We own 2 separate V5 clawbots. We run them in manual with the controller. Within the past week BOTH robots have started having trouble with lifting and lowering the arm. In the middle of a run, it will all of the sudden only the arm will quit working. Everything else works, just not the arm. During a recent practice it happened to one of the robots & the motor did feel hot. I replaced the motor & one of the gears. Today, the kids competed and the arm did the same thing.
Run down of today
-They did a test run & everything worked fine.
-They powered down & waited at least 20 min for their turn to compete
-They powered up when the judges got there &
as soon as they powered up it wouldn’t lift. All of the other motors worked fine. It’s only the arm that wouldn’t work.
-They tried powering down & back up. Nothing worked.
-5 minutes later when I was able to see them, we powered the robot up and it worked fine.
It’s weird to me that we have had these robots for over a year and are only just now experiencing this problem & the same problem is happening to both of them. Nothing is obstructing the arm. The motors have been replaced.
Help! I have 2 more teams that need to use these robots in the next couple of days to compete and I don’t want it to happen to them.
check the brain event log and see if there are any messages about the motor overheating.
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I’m not seeing any messages from when motor 8 went out during the competition. That run looks completely normal.
I did see several messages prior to the competition that motor 8 and motor 3 reached heat levels 1 & 2. I had replaced motor 8 just prior to the competition, so that makes me think it’s the port not the motor.
I have borrowed a brain from another school and installed it on our robot. I’m hoping that change will keep us safe for the next 2 competitions.
Please let me know your thoughts on this & if there’s anything else I can do to prevent this from happening to the next two teams. We compete tomorrow.
If the motor is working too hard it will overheat and its firmware will set an error and reduce available power, that’s what you are seeing with motors 8 and 3 in the event log.
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There were no error messages/heat messages the day of the competition to explain why the arm wouldn’t work. In addition, they only did a quick test run that wouldn’t have caused the motors to heat up and had then powered down for a good 20-30 minutes. Meaning the arm problem occurred when heat levels were fine.
Soooo, that brings me to….
Thinking it’s a port problem not a motor problem.
Could the repeated error/heat codes in the past have caused damage to port 8 not the motor? I ask this because I had replaced the motor prior to competition.
Will you provide some photos of the robot?
My first questions would be:
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What gear ratio are you using for the arms?
If the ratio is too low (or not using gears at all), the motors have to work harder to lift and hold the arms, which leads to overheating. Increasing the gear ratio can reduce the strain on the motors.
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Are the arm motors set to Hold mode?
In Hold mode, the motors constantly apply power to maintain position, even when stationary. If the arms stay raised for extended periods or under load, this can quickly heat them up.
I did a practice run today with new motors and a new brain and it’s still giving me the overheating signal on port three the claw and Port eight the arm. What can I do to keep the motors from overheating? It’s just a basic claw box build and we’re only running it for a few minutes.
Can you take a picture of the back of the robot showing how the gears and bearing blocks are put together?
