victor 884 blowout

[Cody Carey]

About five days before shipping, we just happened to glance at the electronics and notice that two of the 884s that were on two entirely different motors were blown, one to a window and the other to a CIM. we replaced them with red-sticker 884s from last year and everything was fine until the next day when we blew ANOTHER new 884. We checked all the regulations and our wiring was done to specs. has anyone else had this problem?

[dez250]

Originally Posted by Cody C

About five days before shipping, we just happened to glance at the electronics and notice that two of the 884s that were on two entirely different motors were blown, one to a window and the other to a CIM. we replaced them with red-sticker 884s from last year and everything was fine until the next day when we blew ANOTHER new 884. We checked all the regulations and our wiring was done to specs. has anyone else had this problem?

Were you doing any work around them where metal chips could of gotten into the FET's or casing. If this could have occured then that most likely is your answer, you shorted them out. If you have the Victors still and could get photos of the damage that is visable someone here could get you the most likely answer.

[Cody Carey]

We mounted the electronics on lexan, and then brought the electronics to the finished frame after blowing them down with compressed air, so I'm fairly sure there were no metal shavings. The crazy thing is that there is no visable damage, they just stopped working

[Bharat Nain]

Originally Posted by Cody C

We mounted the electronics on lexan, and then brought the electronics to the finished frame after blowing them down with compressed air, so I'm fairly sure there were no metal shavings. The crazy thing is that there is no visable damage, they just stopped working

Make sure it is wired up correctly including PWM cables.

[Cody Carey]

Ok, I am VERY fairly sure that we did everything by the book, and as soon as we wired up last years controllers instead, they worked. It just kind of seemed like a weird thing that it was only the new 884s.

[dez250]

Originally Posted by Cody C

Ok, I am VERY fairly sure that we did everything by the book, and as soon as we wired up last years controllers instead, they worked. It just kind of seemed like a weird thing that it was only the new 884s.

OK I think i know your problem. The new Victor 884's have a longer and harder to seat pwm socket. When you get to your robot at your first event, take the pwm cable out of the one that isn't working now and check to see if the pins are bent. If they are it means they weren't aligned with the socket and got bent while inserting. If they aren't and the Victor doesn't respond, just flashes orange then try to re-seat the pwm cable. These new Victors take a little more force and patience to seat the pwm cables properly.

[Cody Carey]

OK, thanx! I'll try to hook the "blown" 884s up tomorrow on our test bot, and if it works you'll hear from me

[sanddrag]

What makes you say they are "blown"? Was there fire, smoke, sparks?

[Cody Carey]

Well, when I say "blown" I mean cease to work, or messed up
you know, like if someone had "blown" it, or screwed up.

[sanddrag]

Does the indicator light show anything at all?

[Cody Carey]

On two of them, no. but on the other one it was flashing as though there were no pwm input.

[FusionDude364]

Originally Posted by dez250

The new Victor 884's have a longer and harder to seat pwm socket.

Yes, PWMs are very irritating to deal with anyway, but the new victors definately make it harder. Also, I dont think your problem is this extreme, but try checking the motors. We rewired our last year bot at the start of this year, one reason being one side kept blowing victors (we went through about 4). The problem wound up being the cim motor it was connected to. We replaced the motor and havent had a problem since. Again, I doubt your problem is this severe, but this is worth checking if nothing else works. I would definately check the PWMs first though.

[Al Skierkiewicz]

Originally Posted by Cody C

On two of them, no. but on the other one it was flashing as though there were no pwm input.

Cody,
The LEDs pretty much tell all. Let the controller talk to you and it will tell you what is wrong. A flashing orange indicates the PWM signal is missing. A steady orange indcates PWM is present and a "zero" speed is being received. No LED indication and no motor moving indicate the power to the controller is missing, check that the breakers are in place.
It looks like about 90% of the controller failures are PWM cable seating. On the new controllers, all but about 1/8 of an inch is inside the collar when the cable is fully inserted. If more than 1/8" is showing, it needs to be pushed in further. Visual inspection to determine blown FET cases, account for the remaining 10%. When a FET blows there is no doubt of the problem. One or more of the plastic bodies will have cracks, chunks blown off or black arc marks where the damage occured. These failures usualy have a burned odor as well. Damaged controllers can be returned to IFI for repair.

[mtaman02]

I witnessed a V884 Blow out but the funny part was only part of it went. The Device that was being used refused to go in reverse but it went forward just fine the only problem is is that it refused to stop once you got off the sticks. =) needless to say after about an hour of looking through the programming and looking at the things that were being used (Motor, Wiring etc..) it was finally determined that a speed controller went. Those involved in the troubleshooting as well as myself are still stumped as to how the V884 blew.



One idea of how it happened is that the V884 when it was going forward (while no one was paying attention) the little stopper on the device we were using went passed where it had to be and couldn't go any further and the speed controller just overloaded or something and blew out part of its function - I don't know if this could be true or not.

The other idea is that something got into the speed controller, a piece of metal perhaps and shorted things out. Kinda hard to believe espicially the team involved is fairly a safety conscious team, let alone a clean team (nothing loose in the robot to cause unwanted behaviors, let alone no robot welding, drilling or cutting while there are electronice in place unless covered properly)

[Al Skierkiewicz]

Originally Posted by mtaman02

I witnessed a V884 Blow out but the funny part was only part of it went. The Device that was being used refused to go in reverse but it went forward just fine the only problem is is that it refused to stop once you got off the sticks.

What you describe is a classic case of miscalibration. Remember that the controller when it is in calibrate, determines the full forward and reverse of the joystick travel and the at rest position and then stores them when the calibrate button is released. If the robot drives forward with the joystick and then slows down but doesn't stop when you release, try recalibrating. Failure mode on the controller could be no movement in either direction if the FETs go open or full power in one direction if they FETs short. If all FETs short there is a brief period where there can be smoke, fire, arcing and/or the sound of cracking plastic.