Potters wheel

  1. RHS Member

    Messages:
    11
    Location:
    Aberdeen
    Hi all,

    I'm looking for some advice before I start my next project, my wife has requested that I make her a potters wheel. My current thinking is to design it around a car wheel hub bearing assembly, with a belt drive to a motor of some sort. I'm reasonably happy with the mechanical side of things, but am not sure what sort of motor to use or how best to control it. Her research suggestst that a 1HP motor is what she's after.

    Any advice would be gratefully received, particularly around what sort of motor/controller I should go with.

    EDIT: variable speed control is required apparently

    Cheers,
    Robbie
     
  2. pedrobedro

    pedrobedro Man at Matalan

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    Industrial sewing machine with pedal speed control might be enough depending how much weight she is slapping on the turntable.
     
  3. There used to be many variations on drives for potters wheels but since the availability of cheap Variable Frequency Drives the easiest way is a 3 phase motor and a VFD with a speed control pot in a foot pedal.
     
  4. julianthegypsy Member

    Messages:
    2,574
    rugby UK
    I doubt it would need a horspower, bearing in mind that many potters still use a treadle. I think the wheel should be heavy though, to give it momentum, so when you start pushing into the clay it doesn't just stop.
     
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  5. brokenbiker

    brokenbiker Member

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    from my limited knowledge of pottery wheels, they are the same as flywheels, small input starts them turning slowly and builds up speed, then the motor merely assists the wheel, and a bicycle wheel type brake is there to stop it gently. Or at least thats how the one we had in school worked
     
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  6. Maker

    Maker King in the North

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    Yeah, that sounds about right, it's all about momentum - make the table/surface from the thickest steel you can to give it more mass.
    I don't know how fast they should spin but I would guess between 60 to 200 rpm. Using a 2 pole motor most inverters will turn it at anywhere between 280 to 4000ish rpm so you could do with a 20 to 1 reduction belt.
    If you make the table 400mm dia you could put a 20mm pulley on the motor and have a belt running against the outside of the table and the motor pulley and then make up a foot pedal to control the inverter. You could probably get away with using a tiny motor like 1/4 hp because your getting the equivalent torque as a 5 hp 2 pole motor (but 20 times slower) but you may need to throw the wheel by hand to start it.
     
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  7. MattF

    MattF Forum Supporter

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    A gearbox reduction motor coupled with a variable speed pulley might be the best way to go with that, if you're wanting electric. It'd be easy enough to have a foot plate vary the position of the motor slightly. I'd be tempted to go with treadle power though.
     
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  8. Maker

    Maker King in the North

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    Or what about pedal power?:D
     
  9. brokenbiker

    brokenbiker Member

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    speak to colin furze, he can probably knock you up a jet powered job
     
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  10. Maker

    Maker King in the North

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    ...or a 600cc one.:laughing: Give him a week and he'll put guns on it:laughing:.
     
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  11. Brad93

    Brad93 M J B Engineering

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    1 hp will be well over the top almost dangerous!
     
  12. mr migwire

    mr migwire It's more fun with metal.

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    get an old sewing machine and strip the motor out, use it along with the control pedal, theres hardly any loading on the wheel so a simple belt drive should suffice.
     
  13. Depends on the size of the pot you are throwing, I used to throw a few pots when the kids were small (MIL would babysit while me and the missus went to evening classes) and a sewing machine motor would definitely not have coped with what I was throwing!
    We have a well known potter near by and their wheels run 8 hrs a day 6 days a week and certainly have alot of grunt as they can start with a couple of Kg of clay on the platen.
     
  14. MattF

    MattF Forum Supporter

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    Problem with the sewing machine motors is that they're quite fast too, as I recall? Seem to remember them being around the 3000RPM or so range.
     
  15. Maker

    Maker King in the North

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    But gear it down and it might be quite suitable.
     
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  16. mr migwire

    mr migwire It's more fun with metal.

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    gear them down with a belt and pully assembly and limit the travel on the foot switch...
     
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  17. MattF

    MattF Forum Supporter

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    Aye, it would obviously work with slowing it down with gearing or pulley ratios. Just seems that it would be better to start with something a bit slower and save that extra step being needed.
     
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  18. mr migwire

    mr migwire It's more fun with metal.

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    a direct drive from a small motor would probably work if you use one of the afore mentioned VFD. which as matt says would remove the exra steps required...
     
  19. Maker

    Maker King in the North

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    AFAIK, the only motors slow enough to be used for a direct drive potters wheel's would be either stepper/servo motors which are expensive powerful ones and need expensive drive circuity or hydraulic motors which are also expensive and need expensive pumps and motors. It's cheaper and easier to simply use a belt and pulleys or a gearbox. Also, a motor may not like having the heavy table mounted directly to it with clay being thrown at a, i.e. they don't have thrust bearings to take very much axial load.
     
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