@DPittman - this problem too will be simple when solved.
Please keep sharing. Looks like a project that could buy me more points than I've lost in my whole married lifetime of 51 years. My bride is a seamstress and she is always yacking about the need for more speed...... control.
Mind you, convincing her to let me play with her machines because "I know what I'm doing honey" might be more difficult than executing the project itself!
Well I finally wrapped up my sewing machine project.
The sewing machine is a 1936 Singer that had a clutch drive mechanism that made the sewing machine extremely difficult to "drive". It was made for experienced factory workers with a need for speed. When I got the machine the drive was non functional and bastardized anyhow. I decided that a salvaged treadmill motor would be a good fix for the drive if I could figure out how to adapt it all.
The first thing I did was make a much larger driven pulley on the machine to slow things down and then I made a drive pulley for the treadmill motor. I had to make new mounting plate/brackets, motor cover and motor speed control board covers.
The original treadmill motor speed was controlled with a potentiometer and I wanted to adapt that to use with the original foot pedal. Mistake #1.
After many failed attempts of using salvaged drill gears or belt and pulley systems to change the linear motion of the foot pedal into a partial rotary motion to control the potentiometer, I finally got it working. As seen above, I ended up cutting my own gears to achieve the right ratio. Figuring out a crankshaft mechanism of the proper stroke was most challenging.
While the sewing machine looked horrible when I got it, the mechanics of it was surprisingly smooth and incredibly well built.
I cleaned and repainted but did not spend as much effort on repainting as I may should have. I didn't bother with new decals and such as this was never going to be a show machine. I restored it to hopefully sew the odd animal harness, tractor seat cover, tool pouch etc. I won't be the operator of it but will give it to my more capable brother for that stuff.
The original hardwood table was also in very rough cosmetic shape so that just got fixed and repainted.
The sewing machine is now quite easy to operate and has great power but the soft stop and start of the treadmill motor control board takes a bit of planning and getting use to.
The sewing machine is extremely smooth running and considering it is 87 years old, it is very impressive how well made they were.