What kind of control is this

[Mifa2024]

I have an old mixer/food processor, from the late fifties or early sixties. It uses a universal motor, but I have never seen the kind of mechanical speed control that is used. Can anyone identify this type of mechanical control, and how to adjust it?
Thanks for your help.

View attachment IMG_1487.mov

 

[waross]

We need some more pictures. What actuates the control arm?
Centrifugal? Some other method?
It is a mechanical chopper circuit and the farther the control is turned, the greater the speed needed to interrupt or "chop" the feed to the motor.
It may be well to replace the capacitor before proceeding further.
That may be all that is needed.