We were driving around today, and notice that our arm is pulsating when under full power from the OI. We originally thought it was the motor, but it’s the Victor. The power seems to be pulsating. When under full power forward, they blink from orange to green. Any ideas as to why its doing this? I’ve never seen this before.
I would verify that its not some bug in the code. Also, You may find that a loose PWM cable is the culprit (it either may be not fully inserted, or the legs might be loose inside the housing for the cable.
Also, how is your battery and backup battery. Could it be that your battery is low and causing the RC to reset?
-Mike
A Victor alternating green and yellow could be a symptom of an intermittent pwm cable, but you’d probably notice that at something besides full power. It sounds like it’s being commanded to neutral. I assume this motor is being controlled with a joystick? If so, I suggest you use a dashboard monitor program to verify that the joystick isn’t getting flaky at its extreme position. An open circuit is detected by the OI and sent to the RC as if it were a joystick at neutral.
We recently had a similar glitch and traced it back to a low battery on our USB chicklet. All of the sudden our perfectly calibrated Victors started pulsing intermintently, so we recalibrated the crazy ones and they still pulsed. Then the driver noticed the chicklet’s led was cycling on and off. So we replaced the chicklet battery and the previously recalibrated Victors were messed up yet again. When we recalibrated (again) everything was good.
Moral of the story?
If your robot starts acting silly for no good reason (i.e. same program that has always been on there), then check ALL of your batteries; backup, 12v, chicklets…all of them.
Our team had the same problem. It ended up being a programming bug. Easily fixed by our programmer who fortunately knew what he was doing.
So we did this:
Checked Battery, Backup Battery
Replaced PWM
Checked Code (it’s programmed in EasyC so I don’t see how it can be a code error)
Replaced the Joystick
…and we even replaced the Victor with a brand new one fresh out of the box. We checked all the wiring, everything looks fine. It’s powering the small black window motor running off a 30A breaker. It’s not a torque or friction issue, the shaft is heavily supported with a bearing block on the other end. When I took off the chain and just ran the motor by itself, it still pulsated. I even disconnected the wires from the Victor and jumped it right to a battery we had lying around and it ran fine.
I’m seriously stumped here.
Justin,
Although the change in color is not explained by what I am about to tell you, remember that the motor itself has a thermal cutout internal to the motor.
The next step is to place a VOM on the input terminals of the Victor to insure you have a solid 12 volts at this point when the motor is under load.
I would also try running the default code for that motor (all others disabled) and see if in fact the code has a problem. I believe the LED is telling you that the PWM is changing but I don’t know how the Victor reacts to bad power under load. The best method to find the problem is to eliminate all the variables.
i had the same problem last season. it turned out to be the pwm cables, they wernt connected correctly.