Need to spin lights and parts...

[donn_]

I'm looking for a creative way to spin flashlight parts, using either an electric drill or Foredom handpiece locked into a vise. I need to do this for the purpose of polishing the parts.

I've tried threaded rod with washers and locking nuts at each end of the part, and then chucked into the tool, but it's a royal pain to get it all centered enough to spin smoothly.

When I get workshop space, I'll buy a mini-lathe, but in the meantime, any good ideas for accomplishing this task would be appreciated.

 

[will]

You might be able to use your set up with 2 cone shaped washers, that will center the part on the threaded rod. What are the diameters of the lights you are polishing?

 

[Data]

It is a good idea to spin the parts but spin them very slowly. See this video. That part was either titanium or SS 304.

I recommend you use your electric drill idea. Run the drill very slowly like in the video. Then use your Foredom at full speed (15-20K RPM) with a felt wheel and polish compound.

Because you are hand holding the Foredom buffer and the part is spinning slowly it will not matter that the part is not perfectly centered on the drill shaft. It will ride the part just fine.

Cheers
Dave

 

[donn_]

1/2" and up, Will. I spent an hour on McMaster-Carr looking for solutions, and I may have found one. They carry expanding rubber sanding sleeve drums (ala Dremel and Foredom) on 1/4" shafts. I ordered an assortment, from 1/2" to 2" diameter.

Cool video, Data. Where do I get the robot? I'll give that a try as well, but the way I'm doing this is by spinning the part at a moderate speed, maybe 1000 revs, and holding a strip of micro-sandpaper against it, lubed with WD-40. I use this procedure for larger smooth sections. For smaller stuff, I use 3M radial bristle wheels on the Foredom, and I also use rouged cotton twine on the spinning part (for grooves).

 

[Data]

Sounds like you have it handled, looking forward to the pictures !

 

[will]

Those expanding drums should work out fine...

 

[scott.cr]

Here's another take on expanding drums: Expanding mandrels at Enco! (Link HERE.)

 

[donn_]

While waiting for the expanding drums to be delivered, I came up with another idea, which will work for some parts.

This is a C-series Surefire tail cap, gutless, with a 1/4" machine screw bolted on. The 1/4" threads fit nicely in the Foredom 44T handpiece:

and I can screw any part with a C tail into the cap.

From there, I can add other parts, using the C-tail part as a mount. Here's an Aleph 3 head I'm working on:

The expanding drums are awkward to mount parts on, but once mounted and aligned correctly, they spin the part smoothly. This is an Aleph 1 head on a 3/4" drum: