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How do I determine the power of my motor?

  1. Jan 30, 2012 #1
    http://pokit.org/get/698d568001a73aa07d3a98d9ad7672c6.jpg [Broken]

    This has been take out of old printer. I also found a stepping motor.

    I want to use this for my heli project.


    They suggested brushless modification of motor from CDrom. I am holding that for last reserve.

    How do I know what are the parameters of this motor? What power it needs etc.
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Jan 30, 2012 #2
    http://www.mabuchi-motor.co.jp/cgi-bin/catalog/e_catalog.cgi?CAT_ID=rs_385sh [Broken]

    always google the part number and you may get lucky :wink:
    Last edited by a moderator: May 5, 2017
  4. Jan 30, 2012 #3
    I did google it. I didn't get lucky :/

    Thank you.
  5. Jan 30, 2012 #4
    weird, I enter "RS-385SH" and I get lots of hits
  6. Jan 30, 2012 #5
    Then miss typed something :D Thank you. Now I have to figure out physics or RC chopper.But I think this motor will do.
  7. Jan 30, 2012 #6
    Ahhh yes. Now I see in history. I typed R8 instead of RS :D
  8. Jan 30, 2012 #7
  9. Jan 30, 2012 #8
  10. Jan 30, 2012 #9
    No no I meant the motor I have, to modify to have at least 29,000. its max is 10,000.
  11. Jan 30, 2012 #10
    You probably wouldn't want to try, and I'm not sure what the equations for it are but you'd want a larger back-EMF on the coils since your RPM is directly proportional to that parameter.

    You're probably better off finding a simple and cheap gear ratio assuming your motor can supply more torque than your max you will need. You will get higher RPM, but less torque if you step up the revolutions with a gear.
  12. Jan 30, 2012 #11
    Gears. Of course. Forgive my troubled mind, college has taken away my creativity :(
  13. Jan 30, 2012 #12

    jim hardy

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    i'd think fewer turns of larger wire would give more speed

    back EMF = K * flux * rpm

    and field flux is set by permanent magnet .
    so with fewer turns the rotor will have to turn faster.
    In other words, K includes number of turns.
    Current will be higher so put in biggest wire you can fit.
    but centrifugal force is square of speed - brace them in well.
  14. Jan 30, 2012 #13
    Hopefully that's a possible option, but remember to check if it will give you the required torque at those higher RPMs.
  15. Jan 30, 2012 #14
    It probably will. I find this motor to be very robust. Little math will probably confirm that.
  16. Jan 30, 2012 #15
    I will probably go with gears, since motor is well tucked in, with no screws or anything.
  17. Jan 31, 2012 #16

    jim hardy

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    gears sure sounds easier.
    just a thought -
    check junkshops for battery operated small vacuum cleaners, little dustbusters and the like.
    They have a very powerful high speed motor inside.
    Frequently they are discarded when batteries give out.
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