Quark Woes --- Need help please

[wallot]

Looks like i have a same problem. i just made a reciever pack and will see when it happens tomorrow on the track i will disconnect UBEC and connect the pack.

[Dafni]

Had no chance of trying the RX pack today, it was raining all day long.

The Eagletree said the voltage was okay. (3.5V under 110amp spikes) So I think it's not a LVC thing.

It almost feels like thermal cut-outs, but they run fine in another truck with the same voltage/motor and without fans. Temps on the outside of the ESC never went above 60°C.

I hope it was the UBEC, that would be easy.

Thank you for all the input.

Daf

[BrianG]

Wow, this is weird. Just got back from the races and was having similar issues. Except my steering would also momentarily lock up. The steering would come back fairly quick, but the controller took a couple of seconds longer. Temps were perfectly fine on motor, ESC, and lipos. I suspect my BEC or the receiver, but am leaning toward a BEC problem.

[jhautz]

brian, your problem sounds like the BEC for sure. The steering comes back as soon as the bec starts back up and the esc takes a few seconds longer to"reboot" before the power comes back.

[Serum]

what ubec where you using brian?

You are using a mm controller IIRC?

[zeropointbug]

He is using the Quark.

When mine was doing this, after a few minutes of running, the truck would just stop, alot of the time when I would go reverse/forward. But I don't remember if I lost steering or not, but I had to switch off the controller, then on again. It was not thermalling, the case was quite cool. This was actually after I saw the capacitor electrolyte on the outside of the controller (collected dust). So I guess one cap was still working, it was weird.

[Patrick]

My first 2 would cut out a few minutes into a race on 14 cells. (they stop for a few seconds, then go again, usually slamming on the brakes when they stop)
The first one had a lot of smoke coming out of it after doing this.
The second one did it as well, after every run there was a slight burnt electronics smell coming from it which gradually got worse every time I used it. Ater a couple of weeks this controller also only had about 1/2 power on 12 cells, but full power on 14 cells..it would just cut out though.
While I was trying to get this one replaced S&K told me they had been thermalling and I burnt them out, because I kept driving (it's hard to stop driving in the middle of a race though, even if you think somethings not right). I hadn't really considered that much though, because they never got that hot (I was using the heatsink from rc-monster, 1 40mm fan, and sometimes a 3" computer fan). S&K just said the outside temp will be less than the internal temp, which I already knew and it just made me think more about the Quark's poor heat transfer from inside to case.
At first I thought it might be glitching or the UBEC, but it didn't go away when I upgraded from the stock TQ3 (origional e-maxx radio) to a spektrum and except for when the second one was acting funny, all 3 don't seem to do it on 12 cells, so I'm kind of thinking they were thermalling.
I haven't used the 3rd one (got it back from S&K about 1 1/2 weeks ago) on 14 cells in a race yet, because I'm afraid it'll do it again.

This is in an e-maxx with a 7xl.

[BrianG]

Originally Posted by Serum

what ubec where you using brian?

You are using a mm controller IIRC?

Oops, I guess I missed this...

Yeah, ZPB is correct, I was using the Quark. The problem has got to be the BEC though. Remember that ParkBEC I tested? Well, Mike wanted to know how it would do in the Hyper 8. Well, now we know. I had forgotten I put it in there. Seeing as how it is only rated for 1.25A, it makes sense that it overheated under racing loads. I want to do some more testing to see exactly how the BEC reacts when it gets to shutdown temps. Certainly explains my problem!