Dead JRK

A moments silence... I killed one

The large chip now gets very hot as soon as it is connected to power and the unit emits a buzzing sound.
Can these be replaced/repaired? I have read posts where people have them replaced by pololu at half price, how do you go about that?

I don't know if there is a special "trick" involved in getting them to replace it at half-price or not but here is a link to their support page and what they have to say about issues with their products.
http://www.pololu.com/support

send an email to pololu explaining how you wired it up to nuke it, and they MIGHT give you a 1/2 price replacement.
But how did you wire it up anyway? Can you tell us?

Maybe you should call them instead! Then in the middle of telling them what happened you could start crying! Maybe the person will have more sympathy for you! Or better yet, it would probably be more convincing if you have your wife or girlfriend call (cry) for you! lol

Pololu know what we are doing with them and how we abuse them......
Still , email and ask.
We have proved to pololu how hard these little bastards can be driven. Even they are stunned.

It was wired correctly, but there could have been a strand shorting across the inputs (trying to get decent sized wire into the blue connectors is hard!).

I had taken my test rig apart and reassembled it and was doing the test motor direction function in the pololu configuration utility when it happened. I think there may have been an internal short within the motor it was hooked up to or something like that. The motor had always worked well previously, and the other side (motor and controller) still seem to be ok. Im using heatsinks and fans.

I'm also driving pretty large motors, they draw up to 60 amps but I'm hoping that in a simulator the loads will be far less. Am I asking too much of the JRK?
http://www.warn.com/adventuretouring/RT15_winch.shtml

yes you are asking too much. JRKS run 49 amps at 6 seconds and then shut down.
Considering simulators run at stall amps which can be continuously high, you should not be looking at more than 40 amps continuous. Less is better.
The motor is rated at 300 watts so thats getting near the limit of a jrk, especially when the motor will be under stall current, which is usually 2.5-3 times higher than rated.

I was attempting humor above, kind of! When I burned up (literally burst into flames) one of my sabertooth 2x50's I felt like crying at $200 each! But they are guaranteed against almost anything that you could do to them under normal setup and operation because they are supposed to be protected (probably not spilling water on them during operation though). You will get a free replacement for one year and a half-price replacement after that. Sounds like you could use a sabertooth 2x60. However, the sabertooth/kangaroo motion controller combo has yet to be proven as an equivalent to the jrks pid control!

Hmmmm never had any problems until I took it apart. I am also running both motors on a 32amp circuit breaker and that hasn't tripped, so unloaded max draw has been less than 16amps per motor. I will persist with testing the working side and will try adding load to it and monitoring the current.
I have been monitoring heatsink temps and havent seen above 45c.
The winches were free so no biggy if they are not workable.

@bodgy You stated earlier that your motor could draw up to 60 amps right? If it can draw up to 60 amps than it will; it’s just a matter of for how long. Under no load your motor will draw maximum current only for a few milliseconds because it quickly gets up to operating speed. Under load and almost instant reversal conditions however is a different scenario. And while I’m not an expert on circuit breakers, unless it’s like a GFI type breaker, it takes some period of time over it’s trip amperage before it disconnects. You probably haven’t had any problems yet because you haven’t had the condition of needing current over the maximum levels for long enough periods at a time. Good luck with your testing however. But you never know for sure until you can do some real world testing on a rig under actual operational conditions.

I may be able to shed some light here, being the proud owner of 3 fried Jrk's.

Whilst tuning the wiper motor and setting up the Jrk's I had the motors clamped in a vise sitting on a milk crate, limits set and working fine.

Once the motors were installed on the sim rig (2dof seat mover) and powered up things went a little strange, motors jittering and erratic movement, one seemingly behaving the other off the scale. Everything was checked, polarities etc, all good.

Again powering up the same result and there was also interference on the centre screen of my triple monitor set up.

I disconnected the 12volt supply and opened the Jrk configuration utility and noticed that there was erratic communication between the pc and the Jrk until they would no longer connect and no green led on the Jrk.

This is where the mistake was made. On receiving the wiper motors I diligently opened them up and removed the earth wire, or so I thought. These motors came to me gratis from Kenworth, they exhibited some fault and were being thrown out. When I removed the earth I didnt antcipate faulty capacitors on the remaining wires to ground. While the motor was running in the vise and isolated from earth everything was fine, when they were bolted to the frame of the sim rig not so fine.

The first lesson here is that Jrk's do not like an earth path to ground. Fortunately I was honest and emailed Pololu and they sent me a discount coupon for a 50% discount on my replacements, pity I didn't order 3 because I wired one of these wrong way round, motor to input and vice versa and wouldn't you know it, motor took off and smoke and flames came out of the main chip.....bugger.

So order of business would be to check that you don't have a chassis earth, check the motor and input connections, and make sure your motors internal resistance isn't too low that it draws too much current when connected to your power supply.

I have a fair bit of experience wiring brushless motors pulling massive amps, edf jets and rc helicopters and believe me you can get some incredible power and thrust out of a cd rom motor, 250 watts and nearly 1kg of static thrust at 80, 000 rpm, trouble is fun like that only lasts a short time.

Good luck and try your luck with an email to Pololu.