Rim Sanding Jig

[Tj Turner]

Evening all...

I thought I'd share the new jig I finally got around to finishing. I've been tired of my old sanding jig being a little too flimsy, so I tried to make something sturdier. I still need to drill the holes that will bolt down the mold, and I think I have a unique solution for leveling up the sides (which I'll post as soon as I get my next rim built up).

But for now...here's the jig. I use a sine-table like device with a precision ground 1.5" shaft in the center. The shaft is held in place by brass bushings, and then a collar holds the shaft in place at the bottom of the central structure. I did that because eI used to have issues with my old jig, where the shaft would pull out when I tried to dismount the radius disks. I also didn't like my old way of setting the angle, so instead I made a sliding fixture with a 1" round dowel (I may replace this with a 1" precision ground shaft, but there is probably little advantage). I have a Matlab script running that tells me acutely what angle I need to be in order to square up either my back or top rims, and therefore the setback for the dowel along the jig.

I think this will be a much better more secure method to sand my rims...

[Tj Turner]

A few more shots...