On Wed, 01 Aug 2007 15:26:16 -0500, Louis Ohland
wrote:
I've been scheming how to put a real collet on my dad's red lathe
(PRC). It has a 1" bore and an MT4 spindle. Three options seem to exist:
Bison 5C collet chuck
About $300 for non-Set Tru, $100 for a 1-1/2x8 adapter plate
Plus: I can chuck a 1" barrel through it, or up to 1.125" into it.
Chuck is wrench operated
Kalamazoo 1CC collet chuck
About $300 for it, 5C fixture, use in 3 or 4 jaw chuck
Plus: Same as Bison 5C
Drawtube
Maybe $200
Minus: The drawtube cuts down the pass-through to less than an inch
3C collets only go to 1/2 inch
5C collets would take one heckuva adapter...
Comments? Derision? Disbelief?
========
As is frequently the case, more information will result in better
advice.
For example, how will you be using the collet?
Will you need to be able to chuck long rods, i.e. through the
spindle?
How frequently will you use this set up?
How much piecepart volume do you expect to run?
How important is quick set-up?
Some alternatives:
(1) clamp a block to the faceplate. Machine the block to the
size rod or bar you want to machine. Use a set screw or split the
block to clamp the part. If you drill the face plate for dowel
pins this can be quick to set-up. Use steel blocks for
durability, aluminum for non-mar.
(2) Buy a #4MT holder [a quick internet check shows a #3 is as
large as H&H goes, but adapters are cheap] and the ER collets you
need as you need them. For example see
http://hhip.com/products/product_vie...D=900-0005-061
sets in #4MT are available
http://hhip.com/products/product_vie...uctID=900-0005
(3) Buy what is called a collet vise that uses 5C collets and
bolt to the faceplate. Get an inexpensive collet set and others
[metric/square/hex] as you need them
click on
http://hhip.com/products/product_vie...ID=900-0016-21
http://hhip.com/products/product_vie...D=900-0012&p=2
http://hhip.com/products/product_vie...uctID=900-0011
http://hhip.com/products/product_vie...ID=900-0016-11
(there are also nylon collets available)
(4) buy what I have heard called a tumble block set and bolt to
the lathe faceplate with an angle iron. I have done this and set
up is time consuming. Benefit is that stock can go through the
collet and into the headstock, and you get another very nice
tool. Get both the hex and square blocks.
http://hhip.com/products/product_vie...ID=900-0016-20
I did this and it works fine, and you get a tool/fixture you can
use for other things. (You will need 5C collets)
Note that if you have a piece of 1/2 drill rod or round tool
steel you can clamp in the tailstock chuck and tighten either the
tumble blocks or collet vise to the rod and then fasten the
tumble block/vise to the face plate. This will get you within a
few thousandths, or at least as good as a standard 3-jaw chuck.
Good luck and let the group know how you make out.
Unka' George [George McDuffee]
============
Merchants have no country.
The mere spot they stand on
does not constitute so strong an attachment
as that from which they draw their gains.
Thomas Jefferson (1743-1826),
U.S. president. Letter, 17 March 1814.