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.