I hate Jaguars!!!

[implosionprez]

We have had trouble in the past (in 2009) having Jaguars burn out on us. We used Victors last year because of this. This year, we put the Jaguars that came in the KoP on the robot, and today, one of them gave out!! Why do they give out like that? Are they just junky, or is there something wrong with the way we have them connected? Is anyone else having trouble with the Jaguars this year?

[wilsonmw04]

Originally Posted by implosionprez

We have had trouble in the past (in 2009) having Jaguars burn out on us. We used Victors last year because of this. This year, we put the Jaguars that came in the KoP on the robot, and today, one of them gave out!! Why do they give out like that? Are they just junky, or is there something wrong with the way we have them connected? Is anyone else having trouble with the Jaguars this year?

We've used Jags since the first year we had them. We've only had one go down on use the first year and have been using the others consistently(3 years now) since. We bought 4 new "black" jags this year for our 'bot. The only thing that I don't like about them is the fit of the PWM's. They slide out way too easily. I'm used to a more snug fit guess. We hope that using the plastic wire tab on the side will keep them in place.

[jsasaki]

we have 20 jags and none have gone yet

[ratdude747]

my current team had a box 3 bad jags. when I was done (opening and removing metal bits), the box was empty. all 3 ran fine after a cleaning.

make sure that you didn't get any metal shavings in there...

[bmxer51]

Metal shavings are a big thing that cause them to go out. My team has broken at least 8 however we have an electrical engineer that has replaced a few transistors and they work now. Although we can't use them in competition (because they have been modified) they are perfect for use on our practice bots

[emusteve]

As long as he replaced the FETs with like parts (same part number), that's a repair, not a modification. I wouldn't think there would be a problem with that. I've repaired both Spikes and Victors in the past.

On another note, We've had our share of problems with the Jaguars. They don't seem to be as "Hardened" as the Victors. Static seems to be the vulnerability.

Steve

[Zuelu562]

Yea, I hate jags too. Dealing with them in the pit in 2009 was so annoying we switched our (quite literally) destroyed jag with victors. Our current setup will be 2 "black jags" (nicknamed by myself and a friend "Panthers") and 5 victors.

[bladetech932]

Love the capability! hate the reliability.

[Joe Ross]

Originally Posted by emusteve

As long as he replaced the FETs with like parts (same part number), that's a repair, not a modification. I wouldn't think there would be a problem with that. I've repaired both Spikes and Victors in the past.

The rules this year do not make any distinction between a repair and a modification of a control system component. Any disassembly is illegal.

We've used 16 jaguars over the last 2 years with no failures. Over that same period, we've used 10 victors and had 1 failure.

[Sovietmagician]

We tried out jaguars in 2009, decided we did not like them and used Victors. Then this year we decided to give those jaguars another shot. We got a shipment of the black jaguars and a fair amount of them where DOA. As if that was not bad enough one jaguar inexplicably stopped working yesterday and then at the end of our meeting a different jaguar caught fire. The jaguar glowed blue with electrical sparks and then a plume of smoke erupted from the inside. we checked the wiring to the jaguar everything was normal, our jaguar just decided it would fail catastrophically... I HATE Jaguars

[wilsonmw04]

Originally Posted by Sovietmagician

We tried out jaguars in 2009, decided we did not like them and used Victors. Then this year we decided to give those jaguars another shot. We got a shipment of the black jaguars and a fair amount of them where DOA. As if that was not bad enough one jaguar inexplicably stopped working yesterday and then at the end of our meeting a different jaguar caught fire. The jaguar glowed blue with electrical sparks and then a plume of smoke erupted from the inside. we checked the wiring to the jaguar everything was normal, our jaguar just decided it would fail catastrophically... I HATE Jaguars

sounds like you have a metal shaving rich environment...

[Sovietmagician]

Originally Posted by wilsonmw04

sounds like you have a metal shaving rich environment...

Maybe that is the case on the jaguar that died with out warning. however the one that started smoking and catching fire was on a practice drive train where no one would have any way of getting metal shavings into it because there is nothing to work on above the jaguars. Unless one of our team members decided to sprinkle our electronics with metal shavings, I just don't see how metal shavings got into that jaguar.

[ProgrammerMatt]

We have experienced two Jaguars show the "magic smoke" in other words burn out, we have come to figure out that Jaguars are extremely sensitive to metal shavings/ dust make sure you cover them when your drilling near or around them thats how they usually go bad.

P.S If you use CAN be careful because when one of our Jaguars burned while we drove our robot one motor kept driving even after you E-stop it we had to chase it down to turn it off luckily it was only at like 25% power.

[gustagoose]

We, 3172, have had significant issues with jaguars in our short existence. At Greater Kansas City Regional, early last March, we had two "blow-outs". We had a third "blow-out" during off-season community outreach, and a fourth during a test. With this fourth jaguar, we were not even enabled. We heard a quiet but very high pitched squeal emanating from the vicinity of the jaguar's 20 amp fuse. A slightly louder click sound pulsated through the, 14 gauge I believe, wire obviously connecting the jaguar with the main power board. We flipped the breaker, and turned it on again and got similar results. As a second year team, we simply don't have the funding to purchase jaguar after jaguar after jaguar. We have checked wire gauge, voltage, current, fuse, ground, connectors, etc. Nothing. Any advice or ideas would be splendid!

[Phalanx]

There definitely are arguments for both cases, however we are using a MIX of Jaguars(4) and Victors(4) this season. We are ONLY using the Victors due to space limitations otherwise they'd be Jaguars. Even that could have been avoided by better planing and design in the early stages.

Victors are a proven quantity with a solid track record. However, I fully expect them to do be disallowed in VERY the near future. Hence the migration to Jaguars and CAN.

Jaguars in their early stages (Gray/Brown) had some design flaws and some manufacturing defects, making them somewhat unreliable. That has been addressed with Texas Instruments purchase of Luminary Micro and the new BLACK Jaguars.

The Older Jaguars:
We have 4 Jaguars(Gray/Brown) running on a basic practice/test frame for 2 years, and they haven't failed yet.

I did have 1 Gray/Brown Jaguar fail with the typical meltdown of the Fairchild component when I attempted to use it this year. The other remaining Gray/Brown Jaguar is unused. As such, they are now all BLACK Jaguars.

The advantages to Jaguars and CAN are enormous compared to Victors & PWM besides being cheaper:

1) CAN wiring, is cleaner, easy to make with a standard teleco crimping tool, the plug in and don't fall out like PWM. CAN is also highly noise and interference resistant/tolerant unlike PWM.

2) Jaguars "built-in" support for Encoders, Potentiometers and Limit Switches and PID and software control of break/coast without additional wiring.

3) CAN Networking/Jaguar, you can...
a) Monitor the health and status of each device, it's voltage, it's temperature, the motors amp draw, etc...
b) You can program for Voltage Control, Current Control, Position Control and switch between them dynamically.
c) You can synchronize commands across multiple Jaguars.
d) List the goes on...

While, I'm not a huge fan of Jaguars due to their early history, I do see the future and benefits of them long term going forward.