Chuck stopper for Sherline Rotary Table

[j ferguson]

I found out the old fashioned way that if you want to chuck something up on the rotary table, you'd better prevent the chuck from turning.

Joe Martin was right, because the spindle turns the same direction as the chuck unwinds, it would be good to jam the chuck so it cannot turn. Using a tommy bar for this looked good and this is what I'm going to make.
I'm a little surprised that Sherline hasn't gotten around to making something like this available, but alas.....

Drawing was done in OnShape, but the bracket itself will be done in Creo from which I will generate the G-Code for my 2000.

 

[j ferguson]

Well I made it. 6061-T6 although maybe steel would have been better. My theory it that this will stop the chuck from rotating when bolted to a rotary table and if it needs to be stronger than it is, maybe I should be doing whatever some other way.

The idea is that the tommy-bar is prevented from moving counter-clockwise by the post on the "chuck-stopper"
The chuck-stopper is bolted to the rotary table using Sherline's little T-nuts, then moved so that the post is pressing against the tommy-bar then secured to the rotary table be tightening the cap-screws.

I still need to counter-bore the post so the top will be flush with the face of the chuck giving me the clearance to cut up to the face of the chuck if I ever need to.

If anyone is interested, I can email a drawing and the g-code for the bracket which will run on a Sherline CNC 2000 using LinuxCNC.

 

[j ferguson]

Here's the drawing