Jaguars failing

[Bruceb]

So, does anybody know if the jaguars were improved or are we going to have the same extremly high failure rate this year?
Bruce

[Tom Line]

Bruce, there are a number of posts discussing the failure rate of the jaguar.

For instance, here:
http://www.chiefdelphi.com/forums/sh...fai lure+rate

In that post they discuss a total of 88 jags to date. When you consider that close to 4000 jags were shipped to teams just in the kit of parts, I'd wager the failure rate including all jags sold is well below 1%. I think I would argue with your "extremely high" statement.

There will be a new black jaguar that has been discussed repeatedly both on this forum and the usfirst.org official beta forums that has some modifications to improve the durability further.

[rihan.nasser]

hey

this from the first team of Australia
we would like to know anything vaubleable info on the Jaguar motor





thank you


3132

[Bruceb]

Interesting note on the failure rate. We lost 3 ourselves and everybody I talked to at the Milwaukee regional lost at least one.
Bruce

[Chris is me]

Originally Posted by Bruceb

Interesting note on the failure rate. We lost 3 ourselves and everybody I talked to at the Milwaukee regional lost at least one.
Bruce

Not us.

I think the reason people think the failure rate is higher is because failed Jags came bunched together in the same kits. My team got the "good batch" last year.

[Al Skierkiewicz]

Tom,
Can you give us a good way to know if the Jaguars have the latest software updates? The KOP box says rev A on it, does that imply a certain level of software or hardware revision?

[jhersh]

Originally Posted by Al Skierkiewicz

Tom,
Can you give us a good way to know if the Jaguars have the latest software updates? The KOP box says rev A on it, does that imply a certain level of software or hardware revision?

The way to tell is by plugging it into CAN. If using a black jag as a bridge, you can use the bdc-comm utility to query the version. If you intend to use the Servo PWM interface, then you don't need to upgrade the firmware.

As for hardware revisions, they are either black or gray plastics. All gray jags are the same hardware inside.

[Tom Line]

Originally Posted by jhersh

The way to tell is by plugging it into CAN. If using a black jag as a bridge, you can use the bdc-comm utility to query the version. If you intend to use the Servo PWM interface, then you don't need to upgrade the firmware.

As for hardware revisions, they are either black or gray plastics. All gray jags are the same hardware inside.

Thanks Joe! Unfotunately I'm working afternoons and midnights right now. Getting home at 4am is killin' me, and putting a crimp on responding to chief delphi questions in a quick manner is a bit tough.

[Peter Randall]

It has started again. We have already toasted two Jags from last year. We purchased a number for last year's bot and removed them all from the robot after toasting 4. We just built a prototype drive base and in two days have smoked 2 of the "replacements" we got last year. Same symptom, it only loses one direction after issuing the magic smoke. I really wanted to move to CAN, but I CAN'T if I CAN'T rely on the Jags. Has anyone smoked a Black Jag yet???

PGR

[Tom Line]

Originally Posted by Peter Randall

It has started again. We have already toasted two Jags from last year. We purchased a number for last year's bot and removed them all from the robot after toasting 4. We just built a prototype drive base and in two days have smoked 2 of the "replacements" we got last year. Same symptom, it only loses one direction after issuing the magic smoke. I really wanted to move to CAN, but I CAN'T if I CAN'T rely on the Jags. Has anyone smoked a Black Jag yet???

PGR

Peter, are you covering the open connectors on the jags with tape, a plastic jumper, or something else? It's been shown that direct static to the open jag connectors can cause issues.

Have you tested your frame to see if you're running electricity through it?

Are you mounting your electronics on a conductive or a non-conductive surface?

[Al Skierkiewicz]

Tom,
The direction failures are attributable to one of the power FET gate drivers shorting. I don't remember if the cause of the failures was ever found or reported.

[jgannon]

Originally Posted by Tom Line

In that post they discuss a total of 88 jags to date. When you consider that close to 4000 jags were shipped to teams just in the kit of parts, I'd wager the failure rate including all jags sold is well below 1%. I think I would argue with your "extremely high" statement.

Considering that the vast majority of teams don't post on CD, I'm certain that far more than 88 Jaguars have failed, and consequently that the number easily exceeds 1%. Definitions of "extremely high" may vary, but I don't recall a single report of a Victor failing for any reason other than negligence, so in comparison this seems very troubling.

[jhersh]

Originally Posted by jgannon

Considering that the vast majority of teams don't post on CD, I'm certain that far more than 88 Jaguars have failed, and consequently that the number easily exceeds 1%. Definitions of "extremely high" may vary, but I don't recall a single report of a Victor failing for any reason other than negligence, so in comparison this seems very troubling.

The 88 figure came directly from TI, I believe. Meaning that's how many they had returned by teams. That has nothing to do with CD.

And speaking of negligence, in the top two causes of failure, one was negligence... and that was removing the screws from the jaguar power terminals which leaves metal shavings inside the case. The new black jag does not use retaining screws since people are going to remove them even if it will cause a failure.

[jgannon]

Originally Posted by jhersh

The 88 figure came directly from TI, I believe. Meaning that's how many they had returned by teams. That has nothing to do with CD.

And speaking of negligence, in the top two causes of failure, one was negligence... and that was removing the screws from the jaguar power terminals which leaves metal shavings inside the case. The new black jag does not use retaining screws since people are going to remove them even if it will cause a failure.

Mea culpa. Thanks for the info.

[Racer26]

That figure of 88, EVEN if its accurate as to the number of units that LM/TI received back still doesnt really tell us anything.

There are LOTS of teams, i'm sure, who just had one blow up and never thought to contact LM/TI.

I know 1075 used 6 jags on our 2009 bot, and we had no fewer than 2 jags fail on us. Both in the same way, a plume of smoke and upon closer inspection, toasted FETs. We're very careful about filings getting into speed controllers, over the years we toasted a few Victors... including an entire robot's worth of electronics when the ground clip fell off the robot during welding. Ever since then welding is done without electronics on the bot.

My count says 2/8, thats a 25% failure rate. There seems to be no shortage of the well known names around here with similar numbers. That sort of leads me to believe that the numbers are bigger than it would seem from what LM/TI tells us.