PDA

View Full Version : 5C Collett Chuck



wbleeker
08-20-2010, 02:48 AM
A while back I bought one of these along with a D1-6 camlock backing plate, I machined an adaptor plate to fit between the two with very neat spigots. On putting an indicator on the chuck I found I had about three thou runout, a mate of mine got one at the same time and just machined his spigot smaller and set the chuck up with an indicator to get it true, but I think grinding the chuck out in situ might be the better way to go, has anyone had any experience doing this?
Will

oldtiffie
08-20-2010, 07:17 AM
Will.

I have a similar ER-32 collect holder for my lathe and mill. It works very well. Mine is a bolt-on and not a D1-6 cam-lock as yours is but is otherwise the same principle.

I think your friend is correct.

I allowed about say 0.003">0.005" (~ 0.12>0.20mm) diameter clearance on the spigot bore. I loosen the securing bolts and use it as a "poor mans" "tap-true".

I have a bit of stuff to suit the particular collet, tighten it and then rotate it under a good Test Dial Indicator (0.01mm/0.0005") and tap the collet adaptor with a 1 1/2" diameter x say 4" long bit of phosphor-bronze which I use as "dolly" and "dead-blow" hammer. As soon as the TDI registers minimum total indicator run-out I tighten the bolts and re-check.

This will by-pass/neutralise any radial off-set (ie "run-out") between the inner and outer tapers of the collet as well as any run-out between the adaptor taper and the lathe head-stock axis.

All collets and adaptors have tolerance for angular misalignment (causes a "conical" run-out) but this procedure will not counter that. It should be so small that it won't matter most times.

It will really enable you to use or allow for less than perfect adaptors and collets.

I found that with mine, that once I had it set for one collet it was pretty well OK for most other jobs in most other collets with the adaptor at that "set true" setting.

"Out of balance" is not an issue either as it is insignificant.

It only takes about 2>5 minutes to set up.

It works a treat on 3-jaw chucks too as a "3 thou out" chuck is soon "fixed".

My next time will not be the first time I've used it on a 4-jaw chuck either.

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/AirSmith03.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/AirSmith01-1.jpg

And on the mill:
http://i200.photobucket.com/albums/aa294/oldtiffie/HF-45%20Mill%20misc/HF45-4-1.jpg

Just put it on your rotary table, put an indicator on the job, spin the rotary table, "tap it true" and the job in the collet is concentric with the rotary table - no "adaptors" or "locators" needed. Next, put the indicator in the mill spindle and spin it slowly and adjust the "X" and "Y" slides until there is minimal indicated run-out and the job, the rotary table and spindle axis are all aligned and concentric.

I hope it helps.

deltaenterprizes
08-20-2010, 10:51 AM
The cheapie 5C collet chuck I bought was out 2-3 thou with the OD so I trued the OD and took a light cut on the ID and it works great within .0005''.
I also have to "adjust true" like in the above post sometimes.

wbleeker
08-20-2010, 06:26 PM
Thanks for the replies Tiffie and Delta, Delta did you just skim it in the lathe or did you grind it?
Will

rmuell01
08-20-2010, 09:47 PM
A while back I bought one of these along with a D1-6 camlock backing plate, I machined an adaptor plate to fit between the two with very neat spigots. On putting an indicator on the chuck I found I had about three thou runout, a mate of mine got one at the same time and just machined his spigot smaller and set the chuck up with an indicator to get it true, but I think grinding the chuck out in situ might be the better way to go, has anyone had any experience doing this?
Will

What's a spigot???:confused:

oldtiffie
08-21-2010, 01:02 AM
A spigot is generally a "male" part that "mates" with or locates in a "female" part.

On most non-screwed lathe head-stock spindle flanges there is a round protruding "spigot" that the "female" (on the adaptor) is located on.

For a good idea of it - at Littlemachineshop.com:
http://www.littlemachineshop.com/Products/products.php

and go to lathe chucks>adaptors

and/or search for item #: 2961

http://www.google.com.au/#hl=en&q=spigot+bearing&revid=1385391853&sa=X&ei=P1tvTKyFJ4XSuQP09ulB&ved=0CFYQ1QIoAA&fp=65c15ffa92ed0752