Development of best servo motor for leather sewing machine

[GerryR]

In the system I have (AC-VFD), the motor is spec'd at 35-459 RPM, 10-90 Hz.  That is the output from the 5:1 reducer (gearmotor).  I have a 1-1/2" motor pulley going to a 7" drive pulley for another 4.67 reduction giving 7.5 RPM at the machine at 10 Hz (minimun specified operating frequency for the motor), which amounts to 0.125 revs.per second or 1 revolution every 8 seconds.  But that is not the point.  The point is that when I hit the pedal, and the motor starts to move, I am easily in the safe operating zone of the motor, 10 Hz minimum.  It would be absurd to run the machine at 1 stitch every 8 seconds for any length of time.  The idea is to keep the motor happy and stll be able to do some controlled slow stitching.  Just my $.02

[StitchDoc]

On 7/16/2025 at 7:05 PM, Wizcrafts said:

Despite all of the improvements made in electronic motors over the last almost 20 years, I can still feather a clutch motor so it barely turns over the machine, and hold it at a slow and steady speed. Yes, they are noisy and generate a bit of heat. But, they are like the Ever Ready Bunny: they just keep on going!

If anybody reads this and is having trouble controlling a clutch motor, try backing off the big screw on the clutch housing. This adds a certain amount of slack movement before the disks engage. You can also tighten the coil spring that holds back the clutch lever. That keeps the lever up and away from engaging accidentally. Finally, you can smear a little grease on the internal cork disk that mashes into the main disks. The final adjustment is to replace a large motor pulley with a 2 inch pulley, or to add a 2:1 speed reducer.

Wizcrafts, would you be able to show me on the attached photos where the big screw on the clutch housing is as well as the coil spring that holds back the clutch lever? I'm not sure where they are.

Thank you,

Phil

[AlZilla]

9 hours ago, StitchDoc said:

Wizcrafts, would you be able to show me on the attached photos where the big screw on the clutch housing is as well as the coil spring that holds back the clutch lever? I'm not sure where they are.

Thank you,

Phil

I don't know what that's called exactly but it's not what people mean when they say "Clutch Motor". It accomplishes something similar  I've got a couple of those and some clutch motors. A clutch motor has something akin to an automobile clutch built right into the end of the unit.

Here's Alexander Dyer talking about clutch motors: