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Reducing motors RPM

Discussion in 'Electrics UK' started by gardeners26, 5 Feb 2006.

  1. gardeners26

    gardeners26

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    I have a small mains motor (the type used in a microwave) with a speed of 12rpm. This is slightly too fast for my robotics application-6 to 8 rpm would be better. How do I achieve this?
     
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  3. Adam_151

    Adam_151

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    with gears
     
  4. andy

    andy

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    gears. or you can change the power going into it, but this can be complicated
     
  5. breezer

    breezer

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    depends on type of motor, gears will work, but best get a motor for the job as it will be less haslsle all round :(
     
  6. kendor

    kendor

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    depends on how much the budget for the robotics allows but you can get your hand on some really cheap motor controllers/invertors that will control the motor speed with range full speed to stop.
    search for controllers to match your motor.
     
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  8. Jaymack

    Jaymack

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    Try a dimmer switch, wattage twice the rating of the motor.
     
  9. Big_Spark

    Big_Spark

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    For what you want why not simply a purchace a DC motor so you can control it via voltage?

    As has been suggested, gears are the best method in this situation, the only other way to slow the motor would be with an inverter which alters the frequency of the supply to the motor, as one of the main determining factors of AC motor revolutions is supply frequency.

    However this would prove an expensive route to go, buying a 1.5/1 gear ratio kit from maplins or a model shop would be by far the simplist if you insist on using this motor rather than sourcing one more appropriate to your task.
     
  10. gardeners26

    gardeners26

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    (slight correction to question. "I have" should read "I propose to have".)

    Thanks guys for all the advise. Seems I need to go back to the drawing board. so in more detail:
    I have a 12inch dia. turntable on which sits a load of 7Kg. It,s required to turn (and reverse) through 180 degrees i.e. half a revolution,in about 6 seconds i.e. 5 rpm. The present set up uses the turntables own 1.5v dc motor powered by an adaptor adjustable from 1.5 to 12v. ( and yes I know the motor would burn out if used for much longer than 6 seconds!) and is swithed via an electric window switch from a car. Set at 4.5v it works perfectly but for one problem.
    The motor rotates a cheap plastic cog which in turn drives the teeth on the inner rim of the turntable. The increased voltage increases the speed necessary due to the weight of the load. However the cogs always slip upon startup prior to engaging.
    So should I be looking for a direct drive (to the centre of the turntable) high torque,12v,5rpm motor-if so can you suggest a supplier or another means of powering the tuntable. Many thanks, Roy.
     
  11. big-all

    big-all

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    just an aside

    isnt there all sorts of safety issues and mechanical protection involved with mains current

    just a thought :D :D ;)
     
  12. DIYnot Local

    DIYnot Local

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