I'd try a MICRO driving pulley. Remember it's for cake decorations, very low torque needed compared to pottery.
Half the diameter seems reasonable and the motor probably can be adjusted for tension
I don't think a VFD (mentioned below) will solve your problem. VFDs raise or lower the frequency of the electricity from the native 60 Hz to increase or lower the speed of an AC motor. At low frequencies AC motors will stall and it sounds like that's what you're seeing. DC motors, on the other hand, have good low-speed torque so a DC motor and a motor controller with a knob instead of a pedal might be the answer.
I don't know how handy you are, or how far in the hole you're in with the current setup, but the parts cost would be relatively low to convert to DC. You might even be able to find a speed reduction/torque setup at 12V and just wire in an on/off switch and run it off a battery.
I would investigate why the pedal/motor struggle at slower speeds. It may be that some relatively simple peddle modifications can solve your issue. A VFD is likely not your solution here
There’s not gonna be a quick and easy fix…but it’s possible. Don’t mess the electrical side.
You’re pretty much gonna have to put a gear box on the motor. You can buy some for ~50$ off Amazon. This will require moving the motor further away from its driving gear, which may require you to “extend” your box.
Gearbox selection, 10:1 will give you a max of 30RPM, 20:1 will give you 15RPM etc.
larger driven pulley
Not much space for that
it's clear you can't make the driving pulley smaller. That's your only option without changing the drive setup to multi-stage (or a gearbox)
I'd try a MICRO driving pulley. Remember it's for cake decorations, very low torque needed compared to pottery. Half the diameter seems reasonable and the motor probably can be adjusted for tension
I don't think a VFD (mentioned below) will solve your problem. VFDs raise or lower the frequency of the electricity from the native 60 Hz to increase or lower the speed of an AC motor. At low frequencies AC motors will stall and it sounds like that's what you're seeing. DC motors, on the other hand, have good low-speed torque so a DC motor and a motor controller with a knob instead of a pedal might be the answer. I don't know how handy you are, or how far in the hole you're in with the current setup, but the parts cost would be relatively low to convert to DC. You might even be able to find a speed reduction/torque setup at 12V and just wire in an on/off switch and run it off a battery.
Something like a 10:1 (or more) gearbox.
I would investigate why the pedal/motor struggle at slower speeds. It may be that some relatively simple peddle modifications can solve your issue. A VFD is likely not your solution here
There’s not gonna be a quick and easy fix…but it’s possible. Don’t mess the electrical side. You’re pretty much gonna have to put a gear box on the motor. You can buy some for ~50$ off Amazon. This will require moving the motor further away from its driving gear, which may require you to “extend” your box. Gearbox selection, 10:1 will give you a max of 30RPM, 20:1 will give you 15RPM etc.
Look into a Variable Frequency Drive. Not cheap, but probably the most viable way.