soft bumpers for Oneway Mini-Jumbo Jaws

[Dr_dewey]

on a 10" swing lathe the mini-jumbo jaws will hit the ways when partially extended with the rubber bumpers in the outer ring position. see bumper.jpeg

took a 2" square piece of UHMW plastic which was 1.5" thick and resawed it in half and then cut the two surfaces into 4 equal squares to make 8 blanks. Then drill and counter-sink a hole in the middle of each to accept a M6 by 25 oneway screw.

Attach these to the mini-jumbo jaws and turn them to almost flush on the outside and trim them round on the inside. see UHMW bumper jpeg. I did this step with positioned on the outside thread positions. You could move them closer to the middle to reduce open air, but then you would have to carefully re-position them for alignment. I should mention that the outside edge does not have much room and you can touch the edge of the bolt heads with your tool! done that been there. i found i could ride the bevel on the aluminum plate to get in close to the bottom of the inside for a clean grip. You can put a small dove tail on the inside if needed.


then i was able to mount my ring with enough clearance to turn the bottom of the ring smooth.

 

[Jeff Jilg]

Thanks for posting that tip DrDewey, nicely done. I like the illustrative pictures and the general concept of making long extensions to hold the edges of a piece.

If you guys keep talking about UHMW, I'm going to get more curious and will have to get some to try out for myself. It looks like a nice material to work with.