Help selecting a motor


I was wondering if anyone could suggest a motor that is (1/3)HP and operates at 500 rpm that can be easily interfaced with arduino? I have the arduino controlling a relay (sainsmart relay: SainSmart 4-Channel 5V Relay Module for Arduino Raspberry Pi – . I would prefer if the motor is DC and as low voltage as possible.

Also, any suggestions for DC power supply ? A battery may not work since the current drawn will be quite large.

1/3 HP is roughly 250 Watts. I doubt you are going to find any at any low voltage since even at 10 Volts it would be drawing 25 Amps! I would not go lower than 12V and would go as high as you can manage. At 24V you are controlling more than 10A.

If you want to draw 250 Watts from batteries I would look into using 12V lead-acid batteries. That would give you a current of about 20.8A. Divide the battery Amp Hour rating by 20.8 to get a rough idea of how many hours you can run at full load.

The raw motor wil probably turn at 1750 to 3000 RPM so you will need a reduction gearbox to get your 500 RPM.

Here are some example motors from
OMPMDC13-18-12V-56C $261.00 12 volts, 1/3 HP, TENV enclosure
OMPMDC13-18-24V-56C $259.00 24 volts, 1/3 HP, TENV enclosure
OMPMDC13-18-90V-56C $219.00 90 volts, 1/3 HP, TENV enclosure
OMPMDC13-18-180V-56C $217.00 180 volts, 1/3 HP, TENV enclosure

Note how the price goes up as the voltage goes down. Probably because of the heavier copper wire needed to carry the current needed at lower voltages.

Hello John,

That was indeed very helpful, thanks a lot.. :slight_smile: