I have always had clutch motors on my sewing machines and currently have one driving my walking foot machine. It serves me well, but is hard to control at very slow speeds. It wants to either stop or run, when I want it to tick-tock around curves and strap tips. I am considering buying a servo motor to replace it, but am curious about how they are controlled. I want one that will go from about 1 stitch per second, with the floor pedal backed nearly off, smoothly up to full speed (as per my pulley ratio) with the pedal fully down.
It seems that every servo motor I read about is controlled by a pot on the back of the motor, with no mention of the foot pedal having any control over speed (or am I mistaken?). Are there any brands of 1/2 HP servo motors that are speed controlled by the foot pedal, rather than just by a knob on the back of the motor? In other words, behave the same as a clutch motor; from a dead stop at heel down, through variable very slow through medium speeds as you toe down, up to the motor's full speed at full toe down. If so, what are those brands or models and who has the best prices for them?
If there aren't any such animals, are the pot controlled motors just switched to full on when you press down of the floor pedal, with the pot determining the one speed at which they run? Do they come to a dead stop when you heel down, like a clutch motor?