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.
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