Pot Chucks for 5C Collet Systems

2 months by cncdivi

The Hardinge 5C collet system is an intriguing lathe workholding set-up. I obtained a brochure from Hardinge which explicates the entire system and advises on how to maximize its effectiveness. The system was thoroughly thought of a long while back and I surmise that the significant success of Hardinge during that era was largely due to the adaptability and efficiency of the 5C system. One of the serviceable characteristics of the 5C system is the “Post Chuck”. Comparable to a milling machine’s soft jaws, pot chucks play a similar role in this lathe system.

Here is a nifty picture showing the many uses of a “Pot Chuck” for offset work:

No idea what those parts are, but they are sure cool, eh? Someone suggested in an email to me that they are fine adjustments for a Norris-style wood plane…

A pot chuck is a 5C collet that can be modified to make a custom collet for your work. This fellow has made one that takes the little offset slugs to machine the brass. You can see he has quite a little variety for whatever it is he is producing on his mini production line. Note that each little slug lines up a different portion on the center line for easy access in the lathe. From left to right there is the little nib that sticks out, then the little set screw that clamps the thing to the thread (a backlash adjustment, perhaps?). Moving along we see three collet systems, one to machine the threaded portion, one to turn the ball, and the last one to allow the ball to be bored.