Mini Maestro 12 for controlling a BLDC motor with an ESC

I’ve bought the Polulu Mini Maestro 12, with the goal to drive a Brushless DC motor (from an old Hard Disk Drive). I’ve bought an ESC for this as well: Modelcraft Hurricane Heli SP-20 BEC.
I’m using an old computer Power Supply Unit for power, and on the motor I’ve added fly-back diodes to protect the ESC when the motor is braking.
I’ve wired it up as follows:

I’m encountering some problems with getting the motor to spin.
Assigning the maestro output as a ‘servo’ I get jibberish movement in both directions, and ultimately with a lot of fiddling with the target bar in the Maestro Control center I can get the motor to spin but very slowly…
Assigning the maestro output as an ‘out’ and PWM, nothing happens.

I’m not sure whether I’ve missed some special setting or something, when using the Maestro to control an ESC.
As well I’m a novice regarding electronics so I’m already out of idea’s what the cause may be…

I hope to receive some tips here so I can get the motor to spin at its full capacity: 10k rpm :wink:.

Kind regards


I suspect that those diodes and motor ground connection are completely inappropriate for use with that speed control. I don’t know if that motor can work with that speed controller, so you should focus on that. You should quickly confirm that you can get your system working with the typical brushless motor that speed controller is made for (they have three wires coming out of them and you can get them quite cheaply), and then you can try substituting your hard drive motor.


Hello Jonathan

Thank you for your reply.

Indeed you are probably on the right track, I saw a Youtube video of the combination ESC - BLDC HDD motor and that person left the 4th wire (common wire) of the BLDC open.
I will look into it.

Also, I’ve updated the picture above since I realised I drew two of the diodes the wrong way :slight_smile:.