Re: Losing Jaguars? What are the common reasons why it burns out?
 

Ironicaly, we broke just about every peice of equipment last year, including a battery, and although we had a jaguar that we though was broken, it ended up being the transmissin, so it appears our team has luck with jaguars, if not with everything else.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

My Quation ToTexas Instrument!
Who we can know if the Jaguar is working or Not?
Is there any way to do that without any Guess?

Re: Losing Jaguars? What are the common reasons why it burns out?
 

Yeah... sorry about that.

I was updating the firmware on all of them, and they were all daisy chained together. Never had a problem with it before...

Spent a good hour and a half trying to figure out the problem too. :/

Re: Losing Jaguars? What are the common reasons why it burns out?
 

We lost a total of 4 black jags this season. It seems that the beige jags are much more reliable. They're all connected via PWM's not CAN, so the CAN issue above can be ruled out. We lost two during competition for seemingly no reason, they just stopped. We're going to get the 2011 jag's replaced and swap our flight bot out with the older model jags as they haven't given us issues.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

As said by ben, we have lost a lot of black jags. i took one or two them apart to try and figure out why the kept burning out. It looked like the electronic valves (i think that's what they're called. its the 8 boxes around the central capacitor) actually melted the plastic encasing holding the in place. One of the mentors on the team told me that that usually happens when the source, gate, and drain components inside the valves get knocked out of place, which messes up the flow of electricity

Re: Losing Jaguars? What are the common reasons why it burns out?
 

We've lost 1 black Jaguar so far.

The reason for the failure isn't clear...but there were enough possible causes that it may not have mattered.

It refused to power on shortly after it rained and water got near it (but not inside it).

It refused to power on shortly after the robot it was on was hauled by truck to a practice area. So if there was some junk inside it...it had all the opportunity it needed to cause trouble.

We got no life...at all...from it once it failed and it failed from the instant of power on (so it basically just never turned on again).

A close inspection inside the unit did not demonstrate the cause.

We simply replaced it and we were fine.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

We use the tan Jags on "J-Bot", the square defense bot we practice with. We were using the 2009 wheels and traction was pretty terrible on carpet. Eventually so much static built up that when the left side of the robot hit a metal pole it discharged and the left Jag died.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

We've had very bad experiences with Jaguars, to the point that we absolutely refuse to use them. The fact that we had switched to mecanum drive this build season, and that the new black Jaguars had been released encouraged us to try our hands at CAN once more (our first experiment with it had been in '09, with 2CAN, but the Jaguar we played with failed straight out of the KoP, and was enough to warn us away from them).

We ended up spending the first 4 weeks of build season incessantly debugging persistent, temperamental CAN issues. An order of 15 blacks came in during week 2, only for us to begin CAN configuration and discover that 3 were dead out of the box. Another four failed upon connecting them to a drivetrain. Subsequent horrors include intermittent communication, a Jaguar that would work when it was the only one in the CAN and became a coupler when placed in a CAN with more than one Jaguar, Jaguars that continuously encountered voltage faults (despite no gearbox jamming or whatnot), and one with exploding blue sparks. After that, we just refused to continue with Jaguars.

Jaguars on PWM on the other hand, seem to be effective motor controllers (our clone robot this year - since it was our first try at mecanum - has Jaguars on the drivetrain, and they behave just fine).

We always cover up the electronics board when drilling, and vacuum for shavings after doing so (while grounding the robot chassis).

Re: Losing Jaguars? What are the common reasons why it burns out?
 

However, Sam, I wouldn't discredit metal shavings and static. Mounting to an exposed metal plate, over which we basically machined our robot, probably caused a lot of problems. I love blaming programmers, too - have we tried to look at other teams' codes? There are teams that do jags without a hitch. We're doing something wrong.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

At LA we lost 2 or 3 Jags. I don't remember the colors I know that at least 1 was black.

Later, we took them apart and found metal shavings inside the cases. They were probably the cause of the failure.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

Metal shavings can kill a jaguar fast!, Ways to prevent it are clean up after cutting and shield the motors while doing work on another part. But sometimes they just combust and one of the terminals can be faulty.( That's what happened to one of our brown jags.) Just have to take precautions with them due to the failure rate.

Re: Losing Jaguars? What are the common reasons why it burns out?
 

we lost 2 or 3 Jags. The reason we figure that we are not be carefully when our guys working drilling metal shavings See picture.
I open all the Jaguars clean them by ear. They worked fine
Mentor team 1946
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