Reducing the speed of a 200w orbital sander

Discussion in 'General Electronics Chat' started by SAEngraver, Aug 8, 2015.

  1. SAEngraver

    Thread Starter New Member

    Aug 8, 2015
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    Hello everyone,
    I am not an electrical guy at all, however I am looking to solve a scenario which I am sure to one of you will be basic. I look forward to a reply in laymens terms please.
    I make concrete castings from moulds. I use a simple orbital sander to vbrate the mould to get a nice smooth casting. The vibration at full tilt is somewhat too vigorous - can I slow this down with a gadget like they us in lights? A simple dimmer switch?
    Thank you
    Hans
     
  2. PeterCoxSmith

    Member

    Feb 23, 2015
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    cmartinez likes this.
  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    It would be much easier to use a variable speed drill with some type of unbalanced "bit" that would cause it to vibrate.
     
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  4. SAEngraver

    Thread Starter New Member

    Aug 8, 2015
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    Thank you for the information.
    unfortunately in SA we are sort of excluded from ebay as the postage costs of sending would be prohibitive.
     
  5. SAEngraver

    Thread Starter New Member

    Aug 8, 2015
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    excellent idea thank you - seems the easier way.
     
  6. Metalfan1185

    Active Member

    Sep 12, 2008
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    I use a Variac to control power tools on the lower current spectrum (like drills and dremel tools). Mine is limited to 10A but im sure larger ones are available. A Variac is essentially a variable transformer. 120VAC goes in, 0-140ish VAC comes out.

    Im thinking if the device is 200W @ 120VAC then it cant be more than a couple amps.
     
  7. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    I would try the light dimmer. It's only $5, and it's pretty much what is in a variable speed drill anyway. Start at full speed. If all seems ok, back it down to about 75%, let it run a bit, and assuming the motor slows down, see if either the dimmer or the motor are oveheating. The dimmer should be warm to the touch, but not burning hot.

    ak
     
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  8. SAEngraver

    Thread Starter New Member

    Aug 8, 2015
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    thank yo
    u, that's what I was hpopeing for - We run 220V in RSA. At an electrical wholesaler I found a plug socket with a "Dimmer" knob - going to get it and see if it will work.
    Regards
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    As long as the motor has brushes, you can take the edge off the power by putting a diode in series with its supply.

    Use a 1N5408 for 230VAC, or at least a 1N5404 for 120VAC.

    Wire it in the mains side of any filter components to give the diode some chance against back emf and arcing at the brushes.
     
  10. SAEngraver

    Thread Starter New Member

    Aug 8, 2015
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    Thank you for the interest
     
  11. Reloadron

    Active Member

    Jan 15, 2015
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    I would try as AnalogKid suggested in post #7. We used a similar vibration method for settling wet epoxy and the vibrator was driven by a simple SCR Light Dimmer control rated for 1,000 watts. Worked just fine. Depends on your motor but worth a shot.

    Ron
     
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