Duplicator for wood & soft metal turning:
(click on the thumbnails for a larger image)

I was planning to make a chess set. The thought of turning all those pawns and keeping them "somewhat similar" in shape was a good motivation to think about a duplicator accessory for the the lathe. I had seen some duplicators for larger lathes which gave me a good idea of how to approach it. I wanted something simple and sturdy which would not interfere with the normal operation of the lathe and could be driven by profile templates made from thin acrylic sheet.The idea is to mount a tool post on holder which is free floating on the bed. A stylus on top of this floating tool post holder tracks the template held in a rack mounted above the lathe. The first thought which crosses your mind with this arrangement is that the tool holder not being attached securely to the lathe will be unstable. In fact it is very stable. The forces working on the cutting tool while turning keep the holder solidly in contact with the bed surface.

These pictures show the basic set-up. The bed of the lathe itself is not wide enough to allow enough movement in and out so an extension has been added in front of it at the same height as the bed and running parallel to it. The cutting tool is a modified parting tool held in a slot on the holder which allows it to be adjusted forward and back. The stylus is a brass bar with a replaceable tip and can also be adjusted forward and back. The profile of the stylus tip and the tip of the cutting tool are identical.

 

 

This picture shows the bed extension and the front of the tool holder. There are two positions on the tool post for both the stylus and cutting tool. The top most position for each is for when with the lathe headstock and tailstock risers are being used. The bottom position is when the lathe is set-up with the risers. The risers give the lathe a greater swing over the bed for turning larger diameter pieces.

Here's a close up showing the relationship of the template and the work piece.

Here's the final result. Of course the knights are a little trickier.

 



Last changed February 16, 2004