I am working on the power system for a large (6' wide x 5' long) rover. The motors are 4 brushed DC motors with 60 A draw. In the past I have used the sabertooth motor controller and thought about using 2 60 A controllers (one for each side). Is it possible to use 2 sabertooths with one pixhawk? or any suggestions on a better way to set this up with only 1 motor controller?
The motors and batteries I have to use are listed below.
There should be no problem. How are you going to steer?
I use Skid Steering and it works perfect. I have Sabertooth 2x25 and connect two DC motors in parallel on each side.
Of course you can use 2 Sabertooth and do the same.
You can't. Skid Steering only uses the Roll channel input for turning and the Pitch channel input for forward/backward speed control.
Each side motor pair is driven by one ESC so that you have one ESC for each side that receive the Pixhawk Skid Steering servo outputs.
I believe that the Castle Creations Mamba line of brushless monster ESCs can be run in a brushed mode, though at lower power operation.
But why not connect y-cable or simply connect two inputs per one output.
I connect two motors per Sabertooth output but as you need more power you can connect one output to two sabertooth inputs per side. The motors will run at the same speed although they will not produce exactly the same power.
My rover runs so smooth and turns so nice. The bigger concern is the mechanical design. To turn nice the distance between the wheels, on the same side, has to be small and the width of the rover has to be quite larger than this distance. Otherwise it is very difficult to turn on a rough surface. On a more flat surface, like a road, this is less critical.