Hi there!
Not sure if there are still people around that started this thread, but there was a lot of good stuff done here!
I’m building my own thing (of course) and have some trouble with it. Maybe someone here might be able to help.
This is the rig; currently only dealing with the Roll axis.
I’m controlling the DC motor with the BLD-300B driver through Arduino Uno (R4). The motor is 57BLS03 which on 36V should give about 90W. The driver is rated to 300W so should also be plenty.
The motor has hall sensors, which I piggy back on to the arduino and track movement. Works well without any issues.
Except, sometimes the change in rotation direction will cause the motor to stall and will not move until I nudge it in the right direction.
The calibration for far-roll ends logic is:
- Set PWM duty cycle to small, ~15%.
- Initialise the hall sensor.
- Set PWM duty cycle to achieve desired speed (let’s say for the example, 30%).
- Rotate CW or CCW until the switch is hit.
- Motor brake is applied & Engaged pin is disabled.
- Wait few milliseconds.
- Release the brake, engage the motor.
- Set rotation oposite to what was before (there are some interim states here, but are irrelevant).
- Set PWM duty cycle to 90% until the movement is detected. (PWM wave)
- Set PWM duty cycle to desired, 30%.
*…
- Set PWM duty cycle to desired, 30%.
So for now I’m trying to get this thing reliably swing from one end to another, at relatively low speed.
It doesn’t work reliably. Quite quickly the motor will stall at one of the end positions, after the rotation direction has been changed and set to new one, and all brakes are released. At that time, the power supply is drawing ~1A only. This was surprising to me, as I expected to see higher numbers. That was the reason I implemented the PMW wave function, but even with 90% duty it won’t budge.
When giving it a slight nudge the rotation happens quickly.
In general, even with the higher PWM duty cycles, it feels extremely weak when turning the gear.
I have checked the cabling, the power supply is pretty good and never had any issues with it…
My assumption was that it would be hard to fight this motor, given it’s power and gear ratio, but it doesn’t even move the gears on it’s own.
I have another controller and a motor in transit for the pitch axis, I guess I’ll see if anything is defective. But in the meantime, any help, troubleshooting or even crazy ideas are more than welcome!