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Need Help Selecting a Motor

  1. Nov 28, 2015 #1
    Hello, I am working on a design, and I am having trouble selecting a motor. I will be able to supply 1.2 A and 12VDC, and I need the motor to be able to move a load of 0.5 lbs at 500 rpm. So far, I tried calculating torque (based on F=ma and T=Fr, r=1.06 in in this case). Then I used HP= (T*omega)/5252 to get a required Horsepower of 0.5. But I feel like this is wrong. Any advice would be greatly appreciated!
  2. jcsd
  3. Nov 28, 2015 #2


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    Move a load of 0.5 lbs at what speed, or should that be a load torque of 0.5 ft lbs at 500 rpm == 0.047601 horsepower ~= 35.5 watts. Input power is 1.2A x 12 V = 14.4 watts, so you'll need a bigger power supply.
  4. Nov 29, 2015 #3


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    As rcgldr said.. There is an issue with your units.

    It takes power to accelerate a flywheel but the only power required to spin a 0.5lbs flywheel at a constant 500rpm is the power required to overcome losses (such as friction and/or air resistance).
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