Pot chuck

[mklotz]

Machining the face of a thin disk can be a trial. Superglue or jeweler pitch chucks are fine for one-offs but for multiples a pot chuck can be an asset. Commercial 5C pot chucks are available but a hobbyist may not want to buy something he will only use very occasionally. It's a straightforward task to make your own as this example shows...

This one is made to be mounted in a 3jaw, 4jaw or collet chuck. The body is machined to shape with a 1/4" through hole. Three slits made with a slitting saw allow the hose clamp to tighten the three jaws down.

To use it you insert a 1/4" pin in the hole and clamp it using the hose clamp. The front of the chuck is then trepanned to the diameter of the workpiece and a depth sufficient to get a grip on it. Loosen the clamp, remove the pin, insert the workpiece and tighten the clamp to grip the workpiece. The whole assembly is then mounted in the chosen chuck on the lathe and the workpiece is machined.