Motor Controller Issues

[crollison]

Rookie and I hope easily fixed issue.

Trying to get the basic drive train going. Using labview and loaded up the base cRio project and from what I can tell it has the default program to drive two motor controllers using arcade joystick. The problem I have is that one of my Victor's doesn't seem to be working correctly. When the program is initialized, the motor runs full power for about .5 seconds, then sporadically when the joystick is in different positions it will run full power or nothing.

I have switched pwm ports, and motors on the motor controllers. The same thing happens so I can assume that it is not programming since it didn't switch to the other motor when I switched pwm ports. I tried calibration, but that didn't do anything different.

Anybody have any ideas? I intend to swap out the one victor for the jaquar even thought I doubt that is a great scenario with drive motors controlled by two different types of controllers.

Thanks.

[Alan Anderson]

Sporadic PWM outputs can be a sign of power problems on the Digital Sidecar. Are all three of its power LEDs lit brightly?

[crollison]

Yes they were, swapped out the victor for a jaguar and now running smooth. Think maybe I just got a bad part.

[nathan_hui]

More than likely. Unfortunately, the victors do have a bad track record at 2473 (fires, other failures), so they've been relegated to cold storage.

[IndySam]

Originally Posted by nathan_hui

More than likely. Unfortunately, the victors do have a bad track record at 2473 (fires, other failures), so they've been relegated to cold storage.

Sorry to hear about your luck with Victors but I think that their track record over the years is indisputable evidence that Victors are the most reliable speed controllers FIRST has ever had.

I don't think we have ever had one fail (other than OE) in our history. They are so good I don't think we have purchased one in three years. They just keep on ticking. We still have red-lable ones.

[Ether]

Originally Posted by IndySam

Sorry to hear about your luck with Victors but I think that their track record over the years is indisputable evidence that Victors are the most reliable speed controllers FIRST has ever had.

I don't think we have ever had one fail (other than OE) in our history. They are so good I don't think we have purchased one in three years. They just keep on ticking. We still have red-lable ones.

So therefore, Nathan, you might want to look into why your team's experience has been different. You might gain some very valuable insight about design of systems using motors.

[Paul Copioli]

To follow up on what Ether and Indy Sam have said, we simply do not get Victors returned to us nor do we get many phone calls on the Victors. The few we get back are due to user error.

Even if you try to pull too much current from the Victor, the failure mode is desoldering of the FETS from the board.

Please contact our technical support line if you truly have failed so many Victors.

[nathan_hui]

When I get back to our lab, I'll spend some time testing the Victors (that we have in the closet and suspect of trouble) to get some numbers in order to prove to myself and the team that the Victors are good. It may be that we abused them too much (we end up abusing quite a bit of stuff, only because some of us in our young age lack discipline...). Maybe we're lucky (none of our Jaguars have failed on the robot. They've failed on the lab bench, but then those were being subjected to something else entirely...). I'll get back to this problem in a few months. Sorry my problems hijacked the thread.

[apples000]

Our team has found Victors to be incredibly reliable. We have about 10 victors that we purchased over 10 years ago and they all still work. The most likely failure is getting metal dust inside or connecting the power backwards.

[JVN]

Please get in touch with our support folks so they can help you diagnose the problems you're seeing. support@vexrobotics.com

We have people standing by to help ensure you have a quality experience.

-John