* there is no point to grinding the collets true.

Yes. The collet grinding may be too much so early in my learning
curve.

Starting with checking the TIR on your collet nosepiece and if
necessary, grinding the taper concentric -- if you *insist* on being so
anal about concentricity.

If those import collets don't sell on eBay, I'll check every one of
them. :-)

O.K. You'll need drill rod or drill blanks of each diameter to
test them properly.

Not something I think I can get at Home Depot. Nevertheless,
concentricity will be the first thing I look into.

Thanks a lot.

Darren Harris
Staten Island, New York.

On Jun 20, 1:58*am, Searcher7 wrote:
On Jun 19, 6:41 pm, "DoN. Nichols" wrote:
On 2010-06-19, Searcher7 wrote:
On Jun 18, 5:44 pm, "DoN. Nichols" wrote:
On 2010-06-18, Searcher7 wrote:
...
* * * * Note, BTW, that the smaller the diameter of the workpiece, the
more likely that what sticks out the other end of the spindle will bend
and start to whip.

* * * * The higher the spindle speed, the more likely this is to happen,
too.

* * * * But -- you can do a nice job of constraining the workpiece with
some PVC pipe running from just past the outboard end of the spindle to
the free end of the workpiece which is not too much larger than the
workpiece. *I have two tubes to handle this. *One is a 1-1/2" PVC pipe
which fits in a cradle near the far end and is held down by bungee
cords. *The other is a similar one, except that it has caps on both ends
which were bored on the lathe to be a precise fit on the OD of a much
smaller PVC pipe with that smaller PVC pipe glued into the caps. *This
is used for things as small as 3/16" brass rod.

* * * * When it is spinning, the tip tries to move outward, and the
farther it gets from the center line, the more force. *The PVC pipe
keeps it from getting far enough to be a problem.

* * * * So -- remember to leave room to the left of the spindle for the
long workpieces -- and provisions for supporting a tube to control the
whipping. *If it ever *does* get to whipping, it can be very dangerous.
Also *-- make sure that the lathe is firmly bolted down.

Ok. I read that three times. I think I'll have to wait for the
video. :-)

This is a commercial unit:
http://www.tornos.ch/pd/bl-sbf216-mc.jpg

The lathe is under the curved clear covers. The blue and white machine
constrains the spinning rod and also stores and feeds new ones in as
they are used up. The simpler version DoN described, clearly, could be
a length of pipe on sawhorses.

It would be on the other side of a manual lathe like ours, but I
didn't find a good picture of that.

jsw

On 2010-06-25, Searcher7 wrote:
On Jun 24, 1:12 am, "DoN. Nichols" wrote:
On 2010-06-24, Searcher7 wrote:

[ ... ]

It looks like this whole thing must be re-thought. I had been thinking
of the black part as the base and can believe I didn't think of
something before. IT is actually the fron when screwed intot he silver
body. And the collet fits in it nicely.
http://s290.photobucket.com/albums/l.../Tools/?action...

O.K. That is *good*. you only need access to the back to
change collets. The large black ring is used to close the collets onto
the workpiece, and it is in front so you don't have to work between
jaws.

I can then screw the ring on at the rear.
http://s290.photobucket.com/albums/l.../Tools/?action...

So obviously this was not made for a normal lathe set-up, and the
black front is obviously how it is supposed to be secured in whatever
machine it is supposed to be used.

Absolutely not! The black front is what is adjusted to close or
open the collets. It is *not* for mounting the thing to something else.

And -- it has an advantage over normal collet chucks. Normally
the collet is drawn back in the process of closing the collet, and
slightly different diameters are drawn back differing amounts. With
*this* one, the collet is held at a constant depth and the closing taper
moves towards the tailstock to close the collet.

Ok. Understood. But that brings up a possible issue I'll mention
below.

O.K.

[ ... ]

I can see it being held in a large collet in a really large
lathe.

I assume that such a lathe would have the option of using a variety of
these collets with different standards along with 5C.

Such a lathe would have (if any) a very large collet -- useful
for large diameter workpieces at slow spindle speeds. they typically
don't have very fast maximum spindle speeds, as those can cause a big
chuck to "grenade". Each chuck should have a maximum speed rating,
though small ones are likely to not have it marked.

I can also see it being used in a fixture to hold workpieces in
a mill.

I'd like to see a picture/video of such a fixture. :-)

Well ... there are dozens of possibilities depending on what is
being held and machined.

There, one of the threaded holes would get a short bar screwed
into it with a large ball handle on the end for tightening and
loosening. (Not when using it in a rotating chuck of course, because
the handle would unbalance things -- unless you had three identical
handles screwed in at 120 degree intervals.

Actually, that would be four at 90 degrees.

Oh -- eight holes total, not the six I thought there were? I
never had a view which made it truly clear.

[ ... ]

The small bar I still think might be used to turn the small ring
onto the end of the collet and back off.

There is no place for the small bar. The ring that threads onto the
rear of the collet is solid, and actually threads about halfway on
before it bottoms out.(But I assume that is enough).

The small ring has a series of depressions around the OD. If
the spacing between that and the wall surrounding it is just right, the
pin on one end could be slid into a depression and used to chase it
around with the outer wall keeping it engaged.

So I'd have to create an adapter that secures this chuck *at the
front*, while also creating a seat for it at the rear.

No! You would create an adaptor which mounts on the spindle
nose which has a cylindrical bore which is a slip fit for the OD of the
device, is deep enough to hold the body, but to leave the large black
ring accessible, and with a thin slot along the length of the bore and
some means of compressing it to hold the body.

Like a large collet or split bushing I assume. (Since the body of the
collet chuck is 2.75" long that would be a deep seat).

Yes -- except that the bushing would mount directly on the
spindle nose instead of through an adaptor.

[ ... ]

Toss those ideas. The threaded holes are *not* for mounting it,
they are for rods to turn the large black ring to tighten the collet and
loosen it. The smooth holes used when in a lathe chuck type setup with
the large bar slid in to turn it and removed before spinning the
spindle. The threaded holes for a ball-ended bar for opening and
closing it when it is mounted in a mill.


Ok, the small ring is to secure the collet, and the large front part
of the collet chuck is to secure the work in the collet.

Yes.

So here is the problem. What is to keep the front of the collet chuck
from rotating clockwise relative to the body under cutting forces,
which would result in opening the collet.(And making things really
exciting). :-)

Well ... normally the anti-rotation pin is not expected to
handle much torque -- but here it might have to.

Can you verify which direction of rotation closes the collet
(moves the large black ring away from the body)? Is it left-hand thread
or right-hand thread? If it is a left-hand thread, the cutting forces
would *tighten* it, thus preventing your problem.

If not -- then it is likely intended to hold a workpiece on a
surface grinder or other low force operation.

[ ... ]

Again -- forget it. You're thinking of the large black ring the
wrong way. It *has* to be free to turn so you can loosen and tighten
the collets.

But how does one keep it from turning under cutting forces?

Pray that the anti-rotation pin works? Look for a place where
the small pin slides into to prevent it from turning? Add provisions
for clamping the ring to the sleeve which holds the body? Run your
lathe spindle in reverse? (I think that is not an option on your lathe
anyway.)

And instead of using the ring at the rear of the chuck, I'd use a
drawtube, if I can modify the machine to use a modified 5C spindle.
(Just throwing out ideas). :-)

You can't make your current machine have a large enough through
diameter to work that way. For a 5C collet closer, you need at least a
1-3/8" through bore, not your near 3/4".

Yes. That is why I am investigating installing a 5C spindle. I just
may have to shorten a drawtube shortening one. And the worse case
scenario would be a need for a different set of gears, if I can't
enlarge the center hole of the existing ones that directly drive the
spindle the spindle.

Of course I'll have to open up the headstock so I can see and measure
what is possible.

I expect that you will find that the entire OD of the spindle is
smaller than the needed bore through the spindle for a 5C collet closer.
Without actually going down and measuring, I think that the OD of the
bearings on my Clausing 12x24" with a 1-3/8" spindle bore is on the
order of 5" -- which I think is larger than the dimensions of your
headstock in the area where the bearings live.

[ ... ]

One possibility is that you could file or sand off some of the
mating surface where the wedge slides against the dovetail. Or if there
is a chip or a burr in there, that could explain the fit problem -- it
would force the dovetail to be too wide.

I assume you mean the filing/sanding the wedge itself, correct? And
wouldn't that put more play into the assembly.

Yes -- but it does not matter -- the wedge is trapped between
the angled surface on the post body's dovetail and the inside of the
holder's dovetail. A little play there won't hurt when you have holders
which will not fit onto the post. And it will not be as critical a
surface as the dovetail itself.

And the wedges are more replaceable than the toolpost body. :-)

They would cost less -- if you could find a place to buy them
separate from the toolpost.

But I think that they would be easier to file or sand down in the
critical area.

[ ... ]

How are you going to maintain the *angle* of the dovetail? That
is important to the proper gripping.

I guess I could think up a jig or some sort.

Perhaps -- but I would go for the side of the wedge myself.

I'm assuming that a jig wouldn't be needed to accurately remove
material equally along the length of the wedges.

If you have a flat surface on the wedge which meets the
dovetail's angles surface, you can probably simply slide that face flat
on some fine emery paper on a hard flat surface.

[ ... ]

In the place which makes it most difficult to *legally* own a
gun. :-)

OT: I've worked with guys who became police officers and some may be
retired by now. I had scored in the 90s on the test but was denied
after the physical.(Possibly because of the four pins in my knee,
which kept me out of the Navy).

When the guns laws were made more stringent the number of security
officers in New York State dropped.

When was that? I thought that the NYC laws have been very tight
since at least about when Kennedy was assassinated.

Washington DC has been forced to relax their firearms laws
recently.

Businesses preferred off duty and
retired police officers because they were cheaper and legally safer.
Cheaper because there are no "middle men"(security company) involved.
And legally safer because off duty and retired cops can do a lot more
legally, and get away with a lot more legally than security guards.

So the ironic thing is that the police officers who make much more,
have more benefits, a competent union, and a pension (that is more
than I make working) are also taking away security guard positions
from armed guards when they are not on the clock.

Until something happens which needs the force working overtime,
leaving a lot of places without guards. :-)

[ ... ]

[ ... Blake Coax indicator ... ]

And they want $90 for a used one: 110548805095 :-(

Depends on your luck. And there are import versions which might
show up on eBay for a lot less than a genuine Blake.

I assume like this: 400127581321

Yes -- that shows you a top price for a new one (I think).

So I'll have to be patient.(Beside equipment for tramming is a bigger
priority at the moment).

Actually -- it is also useful for tramming the mill column, and
for adjusting the lathe tailstock offset back to zero -- or checking if
it is still at zero. :-)

Then I guess that is all I'd need for those purposes.

Yes -- as long as there is room between the spindle and the
workpiece. Sometimes things are just too crowded for a Blake.

Thanks. Tramming is the priority. I can use other ways to measure the
workpiece on the table.

O.K. One thing to keep your eyes open for is a fairly large
diameter outer race for a tapered roller bearing -- one about as large
in diameter as the width of the table. You roughly center that under
the spindle, and run the feeler of the Blake around on that. That way,
you don't have the problem of the feeler dropping into the T-slots every
so many degrees.

Oh yes -- a Blake can be turned under power -- but only up to a
certainly rather slow limit. My lathe, with a 55 RPM minimum speed is
well within that. No bets on yours, so you would have to turn the
spindle by hand. Same is likely for the mill.

[ ... ]

These are all of the *largest* eBay vises I could use:

380087874872
300373085985
280518320722
230486712282

O.K. Nominally 3" chucks. I kind of like the first two more,
for various reasons. But is the second one a shars? And they are the
makers/importers of the troublesome toolpost?

Actually I found the invoice. The tool post I have was gotten from
800watt.(And they are notorious for having bad customer service).

O.K.

Just as a point of information, MSC's price for the AXA
(Series-100) size toolpost alone is $211.02 when not on sale.

[ ... ]

And from what I know pick-up is allowed.(Unless what youorder is
coming from another location).

There is no storefront which I can walk up to here, but I
believe that you can phone in an order to be picked up at the storefront.
That would eliminate problems with delivery times being while you were
at work.

Eliminating shipping costs on the heavier orders would be the real
advantage.

Yes.

Good luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Fri, 25 Jun 2010 04:10:24 +0000, DoN. Nichols wrote:
On 2010-06-25, Searcher7 wrote:
[re large black ring on an unusual 5C collet closer]
But how does one keep it from turning under cutting forces?

Pray that the anti-rotation pin works? Look for a place where
the small pin slides into to prevent it from turning? Add provisions
for clamping the ring to the sleeve which holds the body? Run your
lathe spindle in reverse? (I think that is not an option on your lathe
anyway.)
....

Reverse rotation is a standard feature on Sieg 7x10/12/14 minilathes.
In first picture* at http://www.mini-lathe.com/Features/features.htm
three controls are visible above the words "Mini Lathe" -- a bat-handle
3-position toggle switch for motor Forward/Off/Reverse, a Power On/Off
rocker switch, and the speed pot. The 4th and 6th pictures**, about
halfway thru the file, show the Forward/Neutral/Reverse gear lever that
controls leadscrew rotation relative to spindle rotation. (The next
picture after that shows the bolt holes in the nose of the spindle and
the thru-spindle hole.)

* Also http://www.mini-lathe.com/Mini_lathe/features/Controls_y.jpg,
the 4th-from-last picture, has a clearer view of the switches and pot.
Boxed RPM numbers apply when High/Low lever is in Low.

** http://www.mini-lathe.com/Mini_lathe/features/Levers_y.jpg

--
jiw

On 2010-06-25, James Waldby wrote:
On Fri, 25 Jun 2010 04:10:24 +0000, DoN. Nichols wrote:
On 2010-06-25, Searcher7 wrote:
[re large black ring on an unusual 5C collet closer]
But how does one keep it from turning under cutting forces?

Pray that the anti-rotation pin works? Look for a place where
the small pin slides into to prevent it from turning? Add provisions
for clamping the ring to the sleeve which holds the body? Run your
lathe spindle in reverse? (I think that is not an option on your lathe
anyway.)
...

Reverse rotation is a standard feature on Sieg 7x10/12/14 minilathes.
In first picture* at http://www.mini-lathe.com/Features/features.htm

Hmm ... one minor problems with the URL above.

You left out the second "Mini_Lathe" in the url. It should be
like this:

http://www.mini-lathe.com/Mini_lathe/Features/features.htm



three controls are visible above the words "Mini Lathe" -- a bat-handle
3-position toggle switch for motor Forward/Off/Reverse, a Power On/Off
rocker switch, and the speed pot. The 4th and 6th pictures**, about
halfway thru the file, show the Forward/Neutral/Reverse gear lever that
controls leadscrew rotation relative to spindle rotation. (The next
picture after that shows the bolt holes in the nose of the spindle and
the thru-spindle hole.)

O.K. That gives me a better feel for how this lathe is set up.

Thanks.

* Also http://www.mini-lathe.com/Mini_lathe/features/Controls_y.jpg,
the 4th-from-last picture, has a clearer view of the switches and pot.
Boxed RPM numbers apply when High/Low lever is in Low.

Is the gearing in that all metal, or are the gears in part
plastic?

Awkward location for those levers.

** http://www.mini-lathe.com/Mini_lathe/features/Levers_y.jpg

Looking at the motor control panel, I see a screw with a stack
of nuts at the opper left -- looking sort of like a terminal post for
multiple ring terminals to attach to -- perhaps as safety grounds?

Thanks,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Jun 25, 12:10*am, "DoN. Nichols" wrote:
On 2010-06-25, Searcher7 wrote:

On Jun 24, 1:12 am, "DoN. Nichols" wrote:
On 2010-06-24, Searcher7 wrote:

* * * * [ ... ]

It looks like this whole thing must be re-thought. I had been thinking
of the black part as the base and can believe I didn't think of
something before. IT is actually the fron when screwed intot he silver
body. And the collet fits in it nicely.
http://s290.photobucket.com/albums/l.../Tools/?action....

* * * * O.K. *That is *good*. *you only need access to the back to
change collets. *The large black ring is used to close the collets onto
the workpiece, and it is in front so you don't have to work between
jaws.

I can then screw the ring on at the rear.
http://s290.photobucket.com/albums/l.../Tools/?action....

So obviously this was not made for a normal lathe set-up, and the
black front is obviously how it is supposed to be secured in whatever
machine it is supposed to be used.

* * * * Absolutely not! *The black front is what is adjusted to close or
open the collets. *It is *not* for mounting the thing to something else.

* * * * And -- it has an advantage over normal collet chucks. *Normally
the collet is drawn back in the process of closing the collet, and
slightly different diameters are drawn back differing amounts. *With
*this* one, the collet is held at a constant depth and the closing taper
moves towards the tailstock to close the collet.

Ok. Understood. But that brings up a possible issue I'll mention
below.

* * * * O.K.

* * * * [ ... ]

* * * * I can see it being held in a large collet in a really large
lathe.

I assume that such a lathe would have the option of using a variety of
these collets with different standards along with 5C.

* * * * Such a lathe would have (if any) a very large collet -- useful
for large diameter workpieces at slow spindle speeds. *they typically
don't have very fast maximum spindle speeds, as those can cause a big
chuck to "grenade". *Each chuck should have a maximum speed rating,
though small ones are likely to not have it marked.

I can also see it being used in a fixture to hold workpieces in
a mill.

I'd like to see a picture/video of such a fixture. :-)

* * * * Well ... there are dozens of possibilities depending on what is
being held and machined.

There, one of the threaded holes would get a short bar screwed
into it with a large ball handle on the end for tightening and
loosening. *(Not when using it in a rotating chuck of course, because
the handle would unbalance things -- unless you had three identical
handles screwed in at 120 degree intervals.

Actually, that would be four at 90 degrees.

* * * * Oh -- eight holes total, not the six I thought there were? *I
never had a view which made it truly clear.

* * * * [ ... ]

* * * * The small bar I still think might be used to turn the small ring
onto the end of the collet and back off.

There is no place for the small bar. The ring that threads onto the
rear of the collet is solid, and actually threads about halfway on
before it bottoms out.(But I assume that is enough).

* * * * The small ring has a series of depressions around the OD. *If
the spacing between that and the wall surrounding it is just right, the
pin on one end could be slid into a depression and used to chase it
around with the outer wall keeping it engaged.

So I'd have to create an adapter that secures this chuck *at the
front*, while also creating a seat for it at the rear.

* * * * No! *You would create an adaptor which mounts on the spindle
nose which has a cylindrical bore which is a slip fit for the OD of the
device, is deep enough to hold the body, but to leave the large black
ring accessible, and with a thin slot along the length of the bore and
some means of compressing it to hold the body.

Like a large collet or split bushing I assume. (Since the body of the
collet chuck is 2.75" long that would be a deep seat).

* * * * Yes -- except that the bushing would mount directly on the
spindle nose instead of through an adaptor.

* * * * [ ... ]

* * * * Toss those ideas. *The threaded holes are *not* for mounting it,
they are for rods to turn the large black ring to tighten the collet and
loosen it. *The smooth holes used when in a lathe chuck type setup with
the large bar slid in to turn it and removed before spinning the
spindle. *The threaded holes for a ball-ended bar for opening and
closing it when it is mounted in a mill.

Ok, the small ring is to secure the collet, and the large front part
of the collet chuck is to secure the work in the collet.

* * * * Yes.

So here is the problem. What is to keep the front of the collet chuck
from rotating clockwise relative to the body under cutting forces,
which would result in opening the collet.(And making things really
exciting). :-)

* * * * Well ... normally the anti-rotation pin is not expected to
handle much torque -- but here it might have to.

* * * * Can you verify which direction of rotation closes the collet
(moves the large black ring away from the body)? *Is it left-hand thread
or right-hand thread? *If it is a left-hand thread, the cutting forces
would *tighten* it, thus preventing your problem.

* * * * If not -- then it is likely intended to hold a workpiece on a
surface grinder or other low force operation.

* * * * [ ... ]

* * * * Again -- forget it. *You're thinking of the large black ring the
wrong way. *It *has* to be free to turn so you can loosen and tighten
the collets.

But how does one keep it from turning under cutting forces?

* * * * Pray that the anti-rotation pin works? *Look for a place where
the small pin slides into to prevent it from turning? *Add provisions
for clamping the ring to the sleeve which holds the body? *Run your
lathe spindle in reverse? *(I think that is not an option on your lathe
anyway.)

And instead of using the ring at the rear of the chuck, I'd use a
drawtube, if I can modify the machine to use a modified 5C spindle.
(Just throwing out ideas). :-)

* * * * You can't make your current machine have a large enough through
diameter to work that way. *For a 5C collet closer, you need at least a
1-3/8" through bore, not your near 3/4".

Yes. That is why I am investigating installing a 5C spindle. I just
may have to shorten a drawtube shortening one. And the worse case
scenario would be a need for a different set of gears, if I can't
enlarge the center hole of the existing ones that directly drive the
spindle the spindle.

Of course I'll have to open up the headstock so I can see and measure
what is possible.

* * * * I expect that you will find that the entire OD of the spindle is
smaller than the needed bore through the spindle for a 5C collet closer.
Without actually going down and measuring, I think that the OD of the
bearings on my Clausing 12x24" with a 1-3/8" spindle bore is on the
order of 5" -- which I think is larger than the dimensions of your
headstock in the area where the bearings live.

* * * * [ ... ]

One possibility is that you could file or sand off some of the
mating surface where the wedge slides against the dovetail. Or if there
is a chip or a burr in there, that could explain the fit problem -- it
would force the dovetail to be too wide.

I assume you mean the filing/sanding the wedge itself, correct? And
wouldn't that put more play into the assembly.

* * * * Yes -- but it does not matter -- the wedge is trapped between
the angled surface on the post body's dovetail and the inside of the
holder's dovetail. *A little play there won't hurt when you have holders
which will not fit onto the post. *And it will not be as critical a
surface as the dovetail itself.

And the wedges are more replaceable than the toolpost body. :-)

* * * * They would cost less -- if you could find a place to buy them
separate from the toolpost.

* * * * But I think that they would be easier to file or sand down in the
critical area.

* * * * [ ... ]

How are you going to maintain the *angle* of the dovetail? That
is important to the proper gripping.

I guess I could think up a jig or some sort.

* * * * Perhaps -- but I would go for the side of the wedge myself.

I'm assuming that a jig wouldn't be needed to accurately remove
material equally along the length of the wedges.

* * * * If you have a flat surface on the wedge which meets the
dovetail's angles surface, you can probably simply slide that face flat
on some fine emery paper on a hard flat surface.

* * * * [ ... ]

* * * * In the place which makes it most difficult to *legally* own a
gun. :-)

OT: I've worked with guys who became police officers and some may be
retired by now. I had scored in the 90s on the test but was denied
after the physical.(Possibly because of the four pins in my knee,
which kept me out of the Navy).

When the guns laws were made more stringent the number of security
officers in New York State dropped.

* * * * When was that? *I thought that the NYC laws have been very tight
since at least about when Kennedy was assassinated.

* * * * Washington DC has been forced to relax their firearms laws
recently.

* * * * * * * * * * * * * * * * * * Businesses preferred off duty and
retired police officers because they were cheaper and legally safer.
Cheaper because there are no "middle men"(security company) involved.
And legally safer because off duty and retired cops can do a lot more
legally, and get away with a lot more legally than security guards.

So the ironic thing is that the police officers who make much more,
have more benefits, a competent union, and a pension (that is more
than I make working) are also taking away security guard positions
from armed guards when they are not on the clock.

On Jun 25, 12:10*am, "DoN. Nichols" wrote:
On 2010-06-25, Searcher7 wrote:

On Jun 24, 1:12 am, "DoN. Nichols" wrote:
On 2010-06-24, Searcher7 wrote:

* * * * [ ... ]





It looks like this whole thing must be re-thought. I had been thinking
of the black part as the base and can believe I didn't think of
something before. IT is actually the fron when screwed intot he silver
body. And the collet fits in it nicely.
http://s290.photobucket.com/albums/l.../Tools/?action....

* * * * O.K. *That is *good*. *you only need access to the back to
change collets. *The large black ring is used to close the collets onto
the workpiece, and it is in front so you don't have to work between
jaws.

I can then screw the ring on at the rear.
http://s290.photobucket.com/albums/l.../Tools/?action....

So obviously this was not made for a normal lathe set-up, and the
black front is obviously how it is supposed to be secured in whatever
machine it is supposed to be used.

* * * * Absolutely not! *The black front is what is adjusted to close or
open the collets. *It is *not* for mounting the thing to something else.

* * * * And -- it has an advantage over normal collet chucks. *Normally
the collet is drawn back in the process of closing the collet, and
slightly different diameters are drawn back differing amounts. *With
*this* one, the collet is held at a constant depth and the closing taper
moves towards the tailstock to close the collet.

Ok. Understood. But that brings up a possible issue I'll mention
below.

* * * * O.K.

* * * * [ ... ]

* * * * I can see it being held in a large collet in a really large
lathe.

I assume that such a lathe would have the option of using a variety of
these collets with different standards along with 5C.

* * * * Such a lathe would have (if any) a very large collet -- useful
for large diameter workpieces at slow spindle speeds. *they typically
don't have very fast maximum spindle speeds, as those can cause a big
chuck to "grenade". *Each chuck should have a maximum speed rating,
though small ones are likely to not have it marked.

I can also see it being used in a fixture to hold workpieces in
a mill.

I'd like to see a picture/video of such a fixture. :-)

* * * * Well ... there are dozens of possibilities depending on what is
being held and machined.

There, one of the threaded holes would get a short bar screwed
into it with a large ball handle on the end for tightening and
loosening. *(Not when using it in a rotating chuck of course, because
the handle would unbalance things -- unless you had three identical
handles screwed in at 120 degree intervals.

Actually, that would be four at 90 degrees.

* * * * Oh -- eight holes total, not the six I thought there were? *I
never had a view which made it truly clear.

Yes, eight. Every other hole is threaded.

* * * * The small bar I still think might be used to turn the small ring
onto the end of the collet and back off.

There is no place for the small bar. The ring that threads onto the
rear of the collet is solid, and actually threads about halfway on
before it bottoms out.(But I assume that is enough).

* * * * The small ring has a series of depressions around the OD. *If
the spacing between that and the wall surrounding it is just right, the
pin on one end could be slid into a depression and used to chase it
around with the outer wall keeping it engaged.

The small ring is knurled, but that is all. Nevertheless, I can thread
it onto the rear of the collet with my fingers. But like I said it
will bottom out when it is approximately halfway on.

So I'd have to create an adapter that secures this chuck *at the
front*, while also creating a seat for it at the rear.

* * * * No! *You would create an adaptor which mounts on the spindle
nose which has a cylindrical bore which is a slip fit for the OD of the
device, is deep enough to hold the body, but to leave the large black
ring accessible, and with a thin slot along the length of the bore and
some means of compressing it to hold the body.

Like a large collet or split bushing I assume. (Since the body of the
collet chuck is 2.75" long that would be a deep seat).

* * * * Yes -- except that the bushing would mount directly on the
spindle nose instead of through an adaptor.

Thinking about the material, thickness, and shape of this bushing, if
would appear that it would have to be made up of two main parts.

* * * * Toss those ideas. *The threaded holes are *not* for mounting it,
they are for rods to turn the large black ring to tighten the collet and
loosen it. *The smooth holes used when in a lathe chuck type setup with
the large bar slid in to turn it and removed before spinning the
spindle. *The threaded holes for a ball-ended bar for opening and
closing it when it is mounted in a mill.

Ok, the small ring is to secure the collet, and the large front part
of the collet chuck is to secure the work in the collet.

* * * * Yes.

So here is the problem. What is to keep the front of the collet chuck
from rotating clockwise relative to the body under cutting forces,
which would result in opening the collet.(And making things really
exciting). :-)

* * * * Well ... normally the anti-rotation pin is not expected to
handle much torque -- but here it might have to.

* * * * Can you verify which direction of rotation closes the collet
(moves the large black ring away from the body)? *Is it left-hand thread
or right-hand thread? *If it is a left-hand thread, the cutting forces
would *tighten* it, thus preventing your problem.

Turning it clockwise will screw it onto the body. But I can understand
what you're saying. (I'm probably just worried too much).

* * * * If not -- then it is likely intended to hold a workpiece on a
surface grinder or other low force operation.

* * * * [ ... ]

* * * * Again -- forget it. *You're thinking of the large black ring the
wrong way. *It *has* to be free to turn so you can loosen and tighten
the collets.

But how does one keep it from turning under cutting forces?

* * * * Pray that the anti-rotation pin works? *Look for a place where
the small pin slides into to prevent it from turning? *Add provisions
for clamping the ring to the sleeve which holds the body? *Run your
lathe spindle in reverse? *(I think that is not an option on your lathe
anyway.)

Yes, reverse is an option. But I think that this would probably be
secure enough either way. Especially since it was no doubt made for a
more powerful machine than I have.

So it comes down to this. Should I proceed with this collet chuck or
concentrate on the idea at this link: http://www.sc-c.com/metallathe/MLA21.html
(The MLA-21 would seem to be the best way to go).

And instead of using the ring at the rear of the chuck, I'd use a
drawtube, if I can modify the machine to use a modified 5C spindle.
(Just throwing out ideas). :-)

* * * * You can't make your current machine have a large enough through
diameter to work that way. *For a 5C collet closer, you need at least a
1-3/8" through bore, not your near 3/4".

Yes. That is why I am investigating installing a 5C spindle. I just
may have to shorten a drawtube shortening one. And the worse case
scenario would be a need for a different set of gears, if I can't
enlarge the center hole of the existing ones that directly drive the
spindle the spindle.

Of course I'll have to open up the headstock so I can see and measure
what is possible.

* * * * I expect that you will find that the entire OD of the spindle is
smaller than the needed bore through the spindle for a 5C collet closer.

This is why the idea is to replace the existing MT3 spindle with a 5C
spindle

Without actually going down and measuring, I think that the OD of the
bearings on my Clausing 12x24" with a 1-3/8" spindle bore is on the
order of 5" -- which I think is larger than the dimensions of your
headstock in the area where the bearings live.

I'm sure *everything* is bigger on your Clausing than on my mini-
lathe. :-) (Including the bearings).

One possibility is that you could file or sand off some of the
mating surface where the wedge slides against the dovetail. Or if there
is a chip or a burr in there, that could explain the fit problem -- it
would force the dovetail to be too wide.

I assume you mean the filing/sanding the wedge itself, correct? And
wouldn't that put more play into the assembly.

* * * * Yes -- but it does not matter -- the wedge is trapped between
the angled surface on the post body's dovetail and the inside of the
holder's dovetail. *A little play there won't hurt when you have holders
which will not fit onto the post. *And it will not be as critical a
surface as the dovetail itself.

And the wedges are more replaceable than the toolpost body. :-)

* * * * They would cost less -- if you could find a place to buy them
separate from the toolpost.

Making new ones would probably be easier. (After all, I have the
templates). :-)

* * * * But I think that they would be easier to file or sand down in the
critical area.

How about emery paper on the edge of a glass plate? (Or perhaps I can
use this item I won on eBay: 330442158063)

How are you going to maintain the *angle* of the dovetail? That
is important to the proper gripping.

I guess I could think up a jig or some sort.

* * * * Perhaps -- but I would go for the side of the wedge myself.

I'm assuming that a jig wouldn't be needed to accurately remove
material equally along the length of the wedges.

* * * * If you have a flat surface on the wedge which meets the
dovetail's angles surface, you can probably simply slide that face flat
on some fine emery paper on a hard flat surface.

Yes, that's the plan.

* * * * In the place which makes it most difficult to *legally* own a
gun. :-)

OT: I've worked with guys who became police officers and some may be
retired by now. I had scored in the 90s on the test but was denied
after the physical.(Possibly because of the four pins in my knee,
which kept me out of the Navy).

When the guns laws were made more stringent the number of security
officers in New York State dropped.

* * * * When was that? *I thought that the NYC laws have been very tight
since at least about when Kennedy was assassinated.

OT: Sometimes it's more a change in enforcement than changes in the
penal code. But the laws I was referring to mostly involve the issuing
and maintenance of carry guard licenses. For one thing a 47 hour
course is now required inititally, along with the 8 hour annual
"refresher" course.

* * * * Washington DC has been forced to relax their firearms laws
recently.

* * * * * * * * * * * * * * * * * * Businesses preferred off duty and
retired police officers because they were cheaper and legally safer.
Cheaper because there are no "middle men"(security company) involved.
And legally safer because off duty and retired cops can do a lot more
legally, and get away with a lot more legally than security guards.

So the ironic thing is that the police officers who make much more,
have more benefits, a competent union, and a pension (that is more
than I make working) are also taking away security guard positions
from armed guards when they are not on the clock.

* * * * Until something happens which needs the force working overtime,
leaving a lot of places without guards. :-)

That's happened already... But it obviously won't be a big concern of
the businesses who hire them. Especially since such an event would
close businesses anyway.

[ ... Blake Coax indicator ... ]

And they want $90 for a used one: 110548805095 :-(

Depends on your luck. And there are import versions which might
show up on eBay for a lot less than a genuine Blake.

I assume like this: 400127581321

Yes -- that shows you a top price for a new one (I think).

So I'll have to be patient.(Beside equipment for tramming is a bigger
priority at the moment).

Actually -- it is also useful for tramming the mill column, and
for adjusting the lathe tailstock offset back to zero -- or checking if
it is still at zero. :-)

Then I guess that is all I'd need for those purposes.

* * * * Yes -- as long as there is room between the spindle and the
workpiece. *Sometimes things are just too crowded for a Blake.

Thanks. Tramming is the priority. I can use other ways to measure the
workpiece on the table.

* * * * O.K. *One thing to keep your eyes open for is a fairly large
diameter outer race for a tapered roller bearing -- one about as large
in diameter as the width of the table. *You roughly center that under
the spindle, and run the feeler of the Blake around on that. *That way,
you don't have the problem of the feeler dropping into the T-slots every
so many degrees.

Ok. I'm sure that would make more sense to me once I learn how to
tram. :-)

* * * * Oh yes -- a Blake can be turned under power -- but only up to a
certainly rather slow limit. *My lathe, with a 55 RPM minimum speed is
well within that. *No bets on yours, so you would have to turn the
spindle by hand. *Same is likely for the mill.

My lathe is variable between 100 and 3,000 rpm.

These are all of the *largest* eBay vises I could use:

380087874872
300373085985
280518320722
230486712282

* * * * O.K. *Nominally 3" chucks. *I kind of like the first two more,
for various reasons. *But is the second one a shars? *And they are the
makers/importers of the troublesome toolpost?

Actually I found the invoice. The tool post I have was gotten from
800watt.(And they are notorious for having bad customer service).

* * * * O.K.

* * * * Just as a point of information, MSC's price for the AXA
(Series-100) size toolpost alone is *$211.02 when not on sale.

That's why I wait for those specials. :-)

And from what I know pick-up is allowed.(Unless what youorder is
coming from another location).

* * * * There is no storefront which I can walk up to here, but I
believe that you can phone in an order to be picked up at the storefront.

On Fri, 25 Jun 2010 23:50:05 +0000, DoN. Nichols wrote:
On 2010-06-25, James Waldby wrote:
....
Reverse rotation is a standard feature on Sieg 7x10/12/14 minilathes.
In first picture* at http://www.mini-lathe.com/Features/features.htm

Hmm ... one minor problems with the URL above.

You left out the second "Mini_Lathe" in the url. It should be
like this:

http://www.mini-lathe.com/Mini_lathe/Features/features.htm

I inserted a reference to http://www.mini-lathe.com/ first, and evidently
didn't cut and paste properly when I changed it to refer to features page.

three controls are visible above the words "Mini Lathe" -- a bat-handle
3-position toggle switch for motor Forward/Off/Reverse, a Power On/Off
rocker switch, and the speed pot. The 4th and 6th pictures**, about
halfway thru the file, show the Forward/Neutral/Reverse gear lever that
controls leadscrew rotation relative to spindle rotation. (The next
picture after that shows the bolt holes in the nose of the spindle and
the thru-spindle hole.)

O.K. That gives me a better feel for how this lathe is set up.

Thanks.

* Also http://www.mini-lathe.com/Mini_lathe/features/Controls_y.jpg,
the 4th-from-last picture, has a clearer view of the switches and pot.
Boxed RPM numbers apply when High/Low lever is in Low.

Is the gearing in that all metal, or are the gears in part
plastic?

The leadscrew drive train has plastic gears, driven by a steel ring gear on
the spindle end. See pictures at next two links, from pages at latter two.
http://www.mini-lathe.com/mini_lathe/features/Gears_y.jpg
http://www.mini-lathe.com/mini_lathe/reviews/homier2/gears.jpg
http://www.mini-lathe.com/mini_lathe/features/features_2.htm
http://www.mini-lathe.com/mini_lathe/reviews/homier2/homier.htm

The spindle drive train also has some plastic gears in it; eg see
http://www.thms.tedatum.com/shop22.html which has numerous pictures
in a description of replacing the plastic gears with steel gears from
https://thehobbyistmachinestore.com/store/, a place that also has
a steel "Mini-Mill R8 Gear Set" for about $50, should Searcher7 need
to replace or fix a gear in a drill/mill of that sort.

Awkward location for those levers.
** http://www.mini-lathe.com/Mini_lathe/features/Levers_y.jpg

Yes, they are on the back of the lathe. Besides that, the leadscrew
direction lever is difficult to operate properly because of shallow
detents in the pot metal case, and overly stiff spring. However, most
projects don't require frequent shifting of these levers.

Looking at the motor control panel, I see a screw with a stack
of nuts at the upper left -- looking sort of like a terminal post for
multiple ring terminals to attach to -- perhaps as safety grounds?

No, that's a change the page author made, to store several 10mm nuts.
http://www.mini-lathe.com/Mini_lathe/Modifications/modifications.htm#nut_keeper

--
jiw

On Jun 19, 6:55*pm, Jim Wilkins wrote:
On Jun 19, 4:31*pm, Searcher7 wrote:

On Jun 19, 3:13*pm, Jim Wilkins wrote:
On Jun 19, 11:25*am, Searcher7 wrote:

On Jun 17, 7:43*am, Jim Wilkins wrote:
On Jun 17, 1:46*am, Searcher7 wrote:
On Jun 16, 6:53 pm, "DoN. Nichols" wrote:
...
...Deflection controls the maximum length you can have protruding
from the chuck or collet. The part inside the spindle is irrelevant.

I thought that the distance between tailstock and headstock would
determine this.

For 2" pipe and light cuts perhaps. 1/8" brass rod yields too much to
turn straight if it protrudes even 1/2".

And I assume deflection is why steady rests were made.

It is, but they can't occupy the same space as the carriage. Follower
rests don't help if the part has shoulders. If you tried to turn a 6"
length of 1/4" aluminum without the tailstock it would just climb up
onto the lathe bit.

Of course. (But I don't know what you mean by shoulders).

Yes. My determination is that with my lathe 9/16" would be the maximum
diameter I could pass through the spindle using 3C collets, because
that is the largest diameter these collets are made for.

Higher than that would require a 5C collet chuck for the 5C collets.

Not if you needed to turn some 3/4" thin walled brass tubing, or thin
a washer, or remove the part to test a fit and then replace it to cut
some more, or turn it around to machine the other end, or file it
without risking precious body parts, or face a batch of pieces to the
same length. An MT3 collet would be fine for all those.

But Isn't MT3 a "tool holding" collet?

You could make one end of the drawbar serve as the depth stop by
turning it down below the thread roots. I'd bring it out within ~1/2"
of the end. The collet slides further into the spindle as you tighten
it but the drawbar doesn't move.

It also helps if you are making bicycle spokes or threading the ends
of tubing, ...
Of course. But I have no projects like that on the horizon yet.

They aren't on the horizon, they are submarines waiting to torpedo you
with broken lamp and plumbing parts etc. When I *bought the lathe I
had no idea that in a few years I would be making antique lawnmower
tires and space laser prototypes on it

MT3 collets use a drawbar, so they are not an option.
Darren Harris

Ask yourself why they are used on rotary tables. An MT2 collet holds
the centering rod hehttp://picasaweb.google.com/KB1DAL/H...10360947850418

But wouldn't an MT2 dead center be better?

On the lathe you could do the same to center a gear blank on a
faceplate, I did (with 5C) to turn the OD of that piece. A chuck and
faceplate won't fit at the same time, but you can use a collet with
either, like to hold a depth stop for a chuck.

I'd think to use my MT2 dead center here also. And I'd have to make
sure that I get a chuck or a face plate with large enough center
bores.

Thanks.

Darren Harris
Staten Island, New York.

On Jun 26, 2:27*pm, Searcher7 wrote:
On Jun 19, 6:55*pm, Jim Wilkins wrote:
...

And I assume deflection is why steady rests were made.

...Follower
rests don't help if the part has shoulders. If you tried to turn a 6"
length of 1/4" aluminum without the tailstock it would just climb up
onto the lathe bit.

Of course. (But I don't know what you mean by shoulders).

Changes in diameter. The gauge with all the different threads has
shoulders or steps between sizes. It's too short for a steady rest and
a follower rest would hit or fall off the steps even if they weren't
too rough. IIRC I threaded the first half with it held in a collet,
then tightened a nut on one of the threads for a lathe dog and
threaded the second half between centers.


Yes. My determination is that with my lathe 9/16" would be the maximum
diameter I could pass through the spindle using 3C collets, because
that is the largest diameter these collets are made for.

Higher than that would require a 5C collet chuck for the 5C collets.

Not if you needed to turn some 3/4" thin walled brass tubing, or thin
a washer, or remove the part to test a fit and then replace it to cut
some more, or turn it around to machine the other end, or file it
without risking precious body parts, or face a batch of pieces to the
same length. An MT3 collet would be fine for all those.

But Isn't MT3 a "tool holding" collet?

We don't have Purity Police in NH. It's a "something round holding"
collet. If that something is long it belongs in a hollow work holding
collet, if short either will do. They both grip well enough to
withstand the forces of cutting metal. If you want to be an inventor +
machinist, look beyond what things are "meant" to do.

Ask yourself why they are used on rotary tables. An MT2 collet holds
the centering rod he
http://picasaweb.google.com/KB1DAL/H...10360947850418

But wouldn't an MT2 dead center be better?

A pointed dead center wouldn't have held the blank while I slid the
parallels into place and tightened the bolts. Faceplate setups are
awkward. Theoretically a dead center might give better centering
accuracy IF the hole wasn't burred or unevenly countersunk, but this
is only the steering gear for a garden tractor.

In this case the blank would be located by too many points unless the
center is spring loaded, and then you couldn't tell if the blank
shifted and pushed the center inward when the bolts were tightened.

These are $309 in Enco's latest flyer:
http://www.kalamazooind.com/products...re-for-chucks/

I think the right place for 5C collets is in the spindle of a lathe
meant for them, but you could clamp that in a 4-jaw.

jsw

On 2010-06-26, Searcher7 wrote:
On Jun 25, 12:10*am, "DoN. Nichols" wrote:
On 2010-06-25, Searcher7 wrote:

[ ... ]

There, one of the threaded holes would get a short bar screwed
into it with a large ball handle on the end for tightening and
loosening. *(Not when using it in a rotating chuck of course, because
the handle would unbalance things -- unless you had three identical
handles screwed in at 120 degree intervals.

Actually, that would be four at 90 degrees.

* * * * Oh -- eight holes total, not the six I thought there were? *I
never had a view which made it truly clear.

Yes, eight. Every other hole is threaded.

O.K. I knew that every other hole was threaded, but I somehow
thought that there were a total of six holes, not eight.

* * * * The small bar I still think might be used to turn the small ring
onto the end of the collet and back off.

There is no place for the small bar. The ring that threads onto the
rear of the collet is solid, and actually threads about halfway on
before it bottoms out.(But I assume that is enough).

* * * * The small ring has a series of depressions around the OD. *If
the spacing between that and the wall surrounding it is just right, the
pin on one end could be slid into a depression and used to chase it
around with the outer wall keeping it engaged.

The small ring is knurled, but that is all.

But is it knurled deep enough to allow the pin on the end of the
small rod to act to spin it on or off?

Nevertheless, I can thread
it onto the rear of the collet with my fingers. But like I said it
will bottom out when it is approximately halfway on.

Sure -- you could probably thread it on a little more if you
were pressing in the collet nose while installing the ring, but that
would limit the size range of the collet.

[ ... ]

* * * * No! *You would create an adaptor which mounts on the spindle
nose which has a cylindrical bore which is a slip fit for the OD of the
device, is deep enough to hold the body, but to leave the large black
ring accessible, and with a thin slot along the length of the bore and
some means of compressing it to hold the body.

Like a large collet or split bushing I assume. (Since the body of the
collet chuck is 2.75" long that would be a deep seat).

* * * * Yes -- except that the bushing would mount directly on the
spindle nose instead of through an adaptor.

Thinking about the material, thickness, and shape of this bushing, if
would appear that it would have to be made up of two main parts.

I see it as only two parts -- a cylinder perhaps an inch larger
in diameter than the holder body, and a screw threaded in to close the
slot. (Oh yes -- also the studs to mount it on the spindle nose and the
corresponding nuts. :-)

But it will need a tricky bit of work to cut the slit along one
size to allow the screw to clamp it onto the body. You'll need the mill
and some way to mount the rather large piece of metal to do that.

[ ... ]

So here is the problem. What is to keep the front of the collet chuck
from rotating clockwise relative to the body under cutting forces,
which would result in opening the collet.(And making things really
exciting). :-)

* * * * Well ... normally the anti-rotation pin is not expected to
handle much torque -- but here it might have to.

* * * * Can you verify which direction of rotation closes the collet
(moves the large black ring away from the body)? *Is it left-hand thread
or right-hand thread? *If it is a left-hand thread, the cutting forces
would *tighten* it, thus preventing your problem.

Turning it clockwise will screw it onto the body.

So turning forces would normally loosen it.

But I can understand
what you're saying. (I'm probably just worried too much).

I think that within the normal size range of the collets, it
would work. If you went to one of the pot chucks that would be a
different matter.

* * * * If not -- then it is likely intended to hold a workpiece on a
surface grinder or other low force operation.

* * * * [ ... ]

* * * * Again -- forget it. *You're thinking of the large black ring the
wrong way. *It *has* to be free to turn so you can loosen and tighten
the collets.

But how does one keep it from turning under cutting forces?

* * * * Pray that the anti-rotation pin works? *Look for a place where
the small pin slides into to prevent it from turning? *Add provisions
for clamping the ring to the sleeve which holds the body? *Run your
lathe spindle in reverse? *(I think that is not an option on your lathe
anyway.)

Yes, reverse is an option. But I think that this would probably be
secure enough either way. Especially since it was no doubt made for a
more powerful machine than I have.

Certainly for the size range of 0.750" on down I see no problem.
Light cuts up to the 1.125" maximum should work as well.

So it comes down to this. Should I proceed with this collet chuck or
concentrate on the idea at this link: http://www.sc-c.com/metallathe/MLA21.html
(The MLA-21 would seem to be the best way to go).

I agree that the MLA-21 would be the better choice. What
remains to be seen is how difficult the machining is to make it from the
castings.

Why not buy the drawing first to see what you will have to do.
The "lathe only" construction suggests that the side clearance holes for
the tommy bar access to the ring would be part of the casting -- though
a mill and a dividing head might be used to dress up the edges a bit.

Checking -- yes you still get partial credit for the drawings
which you purchased if you order them first, and the casting kit without
the drawings later.

One of the things which I consider best about this is that you
can mark the spindle and the casting where they join prior to turning
the closing taper and bore for the collet, so you will get the best
repeatability.

And instead of using the ring at the rear of the chuck, I'd use a
drawtube, if I can modify the machine to use a modified 5C spindle.
(Just throwing out ideas). :-)

* * * * You can't make your current machine have a large enough through
diameter to work that way. *For a 5C collet closer, you need at least a
1-3/8" through bore, not your near 3/4".

Yes. That is why I am investigating installing a 5C spindle. I just
may have to shorten a drawtube shortening one. And the worse case
scenario would be a need for a different set of gears, if I can't
enlarge the center hole of the existing ones that directly drive the
spindle the spindle.

Of course I'll have to open up the headstock so I can see and measure
what is possible.

* * * * I expect that you will find that the entire OD of the spindle is
smaller than the needed bore through the spindle for a 5C collet closer.

This is why the idea is to replace the existing MT3 spindle with a 5C
spindle

What I am trying to say is that there is not enough metal in the
headstock to hold a large enough spindle (and the bearings) to accept 5C
collets.

Typically, everything else has to be scaled up when you scale up
the ID of the spindle. Multiply the size of *everything* by 1.83,
including the spacing of front bed way from the rear.

You have bearings at each end of the spindle, you have a gear
setup to switch speeds. You *may* have a belt pulley in the headstock
as well. (I did not see photos of the interior.) All of these things
have to be increased in size by the same ratio.

If you tried to increase the diameter of the spindle without
increasing the size of the headstock casting, you would have to use
thinner bearings -- which would not be strong enough to handle the
cutting loads.

For comparison -- the spindle for my 12x24" lathe (made to
accept 5C collets with an adaptor) has an OD of 2.000" at the chuck end
bearing mount, and an OD of 1.875". Look for tapered roller bearings
which accept those sizes on their ID, and see how small an OD for the
outer bearing race can be found. The compare that to the size of your
headstock casting.

Without actually going down and measuring, I think that the OD of the
bearings on my Clausing 12x24" with a 1-3/8" spindle bore is on the
order of 5" -- which I think is larger than the dimensions of your
headstock in the area where the bearings live.

I'm sure *everything* is bigger on your Clausing than on my mini-
lathe. :-) (Including the bearings).

That is why it can accept 5C collets in a spindle adaptor -- it
is big enough. Yours is *not* If you want to handle 5C collets, plan on
at least a 10" lathe -- which you will probably have to strip down to
components and carry them up one at a time.

I believe that even the South Bend "Heavy 10" woll not handle
the 5C collets in the spindle -- just the 12" swing or larger.

[ ... ]

* * * * Yes -- but it does not matter -- the wedge is trapped between
the angled surface on the post body's dovetail and the inside of the
holder's dovetail. *A little play there won't hurt when you have holders
which will not fit onto the post. *And it will not be as critical a
surface as the dovetail itself.

And the wedges are more replaceable than the toolpost body. :-)

* * * * They would cost less -- if you could find a place to buy them
separate from the toolpost.

Making new ones would probably be easier. (After all, I have the
templates). :-)

If you are up to cutting a three-start internal thread on an interrupted
cut. And look at the complexity of the other parts of the wedge. You
have to make some of those to use for fixturing while you cut the
threads.

* * * * But I think that they would be easier to file or sand down in the
critical area.

How about emery paper on the edge of a glass plate? (Or perhaps I can
use this item I won on eBay: 330442158063)

Hmm ... depends on the quality of the surface plate. He says
that he checked it flat with a square. :-) To *really* check it, you
need a setup with a micro-inch reading sensor traveling on arms
supported above the surface. The lowest grade should be flat within
0.000050" (50 micro-inches), and as the grade goes up, the number of
allowed micro-inches of deviation go down. There is no way you are
going to check that with a square. :-)

But if it is not sufficiently accurate, it should work fine for
your task. (Be sure to keep the abrasive grit from getting on the
surface anyway.)

A piece of glass perhaps 1/4" or 3/8" thick should suffice for
the purpose of adjusting the wedge. Remember to keep trying it
frequently for fit, or you could get too small.

[ ... ]

I'm assuming that a jig wouldn't be needed to accurately remove
material equally along the length of the wedges.

* * * * If you have a flat surface on the wedge which meets the
dovetail's angles surface, you can probably simply slide that face flat
on some fine emery paper on a hard flat surface.

Yes, that's the plan.

I would still go for tuning the gap in the wedge myself. Or --
sell it on eBay and get a better one.

BTW There has been a discussion of Shars tools on the local
metalworking mailing list, and the general opinion is that
they are very good -- with specific good reports on the
clone of the Kurt vises.

[ ... ]

* * * * Until something happens which needs the force working overtime,
leaving a lot of places without guards. :-)

That's happened already... But it obviously won't be a big concern of
the businesses who hire them. Especially since such an event would
close businesses anyway.

Which means that people could consider warehouses easier to
burglarize.

[ ... Blake Coax indicator ... ]

[ ... ]

* * * * Yes -- as long as there is room between the spindle and the
workpiece. *Sometimes things are just too crowded for a Blake.

Thanks. Tramming is the priority. I can use other ways to measure the
workpiece on the table.

* * * * O.K. *One thing to keep your eyes open for is a fairly large
diameter outer race for a tapered roller bearing -- one about as large
in diameter as the width of the table. *You roughly center that under
the spindle, and run the feeler of the Blake around on that. *That way,
you don't have the problem of the feeler dropping into the T-slots every
so many degrees.

Ok. I'm sure that would make more sense to me once I learn how to
tram. :-)

Essentially, you are rotating a feeler around the center point
of the spindle and measuring how much it goes up or down. Since the
table is interrupted by the T-slots, something of precise thickness and
ground smooth (e.g. a bearing outer race) can give a surface for the
feeler to travel over without problems.

* * * * Oh yes -- a Blake can be turned under power -- but only up to a
certainly rather slow limit. *My lathe, with a 55 RPM minimum speed is
well within that. *No bets on yours, so you would have to turn the
spindle by hand. *Same is likely for the mill.

My lathe is variable between 100 and 3,000 rpm.

O.K. Their page says:

"It is recommended that operating speed not exceed 800 RPM
approx."

so you should be fine as long as you keep it at the low end.

These are all of the *largest* eBay vises I could use:

380087874872
300373085985
280518320722
230486712282

* * * * O.K. *Nominally 3" chucks. *I kind of like the first two more,
for various reasons. *But is the second one a shars? *And they are the
makers/importers of the troublesome toolpost?

And the report from the local club says that their vise is very
good.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2010-06-26, James Waldby wrote:
On Fri, 25 Jun 2010 23:50:05 +0000, DoN. Nichols wrote:
On 2010-06-25, James Waldby wrote:
...
Reverse rotation is a standard feature on Sieg 7x10/12/14 minilathes.
In first picture* at http://www.mini-lathe.com/Features/features.htm

Hmm ... one minor problems with the URL above.

You left out the second "Mini_Lathe" in the url. It should be
like this:

http://www.mini-lathe.com/Mini_lathe/Features/features.htm

I inserted a reference to http://www.mini-lathe.com/ first, and evidently
didn't cut and paste properly when I changed it to refer to features page.

Cut and paste can be tricky -- especially if the system plays
with case. :-)

[ ... ]

Is the gearing in that all metal, or are the gears in part
plastic?

The leadscrew drive train has plastic gears, driven by a steel ring gear on
the spindle end. See pictures at next two links, from pages at latter two.

http://www.mini-lathe.com/mini_lathe/features/Gears_y.jpg
http://www.mini-lathe.com/mini_lathe/reviews/homier2/gears.jpg
http://www.mini-lathe.com/mini_lathe/features/features_2.htm
http://www.mini-lathe.com/mini_lathe/reviews/homier2/homier.htm

O.K. Useful information there.

The spindle drive train also has some plastic gears in it;

Ouch! The photos also tell me that there is no way that
Searcher7 could put in a spindle which would accept a 5C collet closer. :-)

The gears under the spindle would have to be scaled up too,
which would move the spindle higher, requiring a riser block on the
tailstock to move it to the same height, and the carriage would require
a riser block on the compound, making it that much more flexible. :-)

eg see
http://www.thms.tedatum.com/shop22.html which has numerous pictures
in a description of replacing the plastic gears with steel gears from
https://thehobbyistmachinestore.com/store/, a place that also has
a steel "Mini-Mill R8 Gear Set" for about $50, should Searcher7 need
to replace or fix a gear in a drill/mill of that sort.

Great! That will hopefully be useful for him.

Awkward location for those levers.
** http://www.mini-lathe.com/Mini_lathe/features/Levers_y.jpg

Yes, they are on the back of the lathe. Besides that, the leadscrew
direction lever is difficult to operate properly because of shallow
detents in the pot metal case, and overly stiff spring. However, most
projects don't require frequent shifting of these levers.

That depends, of course. On my 12x24" Clausing, which has
separate power feed from the threading leadscrew (derived from a keyway
milled the length of the leadscrew turning a worm gear in the carriage
apron) the tumbler needs to be set into reverse for feed towards the
headstock, and when I switch to cross-feed, it feeds out with the same
setting. This is nice when turning to a shoulder followed by facing the
shoulder (just switch from longitudinal to cross-feed), but when facing
towards center, or parting off, I need to switch the tumbler into
forward -- as well as for normal threading. So -- I wind up switching it
fairly often in making a single part.

Looking at the motor control panel, I see a screw with a stack
of nuts at the upper left -- looking sort of like a terminal post for
multiple ring terminals to attach to -- perhaps as safety grounds?

No, that's a change the page author made, to store several 10mm nuts.
http://www.mini-lathe.com/Mini_lathe/Modifications/modifications.htm#nut_keeper

O.K. I see that they are needed for the chuck mounting -- and
hopefully it is tall enough to store them *all* when a collet nosepiece
is installed.

Thanks,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2010-06-26, Searcher7 wrote:
On Jun 19, 6:55*pm, Jim Wilkins wrote:

[ ... ]

And I assume deflection is why steady rests were made.

It is, but they can't occupy the same space as the carriage. Follower
rests don't help if the part has shoulders. If you tried to turn a 6"
length of 1/4" aluminum without the tailstock it would just climb up
onto the lathe bit.

Of course. (But I don't know what you mean by shoulders).

Where you are turning some cylindrical work and you have two
diameters. That towards the chuck is say 1" diameter, and you are
turning the end down to perhaps 1/2" diameter. Given the power (or lack
thereof) of the Mini-Lathe, you can't make that reduction in a single
pass. Follower rests (which Jim specifically mentioned) ride behind and
above the workpiece and travel with the carriage. Usually, the follower
leads the cutting tool, so on the second (and subsequent) pass(es), the
follower would hit the increase in diameter (the shoulder) and
(probably) cause things to break. Sometimes, it is possible to set up
the follower to trail right behind the tool, so you don't have this
particular problem -- unless you have another shoulder to the right of
the area where you are turning.

Yes. My determination is that with my lathe 9/16" would be the maximum
diameter I could pass through the spindle using 3C collets, because
that is the largest diameter these collets are made for.

Higher than that would require a 5C collet chuck for the 5C collets.

Not if you needed to turn some 3/4" thin walled brass tubing, or thin
a washer, or remove the part to test a fit and then replace it to cut
some more, or turn it around to machine the other end, or file it
without risking precious body parts, or face a batch of pieces to the
same length. An MT3 collet would be fine for all those.

But Isn't MT3 a "tool holding" collet?

Yes. That does not mean that it can't be used for certain
limited work-holding purposes. It won't handle through-the-spindle
workpieces, which is why it is not a work-holding collet.

[ ... ]

MT3 collets use a drawbar, so they are not an option.
Darren Harris

Ask yourself why they are used on rotary tables. An MT2 collet holds
the centering rod hehttp://picasaweb.google.com/KB1DAL/H...10360947850418

But wouldn't an MT2 dead center be better?

Actually -- no. The collet is holding a cylindrical piece onto
which the workpiece slides to hold it centered prior to bolting it down
to the rotary table. It looks as though there were some extra holes
drilled and tapped in the table to improve the clamping of this
particular workpiece.

On the lathe you could do the same to center a gear blank on a
faceplate, I did (with 5C) to turn the OD of that piece. A chuck and
faceplate won't fit at the same time, but you can use a collet with
either, like to hold a depth stop for a chuck.

I'd think to use my MT2 dead center here also.

Actually -- mostly no! The dead center has a conical point. It
sticks out of the spindle by a fixed amount. Where this stops a
workpiece is going to be dependent on whether it has a center hole, and
if so, how deep it is, or how large in diameter.

With the collet, you can put in a piece of stock a little too
long and face the end to provide the proper stop depth.

And I'd have to make
sure that I get a chuck or a face plate with large enough center
bores.

Of course.

Hmm ... I wonder whether my 5C collet adaptor which has a flange
to engage the spindle protector) will fit though my chuck body. (L-00
spindle nose, FWIW. :-)

This may work better on a Hardinge, which accepts the collet
without an adaptor.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Sun, 27 Jun 2010 01:33:32 +0000, DoN. Nichols wrote:
On 2010-06-26, James Waldby wrote:
On Fri, 25 Jun 2010 23:50:05 +0000, DoN. Nichols wrote:
On 2010-06-25, James Waldby wrote:
....
http://www.mini-lathe.com/Mini_lathe/Features/features.htm
....
Is the gearing in that all metal, or are the gears in part
plastic?

The leadscrew drive train has plastic gears, driven by a steel ring
gear on the spindle end. See pictures at next two links, from pages
at latter two.
http://www.mini-lathe.com/mini_lathe/features/Gears_y.jpg
http://www.mini-lathe.com/mini_lathe/reviews/homier2/gears.jpg
http://www.mini-lathe.com/mini_lathe/features/features_2.htm
http://www.mini-lathe.com/mini_lathe/reviews/homier2/homier.htm

O.K. Useful information there.

The spindle drive train also has some plastic gears in it;

Ouch! The photos also tell me that there is no way that
Searcher7 could put in a spindle which would accept a 5C collet closer.
:-)
The gears under the spindle would have to be scaled up too,
which would move the spindle higher, requiring a riser block on the
tailstock to move it to the same height, and the carriage would require
a riser block on the compound, making it that much more flexible. :-)

Yes, time and money spent on such spindle changes probably would be better
spent on getting a bigger lathe instead. That said, the minilathe as
delivered is a reasonable and inexpensive choice for making small parts
of medium accuracy. A lot of the same parts can be made using the standard
3-jaw and optional 4-jaw chucks as when using collets, albeit at the cost
of more setup time vs less accuracy and occasional marring of parts.

....
http://www.thms.tedatum.com/shop22.html which has numerous pictures
in a description of replacing the plastic gears with steel gears from
https://thehobbyistmachinestore.com/store/, a place that also has
a steel "Mini-Mill R8 Gear Set" for about $50, should Searcher7 need to
replace or fix a gear in a drill/mill of that sort.

Great! That will hopefully be useful for him.

Awkward location for those levers.
** http://www.mini-lathe.com/Mini_lathe/features/Levers_y.jpg

Yes, they are on the back of the lathe. Besides that, the leadscrew
direction lever is difficult to operate properly because of shallow
detents in the pot metal case, and overly stiff spring. However, most
projects don't require frequent shifting of these levers.

That depends, of course. On my 12x24" Clausing, which has
separate power feed from the threading leadscrew (derived from a keyway
milled the length of the leadscrew turning a worm gear in the carriage
apron) the tumbler needs to be set into reverse for feed towards the
headstock, and when I switch to cross-feed, it feeds out with the same
setting. This is nice when turning to a shoulder followed by facing the
shoulder (just switch from longitudinal to cross-feed), but when facing
towards center, or parting off, I need to switch the tumbler into
forward -- as well as for normal threading. So -- I wind up switching
it fairly often in making a single part.

Unfortunately those considerations don't apply to the minilathe, which
has no power crossfeed, and with the leadscrew drive intended for
threading, it (as stock) doesn't have ratios low enough to get a good
finish. Ie, for a fine finish you have to crank the compound by hand,
or slowly turn the carriage handwheel, or fit a gear-motor to drive the
leadscrew (eg http://www.varmintal.com/alath.htm#Ultra_Fine) etc.

Looking at the motor control panel, I see a screw with a stack
of nuts at the upper left -- looking sort of like a terminal post for
multiple ring terminals to attach to -- perhaps as safety grounds?

No, that's a change the page author made, to store several 10mm nuts.
http://www.mini-lathe.com/Mini_lathe/Modifications/modifications.htm#nut_keeper

(Note, I should have referred to 6x1mm nuts; 10mm is wrench size.)

O.K. I see that they are needed for the chuck mounting -- and
hopefully it is tall enough to store them *all* when a collet nosepiece
is installed.

I think it makes more sense the way I do it which is to store the
nuts on the ends of the studs, with the studs loctite'd into their
holes on the backs of the chucks or the back of the face plate.

--
jiw

On Jun 26, 8:17*pm, "DoN. Nichols" wrote:
On 2010-06-26, Searcher7 wrote:
...
I'm sure *everything* is bigger on your Clausing than on my mini-
lathe. :-) (Including the bearings).

* * * * That is why it can accept 5C collets in a spindle adaptor -- it
is big enough. *Yours is *not* If you want to handle 5C collets, plan on
at least a 10" lathe -- which you will probably have to strip down to
components and carry them up one at a time.

* * * * I believe that even the South Bend "Heavy 10" woll not handle
the 5C collets in the spindle -- just the 12" swing or larger.
* * * * [ ... ]
* * * * * * * * DoN.

The South Bend Heavy 10 which is a scaled-down 13" takes 5C, the Light
10 doesn't.

In my limited R&D experience a 10" lathe with 5C collets is the
minimum really acceptable size for serious work like making machine
parts and special tools. I haven't used a 9" lathe. and smaller ones
were enough for the small aluminum parts I needed for electronics.
There have been only a few jobs I had to send out that a 12" lathe
could have done. My old belt-drive South Bend is marginal for carbide
tooling, which makes turning stainless steel difficult. South Bend
suggested it for toolroom or maintenance use, and the 9" for a
hobbyist.

The companies that needed steel parts had 15" or so lathes available.
For a home shop I Iike the 10" better only because the chucks are
light enough to handle easily and the tailstock slides smoothly with
one hand, important for drilling. I can make very small pieces on it
as easily as on a Sherline, except for drilling small deep holes where
more speed would help. I learned on a 15" lathe and if I was making
parts to someone else's requirements that's what I'd want.

The 12" Clausing is a common choice for maintenance and short runs.

jsw