Our Chassis is very light and completely built with Aluminium and still the motors stall with 4 High Speed motors after 30 seconds. No issues with running 4 Low Speed with 3:2 gear ratio. But, motors stalling with 4 high speed 3:2 gear ratio.
Configuration:
All chassis motors go to Power expander. Port 6,7 Cortex to rear motors. Port 4,5 Cortex to front motors.
Any suggestions for the stall issues?
Put half of your motors on the power expander, then other half should be distributed between ports 2/9, 3/8, etc. (any combination of 2-5 and 6-9). The cortex has two PTCs built into it (one on ports 1-5, the other on 6-10), and the power expander has one. You can think of these like circuit breakers; if your motors draw too much current from one, it’ll trip. If all four of your chassis motors are plugged into one PTC, there’s a good chance that, under load, it’ll trip the expander PTC. It’s generally a good idea to split up your subsystem (such as a chassis, lift, etc.) between different PTCs and have no more than four motors per PTC. Of course, if the motors themselves are burning out, there’s not much you can do about it. Assuming it’s a 3:2 speed ratio, four high speed motors will probably not work well no matter how you wire them.
Thank you for your suggestion
In our case, do you think if we directly connect our 2 chassis motors(2-5 circuit), and other 2 chassis motors (6-9) bypassing power expander. And connect our arm(4) motors to power expander. Chassis is 3:2 get ratio with 4 low speed motors.
Our arm is not heavily used
My friends 6 motor turbo drive was constantly burning out because he had all 6 motors on the power expander. I told him how to distribute the load across the 3 breakers and now it works fine.
It’ll work, but I still wouldn’t put an entire system on one breaker. Maybe half arm, intake, and a mogo motor on your expander. It just depends on if a breaker blows, what you feel okay letting go with it.
Our configuration:
Except Chassis, everything is Alluminium
Isn’t this optimal configuration. Now that in states as it is going to be heavy defense bots, worried about tripping. Do we remove 2 motors from power expander and replace with one set arm?
Is your base chained together? (the front and back wheels)
Here’s what I would recommend:
port 2: chassis left (y-cabled)
port 3: arm (y-cabled)
port 4 (expander): chassis right
port 5 (expander): chassis right
port 6 (expander): arm
port 7 (expander): arm
port 8: mogo intake (y-cabled)
port 9: claw (y-cabled)
You can y-cable the stuff on the power expander too if you want to save ports, but you don’t really need to.
I recommend to my teams to use a y cable and run one side to the motor controller and the other side to the power expander, which then goes out to a motor controller.
In the case of chassis motors, that keeps you from having 2 motors on the same side of the Cortex.
We also generally use Port 1 & 10 for motors that benefit from faster response, so if you run a straight Y-cable, you could otherwise be loading 6 motors from a single PTC.