Dave and Shawn, I set up battery monitor and ran the suggested test; very helpful. A full 4S 3000 mAh battery shows 16.35 V, drawing .1 A before testing. I used spin all motors at 30 seconds. At five percent, all motors start then three stop within a couple of seconds. One motor, A, continues running, not smoothly but stuttering, sometimes the full 30 seconds but usually less. Battery monitor shows about a 3 A draw. The messages pane continues to show the test is running until it times out.
If I arm the FC, all motors turn briefly, a second or less, then stop. Thereās no response to the throttle.
So clearly something is limiting current to the motors, and Iām now inclined to agree that itās a hardware fault. Unfortunately, I donāt have another ESC (yet) to try. Holybro has asked me to send them a video showing the problem (using Betaflight) and Iāll let you know their response. Thanks again.
I tried MOT_PWM_TYPE set to 0 (Normal), 1 (OneShot), 4 (DShot150), 5 (DShot300), and 6 (DShot600). Each gives much the same result; motors run for a second or a few seconds, sort of stuttering, then stop.
Thats very strange, ESCs should work as expected in the same mode they are flashed with and PWM (normal) as other modes are PWM compatible (are they???)
Try using std servos instead of ESCs. If the board is locked with PWN servo will move.
But best would be to look at signal with oscilloscope or signal analyzer.
It seems to me ESCs are damaged or miss-flashed. Preferably, the last one.
Boardsā firmware is not a case as all have the same symptoms, same with motors.
That equipment sometimes damaged. I bought a board with a broken barometer, spent two weeks soldering it and configuring it, only to find was broken. I spent a week then rewriting the driver. Finally, I sent back. Unfortunately, these things happen.
No. Weāve covered this before. Thereās no guarantee that motors will spin a certain direction unless you do some serious hardware analysis before soldering the 3 wires that connect them. You reverse based upon observation, not blind procedure.
Holybro sent me a firmware file, which I flashed to no effect. I purchased a Rush Blade 60A ESC and will try that when it arrives. Iāll post those results here.
Honestly, IMO the ESC is NOT at fault here. What happens if you run the copter with betaflight?
Motors TAB, enable BDShot Telemetry and look for the Error Counters.
Another thought, check your motors, did you use screws of the correct length to mount the motors? Some people donāt pay attention to that, especially if the motors only come with one set of screws.
You, sir, are a genius! Indeed, the motor mounts were causing the problem. These mounts are printed, as is the central hub, with 8 mm carbon tubes as arms. The 30 mm screws holding the motors protruded through the base, not touching the windings but very close. I printed some TPU pads to further raise the motors and they all spin up properly now. Thanks again to you and all the helpful people here. Now I can work on the front half of the frame, which will hold the camera.
Nice, just had to correct my own comment. I meant that the ESC is NOT at fault, just missed the NOT.
The thing with the motor screws was a common issue in the last decade when copter frames came with different size base plates.
Technically your motors are suspect to fail now because you damaged the windings.
If itās just the isolation, us a spray of PCB coating from the bottom, through the holes, so you hit only the damaged parts.
Concerning your solution, please donāt add another part that can fail, just shorten the screws instead, file, dremel, you name it. There are even pliers that can cut screws in a clean way, ENGINEER-PA-24 for example.
