The cable winding pulley was the most complicated part of the machine due to it’s multiple set screws, flat surfaces, precise bore, and threading. One set screw holds the pulley on the shaft. The other set screw holds the cable firmly attached to the pulley.
Here is a picture of the pulley mounted to the DMM Tech Servo Motor. In the background you can see the cable go up through the top of the machine, over the free pulley, and back down to hold the main slider mechanism.
A friend of mine needed a bushing assembly for his street bike to be reduced in width by about 0.230″. Having a 1930’s South Bend Lathe in my shop, I naturally said “come on over”.
My respect for machinists just went up a few notches (it was already high). I’m also glad I got a 4 jaw chuck for the lathe instead of a 3 jaw.
4-jaw chucks allow you to hold irregular work and precisely center it. The process for doing so can be tedious, but it’s a good feeling when your indicator reads in at less than 0.001″ variance from side to side.
This little project was fun for a few reasons. The assembly comes apart into several pieces. The little ring has multiple inner diameters used for different things, so it needed to be machined carefully on both sides. Holding small and irregular parts is a challenge. But seeing it all come together was great.