# Controlling a servocity planetary motor?

I know this might sound like a stupid question, but I actually need help with this. So, I'm looking at this motor: https://www.servocity.com/2737-rpm-premium-planetary-gear-motor.

I have a raspberry pi, and was wondering how exactly I was supposed to control this. I know that I need a motor controller to drive this thing at a reasonable speed, but I need someone to point me in the right direction as to what type of motor controller I need. Thanks!

• what does servocity have to say about it? Commented Feb 20, 2018 at 19:08
• @jsotola Nothing really. Just that it's a male spade connector or whatever. Commented Feb 20, 2018 at 19:29

This is just a standard brushed DC motor.

What you use to control it (how you control it) depends most on your application.

The Motor Specs are:

• Voltage = 3V-12V
• Speed = 2737 rpm (12V, No Load)
• Current = 0.18A (12V, No Load)
• Current = 4.9A (12V, Stall)
• Torque = 9.72 oz-in (12V, Stall)

Some things to consider from this:

• If you want to run at 2737 rpm, you better make sure you have a 12V supply and a driver than can drive 12V. If slower is fine, lower voltage would be OK, The rpm will scale pretty linearly with the voltage
• If you need to be able to support a stall condition, you should make sure the driver can support 5A (or at least as much as you supply can).
• Since this is a brushed DC motor, the speed is unregulated. The speed will result from a balance between input power (V X A) and output power (rpm X torque). You can add a separate control loop (like using an encoder) if you want to regulate speed. Some controllers support encoders.
• I assume you want to regulate the motor's power. If so, something has to do the PWM. This can be done by the Pi or a separate controller.

The one I'd suggest for your motors is the RoboClaw 2x7 Motor Controller.

This takes control signals from the Raspberry Pi and powers the motor from a separate battery. The board should be able to power your Raspberry PI because it has a 5v 3amp BEC (battery eliminator circuit). You would need a battery of no more than 12 volts to power the motors.