Holding small parts in a large lathe chuck

[jjr2001]

My 5" six jaw lathe chuck has a minimum capacity of 3/8".
When I need to hold smaller pieces in it I simply use a spare
ER20 arbor and collet. Works well and the imports can be
serviceable with a bit of selection.

Cheers, JR

[mklotz]

Folks who don't yet have a collet arbor as pictured but do have a hexagonal collet block, typically for 5C collets, can use that as well. Lacking that, another dodge is to make a short arbor for a Jacobs chuck and grasp that in the lathe chuck.

[jjr2001]

Thanks Marv, part of the fun in working in the shop is that there are usually many ways to get the job done.

Cheers, JR

[DIYer]

Thanks jjr2001! We've added your Small Part Holding Method to our Workholding category,
as well as to your builder page: jjr2001's Homemade Tools. Your receipt:

Small Part Holding Method by jjr2001

tags: arbor, collet

[Paul Jones]

Thanks Marv,

I have been wanting to make a 5C collet holder for my lathe. My work around has been like the one by JR using a 0.0001" TIR high precision Techniks ER32 collet chuck (see http://www.homemadetools.net/forum/e...aw-chuck-65548 ) but the 5C collets have a wider diameter range.

However, I have owned a hexagonal collet block for 5C collets for years and just never considered putting it into the lathe chuck. That is a great solution and thank you for the advice.

Thank you,

Paul

[scrdmgl]

Hi JR: Depending on the degree of accuracy, needed or expected on the part to be machined, by holding any type of chuck or holding device, you're relying on the lathe chuck plus the second device to hold a tolerance. Remember this, you're best center line is the one provided by your lathe spindle. By stacking up component over component, you're adding up their built in deviation to the part being held. Given the size of your lathe I figure the your spindle must be a MT3 size. MT chucks of ER type, are offered in ER40 (maximum size commonly available) or ER32 if so you wish, that can be found in the web for affordable prices unless you decide to go for high end chucks of the same type which are also available. One vendor that offers good quality ER chucks in many variations at good prices, is CTC Tools who has reasonable shipping rates to North America and elsewhere. I'm satisfied with their products for price and quality, check them out. The above recommendation applies only if you're working at high or maximum accuracy, otherwise don't bother. However, my working philosophy is never to sell yourself short on quality and precision if possible.

Regards

Jorge

[jjr2001]

Thanks for the heads up on the CTC tools. They seem to have a good inventory of ER collets and everything else!
Right on about the stacking of chucks and tolerances. I also have a 4 jaw chuck when I need to be as close as possible
to a dimension or turn on centers. I Just use the "chuck in a chuck" for a quick solution.

Cheers, JR