Vfd won’t work on a single phase motor. You’d need to replace it with 3 phase, or find a 6 pole single phase, which would run at 2/3 speed, but as rare as rocking horse droppings. You mug t be able to fit a DC motor

First post on this electronics forum says: “The motor is an AEI BK-2410-C B56, it’s 4 pole 3 phase 415/230V 1hp / 0.75kW“.   If true, then a VFD is the answer, but it begs the question of how the wheel is powered at the moment?   Most of us don’t have a 3-phase supply.

We need to correctly identify the motor and how it is controlled.   Most helpful for MrCharly to provide photographs of the motor, the wiring inside the motor’s terminal box, the control switches, and anything inside or outside the cabinet the cabling connects to up to and including the mains plug.

Dave

I have only delved into the internals of a potter’s wheel on one occasion, and that certainly used a VFD and 3-phase motor. Also had a strange mechanical linkage allowing a foot pedal to operate a pot for speed control, although it seemed to work OK. Well, until the VFD gave up the ghost, which is where I came in. That wheel belonged to a professional potter.

While my preference would be for the VFD/3-phase solution, I wonder if this might also be an application for the DC sewing machine motors that often get mentioned in this forum, available at relatively low price complete with speed controller. Don’t have a source for them, but my guess is that they would meet the speed control and power requirements.

A sewing machine brushless DC motor responds very quickly to speed changes including rapid deceleration with dynamic braking. Good for sewing machines but possibly not so good for potters wheel. Wheel may stop but not the pot. There may be a parameter in the BLDC controller that sets braking performance but it will depend on controller make.

VFD’s can be set for dynamic braking or coasting to stop.

CS

Thanks, Charly

On that evidence, the first two responses are appropriate

… but pictures would be most welcome and reassuring.

MichaelG.

Potters wheels are not something I knew (know) much about until recently when I was asked if I could repair one that had stopped working.

The machine sound similar to the OP’s in that the speed control was purely mechanical inasmuch as it had a variable ratio transmission. Rather than the leather wheel on a platen it had a conical ‘pulley’ on a motor shaft that engaged with rubber tyre on the edge of a large disk below the table. The motor was movable by a foot pedal to steplessly change the contact position between the tyre and the cone diameter.

I do not know how the latest or modern potters wheels are driven but I suspect if electronics are involved it will be tailored to suit this specific application. I think the pure mechanical drive has characteristics and a feel that a potter gets accustomed to so a VFD with a pot might not cut the mustard.

I think the OP only really has two options, one being to re-engineer the leather wheel so it is smaller diameter, the second being some sort of motor swap, say to a two speed induction motor or a VFD and three phase motor.

Ian P

Edit, JD2 beat me to it

The motor has a capacitor? If yes then I think there can be two cases. First, if it is a permanent split capacitor motor it should work with a VFD. Especially if you don’t want to adjust the speed over a wide range. But if it is a capacitor start type then it will not work.

If the motor is a simgle phase, I would expect it to be fixed single speed (1470  – 4 pole 2940 2 pole)

To slow the wheel will entail either changing the motor, (to 4 if a 2 pole, or to  3 phase and VFD), or mechanical methods, such as smaller driving wheel or larger driven wheel.  Would be much easier if were belt driven.

Can you make up and fit a smaller driving wheel, and / or arrange the driver to contact the driven wheel closer to the centre?

To complicate matters, if space close to the driven wheel is too small, make up and fit a smaller driver, onto an idler, and change the start windings over, to reverse the motor direction of rotation.

Howard

Excellent, thanks

… I am quite sure that a simple motor swap [to 3-phase with VFD] will work wonders.

MichaelG.

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Edit: __ some useful drawings of modern frame-sizes here:

https://www.electric-motors.online/products/motors/b56-motors/

Funny,that Ian … I was seeing a nice new ‘Drip Proof’ 3-phase motor as a major improvement in safety.

MichaelG.

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P.S. __ if Charly does elect to make the simple pulley change, a Poly-V pulley should obviate the stated problem with ‘wrap’

Regulations are not what they were, or more accurately they are more stringent than when his wheel was manufactured. Safety could be ensured by the electrics (and the finger trapping belts!) being in a secure cabinet so what is inside becomes less relevant.

Another vote for PolyVee. It would however mean two new pulleys and belt, whereas keeping the existing large pulley just fitting a new smaller motor pulley and moving the motor in its slots would be a simple cost effective answer. Pulley might have to be made as its unlikely to be stock item.

Ian P