Issue with CIM/Jaguar

[seg9585]

All,
We are having a strange issue with our shooter motor (single CIM, direct drive to two belted plastic wheels).
We use a toggle button to set the motor to full power to run.

Initially, the motor starts running, but after revving up for ~ 1 second it stops, the Jaguar blinks red + orange (note: the "positive" power, green, is the intended power direction).
The motor stops for a few seconds, then powers back on for a second and repeats this process. We don't have any code that is disabling the motors (another joystick button sets the value to 0, but this is never pressed in this test).
This pulsing happens for ~30 seconds. After this time, the motor powers on, revs to full speed, and stays on as intended (almost as if the motor has to warm up). Toggling on/off works perfectly after this.

We swapped out Jaguars (with a brand new one) thinking that may have been causing the issue, but the issue still persists.
When we apply power to the motor directly via battery, it works perfectly.

My guess is an overcurrent (that the Jag is protecting against), but why would the motor behave normally after attempting to run for ~30 seconds?? We hooked up an ampmeter to the motor while running and nothing seemed unusual. Running 2 lightweight plastic wheels off a motor that has little resistance (ie we're not stalling it) shouldnt cause this.

Any tips?

[Mark McLeod]

Have you upgraded the Jaguar firmware to v107?
It was supposed to alleviate the over current protection issue on the Jags.

The problem is that the CIM is by definition at stall when it first starts up, and once the Jag begins faulting, further faulting gets easier, so to speak. Once the CIM begins moving or gets moving fast enough, then it's no longer drawing stall current.

[Kevin Sevcik]

Try a different Jag and see if the problem remains. Your current one might be flaky.

If you still have the problem with a different jag, there's probably some friction or resistance somewhere that's causing you to draw too much current. Running the wheel in does a few things to reduce your current draw. Namely, it warms up any grease in your system, wears down anything adding friction, and warms up your motor, increasing its resistance. All of those things could be combining to drop your start up current draw to just below the fault level.

[seg9585]

Kevin -- Yes I've tried 2 Jags, one came in the 2012 KoP (don't know the firmware version) and the other in the 2013 KoP.

Would using a Talon avoid the overcurrent issue?
I can check the firmware version, although I've never had to do this before...

[Kevin Sevcik]

Kevin -- Yes I've tried 2 Jags, one came in the 2012 KoP (don't know the firmware version) and the other in the 2013 KoP.

Would using a Talon avoid the overcurrent issue?
I can check the firmware version, although I've never had to do this before...I think even the 2013 Jags have v101 on them. A Talon would likely solve things if you had one available. Ramping up your voltage a little slower would also solve things, though your shooter would spin up a little slower.