HOW TO: Quark Mod / LSP Conversion *PIC OVERLOAD WARNING*

bump.

first, AAngel pm'd me asking the weight. truck weighs 7.5lbs RTR on a bathroom scale, with buggy tires on it.. give or take 3lbs because bathroom scales aren't very accurate for weighing light stuff =\. not sure how much more w/ MT tires. 1lb? sorry for the delayed reply AAngel.

second. I figured out the problem with the batteries.. while taking my parallel adapter apart today at work, I found one of the battery wires ripped off of the Deans plug. I'm not sure how it didn't short, and not sure how it broke off.. the solder tab on the plug was bent down at a 45 degree angle, so it hit something very hard.. with electrical tape holding it in place, I'm guessing it was making contact only intermittently. I'm have no idea when it happened, but The packs had different charges after my day of racing.. and then I had run it again at work for a minute or two, and checked w/ the DMM, and sure enough, one pack was 20.5v, while the other was 20.7v.
That's all fixed now, and I also added in another plug and a SPST switch for two 12v fans, that will be running at ~9-10v each. One for the motor, and one for the controller. Here's a simple diagram of my wiring setup:
(once small change. I attached the Deans connector for the fans BEFORE the Quark's Deans plug, that way, I can unplug the controller, and still run the fans to cool the controller/motor, if needed.


and last, I opened up the Quark to see what I had blown. I can't take the controller out of the case, but on the bottom of the lower PCB, between the battery positive lead and the rows of FETs, there's a small component that blew. The case is black w/ smoke directly below it.. Here, look at this picture:


I'm wondering if that could have fried from the one battery making contact on and off.. sudden extra burst of power? the packs aren't in series though, so I'm not sure.. more importantly, how important is this component? I could try and cut a hole in the bottom of the case, and replace the component myself, but metal shavings would be EVERYWHERE, and don't think I'd want to risk it.. depending on how important it is of course..
the component did NOT short out, and is completely unrelated to the shim/epoxy/case modification.
I've got pictures of it fried if needed, but they're on my girlfriend's camera, and she doesn't have computer access ATM.

Also, w/ only one battery being run in this truck, I'm suprised that the packs haven't given me any problems, because they're only rated for 40A constant, per pack. I need to run it for a while ~30min, and see how much of the packs have drained, as I have NO idea how many amps my setup pulls..

ALSO, what's your opinion on this.. I don't have any extra money right now, and seeing as the Neu 1515s are $280, how do you think a Feigao 9 or 10XL would work for the time being? I know they're not as efficient, or powerful as the Neus, but I'd just like to keep the temperatures down, and I can't gear my 1512 up anymore than 14/46.

I'm hoping the fans, and going to the 46t diff will help a little this weekend, we'll see.
I might be bashing tommorow, and racing for sure on Sunday.. my buggy tires are completely bald, and just don't have enough grip on pavement, where we run.. and I'm afraid of using MT tires, because of the heat..
wish me luck.

[zeropointbug]

K, that thing you are pointing at is a small capacitor, ceramic surface mount type. They are probably meant to absorb high frequency EMI in the power stage. I don't think they are absolutely critical to operation, but i'm sure it takes a load off the other caps, and the FET's maybe. (high frequency is hard on components)

Don't even try replace it though. Are you sure it didn't short out on the Quark case? Unless it's a dud, which is very very rare for these types of components, these caps are made by the billions each year.

Oh, and that pick, you CAN'T unplug the controller without unplugging your fans...

[GriffinRU]

Originally Posted by zeropointbug

K, that thing you are pointing at is a small capacitor, ceramic surface mount type. They are probably meant to absorb high frequency EMI in the power stage. I don't think they are absolutely critical to operation, but i'm sure it takes a load off the other caps, and the FET's maybe. (high frequency is hard on components)

Don't even try replace it though. Are you sure it didn't short out on the Quark case? Unless it's a dud, which is very very rare for these types of components, these caps are made by the billions each year.

Oh, and that pick, you CAN'T unplug the controller without unplugging your fans...

LOOKS LIKE TANTALUM CAP and they do fail very frequently with fatal shorts.
This cap need to be replaced with proper one otherwise you will stress other components.

Based on Quark's operational voltage and caps size I will guess 1uF to 4.7uF value with 35V. Check www.digikey.com for good LOW ESR Tantalum replacement. If You have better picture then you shoud be able to read something like 4u7 or 3u3 ...