How to control a micro gearmotor 998 with an RC receiver

Hello all,
I have some knowledge in electronic, but I’m really a newbie in “robotics” :slight_smile:
I’m looking to replace the air thrustors of an RC plane retractable landing gear by a micro gearmotor/controller.
This video will help you in understanding what i’m trying to do :slight_smile:

The purpose of my modification is to connect a threaded rod to the 50:1 micro gearmotor, which will actuate the gear.

Also, i really don’t know which driver i need to buy to :

  • drive the motor gear on the both ways (extend and retract)
  • control the driver via my rc reveiver
  • get “endstop” with no endstop switch. maybe the gearmotor current is the way to go to get a really easy system?

As for the video it seems the way to go is with a Dual MC33887 Motor Driver Carrier #712 but it is no longer available… Then please help me :slight_smile:

It’s not a problem for me if there is something to program or adjust :slight_smile:
Thanks a lot for your advises

I forgot to mention,

My RC reveiver is powered with 6volts receiver battery, but i would like to have a dedicate battery for the gearmotors power, like a 2s Lifepo4 (6.6v) or 2s Lipo (7.4v) battery

So my question is : is it possible to have the “control” part powered by the receiver, and the power of the gearmotors connected on a different battery ?

Thanks again


Maybe this video can help as well :

Thanks again


The replacement for the dual MC33887 motor driver (#712) is the dual MC33926 motor driver.

However, if you want something you can control with an RC receiver, I suggest you consider our Simple Motor Controller 18v7. The user’s guide is available from the product page resources tab, and I think it will answer your questions. If not, please ask.

- Ben

Hello Ben
Thanks a lot for your answer :slight_smile:
Tell me if i’m wrong, the dual MC33926 motor driver has a built in current feedback circuit for each motor, which needs another circuit to be usable (if yes which one?), but no possibility to control it via my rc receiver (rc signal)

And it is the opposite for the Simple Motor Controller 18v7, rc signal ok but no built in current endstop possibilities…

Arf, i was wondering to find a tiny system able to do those functions :frowning: so sad.

Let me know
Thanks, Manu

Yes, the MC33926 provides feedback about the motor current in the form of an analog voltage that is proportional to the current. If you got this driver, you would connect it to a microcontroller that you program to read RC signals and command the driver appropriately. You would also connect the driver’s current sense outputs to the microcontroller’s analog inputs and decide based on that when the landing gear has reached its extremes.

The SMC can respond to RC signals directly (you do not need an intermediate microcontroller to read them for you), but it does not have current feedback. It does, however, have limit switch inputs. Instead of detecting the limits through a spike in current, you could set up limit switches to detect when the landing gear is fully up or down and connect these to the SMC.

- Ben