OK so I've been using the bead roller and it works much better with the reinforcement and motor drive. But I started this whole thing trying to get a foot pedal control, and I'm not quitting until I have that.
With Gordon's help we determined that my pot is a 100k ohm model, not 50k like the sewing machine pedals. With no good way to know for sure what the commercially available cheap pedals were, I decided to make one. My first idea was to get a little gear and rack from McMaster Carr and rig that to turn my existing pot, relocated into a foot pedal housing of my own design.
But Gordon pointed out that 100k slide pots are easy to get, so I bought one of those thinking the housing and linkage would be easier.
It came the other day.
Tested good:
I drew a + on the zero side ("this end down") and rooted about for a little metal box to put it in that will work with the EMPI gas pedal I bought for the Spyder and then didn't use.
Scrap bucket yielded treasure, as always.
Slotted it with the grinder.
Folded a little piece of .050 aluminum over the plastic slider to make it more rugged.
Snipped another piece into the rough shape of a c-shaped pushrod.
And that's all for now. I need to make a solid mount inside the box for the pot. There are little threaded screw holes in each end but I've no idea what screws fit it (tried eyeglass screws; too small). I'll probably use epoxy and some plastic bits to make a surround for it and snap it in place.
Ridiculous all around, I know.