Choosing a motor controller

Using Arduino Motors, Mechanics, Power and CNC
#1

Hi folks,

I am very new to electronics, so I am hoping someone can help me decide on motor controllers. My project runs at 12VDC with a max allowable current of 25A (its for a contest).

I have 6-8 motors that I would like to control in three channels (2 or 3 Left/ 2 or 3 Right/2 Vertical). The motors range from 2.5A max draw to 4.8A max draw.

Can someone recommend a suitable motor controller? Bonus marks if its cheap, rugged and available in stock (/daydream)

Or does it make more sense to have several motor controllers, each controlling a channel?

Many thanks,

Pubb

#2

Are all the motors in each channel going to be running continuously?

If so, I’d think it would be best to have a motor controller for each channel. Although some motor controllers are capable of controlling more than one motor, and this could be used to control each of your channels, so long as the current draw wasn’t too high.

There are loads of commercial motor drivers available which you could use, or you could also look at making your own using transistors, mosfets, or a relay configuration.

This one, maybe?

http://docs-europe.electrocomponents.com/webdocs/0e78/0900766b80e7875c.pdf

#3

Thanks for the quick reply! The motors in the left and right channels will be running more or less continuously and together so they provide propulsion forward/backward. The motors in the vertical channel would be running while the others were not.

Thanks,

Perry

#4

I've been looking around at different controllers, and what I'm leaning towards is:

  • forward/reverse thrust: a Sabertooth 2x12 - each would control three 2.9A motors.
  • Up/Down thrust: a Syren 10 motor controller controlling three 2.9A motors

Both of these are regenerative controllers, which I think a nice feature if the project is powered by a battery, but this may at times be powered by a regulated supply. Will the regenerative power affect the supply?

Thanks,

Perry

#5

The Dimension Engineering products are pretty good products in general (I use several of their products). However, the Sabertooth motor controllers can only control up to two motors, and the Syren motor controllers can only control a single motor.

#6

Thanks for the prompt reply! Its good to have some reassurance that the controllers are of good quality.

With regard to the number of motors, does it matter if there are 3 motors per channel if I want them to all start/stop at the same time and the amperage drawn is below the capacity? If my math is right, I'll be drawing 8.7 amps on the left channel and 8.7 on the right.

Basically, my robot will have three propellers on the left side and three propellers on the right side. Forward/reverse motion will be achieved by running all six motors simultaneously, while turns will be achieved by running three motors forward and three motors in reverse.

The three motors for vertical thrust will work the same way: three motors wired together to be controlled together. They all run forward or they all run reverse.

I am new to this so if I am missing something, bear with me :)

Thanks,

Perry

#7

Sabertooth customer service got back to me. They said that running three motors is fine, so long as the amperage isn't exceeded.

As for the power supply, they said that the power supply may/may not be harmed, so they recommended putting a battery in parallel to the controller to help mop up any current being generated by the motors.

Thanks,

Perry

#8