Re: Could a magnetic field around CIMs cause fuses to blow?
 

We'll try it, along with the magnetic field thing, but the moters seem wired right. Unless they put the wires backwards on the moter itself.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

We are certain the motors are running in the same direction in the same gearbox, each gearbox alone ran fine. However, the shorts could still be a problem, we will have to check monday.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

It won't hurt to double check it. I've had it happen and it will seem to work fine, but It really isn't. You could probably use an ammeter to check for excessive current draw as well. Good luck, hope I was able to help.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

<anouncer voice> Will team 617 discover the problem with their victors in time? Will they have to do something drastic?! Tune in Monday afternoon to see the exciting conclution to this perplexing problem! </anouncer voice>

Re: Could a magnetic field around CIMs cause fuses to blow?
 

One problem i suspect is you may be using the wrong equiptment with the cim motors. With the Atwood/CIM motors you should use the victor motor controllers between the power source and the motors (which you are using) but what should be bridging from the battery to the victor is a 40amp self resetting circuit breaker. You should only have fuses in the Spike Relays. Below you should be using the ones on the far right at the top of the breaker board for the cim motors.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

I'm pretty sure they're doing that. Regardless, the motors shouldn't draw enough to trip the breaker (or a 20 amp fuse) when it is off the ground. It probably shouldn't draw more than 6-8 amps. You should read the entire thread, the breaker tripping is the result of the problem, not its cause.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

We are using the 40A self resetting circuit breaker, but becuase theres the breaker panel and the main breaker, we say fuses because they are like the old fuses. They look like them and the almost work like them. The big difference is that they do reset and so you don't usually need to replace them.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

if infact you have 4 wheel drive and too much traction the motors will stall and the breakers will pop

Re: Could a magnetic field around CIMs cause fuses to blow?
 

It's two wheel dirve and it's off the ground so there isn't any load except the transmission and the chain.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

OK,
First things first. You first picture clearly shows a wire going to the gearbox and it looks strangely like the red lead of a Chalupa motor. This is a big no no and you will not be able to compete with this arrangement. Next you have a screw missing from motor(+) on one of the controllers which leads me to believe you using a common ground or are wiring motors in series. This is also not allowed and will not work if you plan on backing up. The motor leads on the controllers change polarity, i.e. sometimes the motor(-) is battery negative and sometimes it is battery positive. Lastly, as someone has pointed out, the mounting hardware on your controllers is touching motor(-) again giving a sneak path to frame. 4-40 allen screws work OK but tywraps work and are non conductive.
So what was happening? If all is as I surmise above, the motors on the left side are reversed so that the robot can drive forward. With the polarity reversed and the motor and controllers touching the frame, the output of the left side controllers are shorted when driving forward. The opposite condition would be the case if you were driving backward. Make the suggested fixes and try again. That is how the LEDs on the disconnected controllers were lighting when you ran the right side.
As to the question about magnetic fields...the answer is no. Yes a wire in the presence of a magnetic field may have current induced in the wire. This is dependent on two things, the magnitude of the field and the field must be changing or the wire moving. Since the motor is a permanent magnet, the field is not changing, and since the wire is not moving there can be no current induced in the wire. Since the motor leads are connected to a fairly low impedance, any induced current would be tiny compared to the motor run current.
If you have any further questions you can always PM me. I won't have an immediate answer but I will get back to you. Anyone can ask me questions and I will try to answer.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

This isn't criticism, only addressing all of your concerns.

The wire that looks like it is going to the gear box is just diconnected from anything. it looks like it is on the gear box but it is just over it. But it does look like it.

The screw is out becuase we were disconnecting things, and we pulled the wire out for that moter.

We see that, and we will check it out when we get back to check the robot. but it would seem odd that several wires would be doing the same thing and creating this problem

I agree that it is far fetched, but when isolating everything, that was about the only thing we could think of at the time. As far as no magnetic field changing, some magnet has to be moving for the moter to go. But it still seems unlikely.

Thanks for you help. All options will be considered. We will look at everyting on Monday when we get back to school.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

Believe me there is no moving magnet. All of the KOP motors have stationary, permanent magnets. The Chalupas have two large curved magnets inside the case and glued to the case to keep them from moving. The armatures move when current is applied to them but the magnetic field lines up with the filed of the permanent magnets for the most part. The brushes are doing the appropriate switching to make the fields line up. If nothing else is wrong, the hardware touching the motor(-) screw is enough to cause your problem. I think if you fix the hardware you will be much further along, if not curing the defect altogether. Remember that some controllers are reversed and they are dumping current into the frame. Try this, take you meter and with the robot power removed, check for continuity from the frame to each output terminal on all your controllers. You should measure infinite resistance for every terminal. Then move the probe to measure the +12 volt lead at the output of the main breaker. It should also be infinite. Finally, measure the input to the main breaker (off Please) and you should again have a infinite resistance. If none of these tests are infinite, find where the path exists and remove it. Let me know what you find.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

I just checked the bot. There IS a slight short with the screws in the victors. The resistance isn't infinate, but it is in the 1000 K ohms. The multimeter didn't beep when between the terminals but did between a screw and a termainal. This will be fixed, but I don't know if that was the whole problem.

I rechecked again with someone looking and found that the screws arn't conducting to the terminals. I found that while the wires are distint and not crossed, all of the positive red wires are conducting for each other. I tested from the breaker panel to the victors and all of the red are conducting from each part on the panel on the 40A fuses. I don't know how this works. I can't find any grounds anywhere near the victors. The red wires arn't connected tot he balck wires, but all of the black wires are connected together like the red ones. We are going to re-wire it to track down the culprit. If you have had trouble like this or know what is happening, this tr4ead is still going until there is a cure. In other words, We need more help :D

Re: Could a magnetic field around CIMs cause fuses to blow?
 

Voodoo diagnostics is a tricky business, but I think I have a theory that fits your facts.

I assume your software is controlling two motors with a "right side" pwm signal, and the other two with a "left side" pwm signal. If you have one left side motor being controlled properly but the other one controlled with the right side signal, they will oppose one another when you try to turn, and you will trip a breaker if you're lucky. Same with the right side, though it sounds like you've never gotten it upset enough to actually trip a breaker, instead just having a motor being backdriven against its will.

If you remove the fuse for the wrong-sided motor, that motor will be turned by the other one on the same gearbox, and you'll end up with the Victor getting powered by the generated current.

You can either 1) disconnect all your motors and watch the lights on the Victors as you go from neutral to full throttle to full turn, and see which ones respond; or 2) double-check the code, the pwm cables, and the motor wires to make sure they all agree.

Since you insist your wiring is correct, your software is at fault, but it'll probably be easier to correct the problem by changing which pwm outputs your Victors are plugged into.

Re: Could a magnetic field around CIMs cause fuses to blow?
 

We removed the fuse for both moters on the one side. Somehow, the victors, suposedly disconnected from anthing when we removed the fuses, would still work when the other side, still connected, went. In testing the connections this morning, I saw that all of the reds were connected somewere. Looking at the wireing revieled that it looked OK. The wires arn't grounded to the frame or anything else. Black wires were connected to themselves but the Black and Red wires were isolated from each other and the frame.

Uh.. Should I be getting contentutiy through the breaker Panel with fuses out? I put one lead on the battery termainal and the other on a termainal for the moters. The resistance was great but I though it should be infinate.