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

um.. I can't edit the thred title,.. so PICTURE OVERLOAD WARNING

This thread is a full report of my quark thermal mod, and lsp buildup / first runs.

First, here's a list of parts I used to build up my LSP-R

Lightning Stadium Pro-R - HBS66200 - $259.95 - http://tinyurl.com/2vk3c8

HB 22 Degree Front Hub Carriers - HBSC8011-1 - $4.25 - http://www.amainhobbies.com/product_...oducts_id/2692
Hot Bodies Aluminum Front Suspension Holder - HBSC8116-2 - $23.99 - http://www.amainhobbies.com/product_...oducts_id/2760
Hot Bodies Front/Rear Upper Suspension Arm Set - HBSC8005-1 - $5.25 - http://www.amainhobbies.com/product_...oducts_id/2685
Hot Bodies Screw & Ball Front Upper Arms - HBSC8134 - $3.49 - http://www.amainhobbies.com/product_...oducts_id/2886
2x Sportwerks Front/Rear CVD Axles - SWK3177 - $5.99 - http://www.amainhobbies.com/product_...oducts_id/5519
Hot Bodies Front Pins for Upper Suspension - HBSC8012 - $2.25 - http://www.amainhobbies.com/product_...oducts_id/2693
OFNA 2.5x17mm Hex Hub Pins - OFN36055 - $3.49 - http://www.amainhobbies.com/product_...oducts_id/3675
Team Losi F/R Drive Shaft: LST - LOSB3502 - $10.49 - http://www.amainhobbies.com/product_...oducts_id/5925
Team Losi CV Driveshaft Rebuild Set: LST - LOSB3505 - $5.99 - http://www.amainhobbies.com/product_...oducts_id/5928
OFNA 17mm Hard Anodized Wheel Nuts - OFN40550 - $4.25 - http://www.amainhobbies.com/product_...oducts_id/3780
HPI X-Wide Hex Adapter 7.5mm - HPI87534 - $7.75 - http://www.amainhobbies.com/product_...oducts_id/8523

Kyosho 46 tooth nylon spur 1/8 diffs - $5.00 - http://www.rc-monster.com/proddetail...YOIF148&cat=40
Brushless motor mount - Hot Bodies Lightning Stadium - $40 - http://www.rc-monster.com/proddetail...=LSPmotormount
Quark Monster Pro 125B Brushless Sensorless Speed Controller - $280 - http://www.rc-monster.com/proddetail...RK_125A&cat=21
Neu 1512 2.5d/f Sensorless Brushless Motor - $225 - http://www.rc-monster.com/proddetail...2_2.5df&cat=20
Extermal BEC/UBEC - $37 - http://www.rc-monster.com/proddetail.php?prod=6vubec
Hitec HSC-5955 Titanium Gear High Speed Servo - $115 - http://www.rc-monster.com/proddetail...tec5955tgservo

2x Custom built TrueRC 18.5V 5S1P 4000mAh - $90 - http://home.comcast.net/~truerc/custompack.htm
2x Apache Smart Balancer and Guard 505 - $23.95 - http://www.icare-rc.com/chargers.htm
2x Astroflight 109d Lithium Charger - 109D - $119.95 - http://www.astroflight.com/store/sto...nFHIL0syk7G4I7

Other random parts used:
drill bits, and nuts and bolts, various sizes.
1/16" thick 1"x3' aluminum stock, cut into 4 pieces of equal length
2x heavy duty velcro straps
a Pentium 1 Heatsink with a high CFM fan

I'm using a JR XS3 Tx/Rx, and am also currently running Proline Maxx Mulchers on Ofna MT3 (dominator) rims, or any 1/8 buggy rim/tire.

If you'd like me to post a HIGH resolution picture of any posted here, just let me know, as some of the pictures, you can't make out that much detail.
ok, to get started, here's how I mod'd my quark controller.

OPENING THE QUARK 125B WILL VOID WARRANTY, but cooling is improved, and will most likely solve thermal issues, if you have them.

I broke the side of my case off, but if you do the mod, you should try not to ;)
Here's the controller, with the end cap, and cover removed:
http://a4dtm.com/lsp/1.jpg

I found a copper shim that was a little too long, and a little too thin, for a direct replacement, over the stock thermal pads and aluminum shim.
I cut the shim with a dremel to get the right length, and then because it's thinner, I had a friend mill out about 1/2 the thickness of the case, where the capacitors sit.
http://a4dtm.com/lsp/2.jpg
http://a4dtm.com/lsp/3.jpg

I cleaned the components with 91% Isopropyl Alcohol, then used Artic Silver's Arctic Alumina (http://www.arcticsilver.com/arctic_a..._adhesive.htm), I epoxied the shim to the FETs first, and then epoxied the shim/controller to the bottom of the case:
http://a4dtm.com/lsp/4.jpg

The controller's PCB isn't perfectly flat, so using two small clamps kept all of the FETs completely flat against the copper shim.
I also had to file down the little nubs, and the bottom of the motor-wire-side end-cap (if that makes sense). Because the entire assembly now sits a little lower than originally, the nubs don't fit into the slots in the side of the case.
http://a4dtm.com/lsp/5.jpg
http://a4dtm.com/lsp/6.jpg
http://a4dtm.com/lsp/7.jpg
http://a4dtm.com/lsp/8.jpg

Then the copper shim to the case:
http://a4dtm.com/lsp/9.jpg
http://a4dtm.com/lsp/10.jpg
http://a4dtm.com/lsp/11.jpg

This picture shows how much was milled ouf of the case:
http://a4dtm.com/lsp/12.jpg

And then I simply used a bead of the Artic Alumina, to put the side of the case back on.
http://a4dtm.com/lsp/13.jpg

That's all there is to the Quark heat mod.

Now to the truck assembly.
The Losi CVD's replace the stock dogbones in the rear, and all 4 corners get the Sportwerks Axles, allowing 17mm hex's.
The buggy arms along with the pins, screw/ball, and aluminum suspension holder fit in place without any modification.

Mike's motor/diff mount is a direct drop in, and can be used in the motor: right-rear setup like advertised, or if you're running two batteries, it will also mount in a motor: front-left setup (I'm doing the front left)

I found a scrap piece of PCB at work, and used it to connect the center diff mounts, to the steering brace. Any material would work for this, metal, plastic, ect. I used two small plastic spacers on the front of the piece, to keep it ~level.
http://a4dtm.com/lsp/15.jpg
http://a4dtm.com/lsp/14.jpg

I found a good sized heatsink from a Pentium 1 processor, and attached it to the quark with Artic Silver (NON EPOXY), and 2 zip ties.
http://a4dtm.com/lsp/16.jpg

After that, I attached the assembly to the PCB strip, with two more zip ties.
http://a4dtm.com/lsp/17.jpg
http://a4dtm.com/lsp/18.jpg
http://a4dtm.com/lsp/19.jpg
http://a4dtm.com/lsp/22.jpg
http://a4dtm.com/lsp/23.jpg
http://a4dtm.com/lsp/24.jpg
http://a4dtm.com/lsp/25.jpg

so, two zip ties for heatsink to quark, and two zip ties from quark to chassis. the entire assembly sits below the body posts, so I don't need to worry aobut it scraping. and it is VERY secure to the chassis:
http://a4dtm.com/lsp/26.jpg

I put a larger fan on the heatsink, and this is also a good shot of the aluminum suspension holder w/ the buggy arms:
http://a4dtm.com/lsp/31.jpg
http://a4dtm.com/lsp/32.jpg

now I don't have step by step pictures of the next steps, as I did from 8am until 12pm noon today (racing started at noon), I stopped to pick up some nuts and bolts on the way to the track lol, and assembled the battery mounts at the track.

I had to move the steering servo back about an inch, to make room for the larger fan on the heatsink, so that was Drill 4 new holes, and I attached the servo mount with some cap screws instead of countersunk, because I simply didn't have the time.

I took the 4 pieces of aluminum angle stock, and cut them to the length of the chassis. Then drilled 2 holes in each piece (one piece on each side of each battery), and drilled the corrosponding holes in the chassis.. Left to the track, and learned that I had picked up the wrong size scews and nuts, so a fellow racer told me to "have at" his toolbox, and I found some countersunk screws w/ matching nuts. We were racing in a parking lot, so that was ok, but countersunk scews won't work with non-countersunk holes, when I decide to take it offroad.
I loosely put the angle stock pieces on, and layed a velcro strap UNDER them, and then tightened them down all the way. this held the batteries very securely, and was very quick to get the packs in and out of the truck.
Originally, I had planned on epoxying nuts to the bottom of the L stock, so The batteries could lay perfectly flat, and not rest on nuts, but I tried a few times, and the epoxy just didn't want to hold. Welding would be a better solution, but I don't have the skill or access to do that at the moment. To keep the batteries off of the nuts that were holding the L stock down, I plan on using some fairly dense foam, under, and on the sides of the batteries. Today, I was in a hurry, so I settled for two pieces of cardboard under each pack. Worked just fine.

So here's some pictures, then I'll tell you my experience :)

In the first two pictures, you can see the corner of the heatsink poking out of the front window. this doesn't bother me at all, as when it flips (and I flipped and slid about 30feet on it's lid today), the body posts, and rear wing, keep the heatsink off the ground. (also note, clear body on race day = RUSHED lol)
http://a4dtm.com/lsp/37.jpg
http://a4dtm.com/lsp/38.jpg

http://a4dtm.com/lsp/39.jpg
http://a4dtm.com/lsp/40.jpg
http://a4dtm.com/lsp/41.jpg
http://a4dtm.com/lsp/42.jpg


ok, so I benched tested the truck last night, and it all seemed in check. I got to the track today, found the right screws and nuts, and put the L stock pieces on, and made sure the batteries were very secure. then, mounted the steering servo, and went into the LHS to get the right steering link. played around in the parkinglot (off the track) for a few minutes, and set it aside to help marshal. When my first heat came up, I went to the side of the track, turned on my TX, and plugged in the two batteries in parallel into the quark (while the quark was turned off). Immediatly, SPARKS shot out of that small gap where the case had been milled down. and burnt electrical smell filled the air.. I unplugged, and tried again. (I know most of you will say "what?! WHY did you plug it in again!?", but the controller's warranty has already been voided, so it was either already burned up, going to burn up, or run like normal) Luckily, for me, it didn't spark a second time, and when I turned it on, that pretty little jingle assured me that it wasn't completely toast. Applied some throttle, and the wheels spun. I got it out on the track, and the controller never hicupped once. I made it about 3 minutes into the 5min race, when I lost power. Took the truck off the track, and noticed the spur was about 1/2 stripped, and the pinion was just floating. The motor had moved i don't know.. 1/2 of a millimeter. I'm running a 44t diff gear at the moment (Just ordered two 46t gears as replacements) and had 14t pinion on it at the time. The motor mounting holes in the motor mount wouldn't allow the pinion to perfectly mesh with the diff, only about 2/3 on. since the diff's teeth were now about 1/2 height, I had no choice, but to put a 16t pinion on, and try again.. With the harder gearing, I decided I to put a set of 1/8 buggy tires on it, to try and keep the temps in check.
Second race, never got it rolling.. Off the line, veered hard right, and I brought it over to the edge of the track, to discover a missing rolling pin in the right rear CVD. Another quick stop inside the LHS and I had 4wd again, but missed out on the second heat completely.
Third heat. I made it about 3 corners, when I lost steering. The servo horn screw had loosen (how!?), and the horn was just sitting above the servo's output shaft. Tightened that, and put it back on the track w/ about 4 min left in the race. I made it till about 30 seconds left in the race, when I lost a left rear CVD rolling pin.
took it off the track, and had someone temp it, and motor, and controller were both ~135 degrees F.
I did NOT have fans on the motor or controller today, as I didn't have time to solder them up, so I can understand the high Quark temps, sort of, but the Neu was hotter than I'd ever like to run a motor again.. it was about 80-85 degrees today, and humid.. only adding to the problem. BrianG also mentioned that when I sparked the controller, I could have lost multiple FETs, and that could be another reason for the controller running so hot. But I didn't have any thermals. and then again, I never got to run it for more than 5 min at a time..

Overall, I'm EXTREMELY happy with the performance, but it IS running too hot for me, even without fans, I wasn't expecting those temps and after only 3-5 min of hard running.. So, I'm going to get a 1515, and see if that will keep the temps down, and let me run my 16t pinion as a "cool" setup, and go up, if I want more speed out of it.
By the way, I think my biggest problem (aside from the fact that I havn't done any racing of any kind since the first year I was in this hobby, with my STOCK RTR Rustler say about 8 years ago..), was TRACTION. I was in the negative on the traction-o-meter. Down the back straight, was the only place I could keep this thing in some sort of "racing line".
We'll see what happens next weekend. I'll most likely have the same setup, but I'll have time to prep the truck, and get fans on the motor and controller.
oh, and I'd say I put about 20 minutes of runtime in the truck all together today, got home, and re-charged the packs, and they took 1.836Ah. so I'm looking at 40-45 minutes of runtime, just like I had expected.

Here's a short video of my second race. My sister had stopped by, and I asked her to video it.. bad video, and completely sun-washed, but it's something.. I'll probably get more video tommorow night.. My truck's the one w/ buggy tires, and clear body. go easy on my driving style.. I'm a much better basher than racer at this point.
http://a4dtm.com/lsp/race.mov ~10mb

Cool video. Too bad about the problems you were encountering, but glad that you like the truck overall. I have heard its a beast at racing. :027:

Hopefully the next time you race, you will be able to finish the whole race... good luck!!

Was the whole track asphault? Any jumps? Looked like a fun time drifting. :027:

all blacktop.. in the third heat for the MTs, they brought out a wooden ramp and put on the track.. a 1' high ramp at a ~40 degree angle, and a 10' run-up, I launched my truck about 4' high, and it didn't land pretty lol

Whow, sounds crazy man. Why did you mill the section out of the case? Why did you break the side off too? You didn't have to rape the poor Quark. :005:

That really sounds bad that sparks came from the Quark when you first hooked it up... sounds like you shorted something out? I honestly can't think of anything that the Alumina would have done it, that's weird.

Oh, and about the humidity making things worse as far as heat, it would have no affect on it. Humidity is simply a 'feel', just an illusion of being hotter. You can't evaporate your sweet, so you don't cool off. You don't see your electronics sweeting now do you? :032: :005:

Again, that sucks to hear about your Quark almost frying, but it's good that it's still working! :027:

well the humidity annoyed me, and that's enough for me to mention it :)

the shim I have is thinner than the stock aluminum shim + heat pads. if I didn't mill that out, the caps would hit the case, before the FETs.. if I hadn't trimmed the edges of the case, they would have "locked" into the channel's in the case, and the copper shim wouldn't have touched the bottom of the case at all. can tell it's lower in the case, by the feel of the button as well.. pressing the button in to what would normally supress the button, is only touching the button now. I have to press in twice as far as before.

What makes me wonder about the Quark, is I had run it for about a minute at up to say 1/4 throttle on my bench last night.. and ran it for about 5 minutes in the parkinglot, before racing started, and it worked fine.. turned it off, unplugged it. then when I went to plug it in to race, the sparks and smells.. Makes me wonder if it was just a freak accident, that would have happened even if I hadn't done any mods on the controller.. just a component, that finally decided to fail? odd that it happened when I plugged the pack in too.. wasn't an overheating issue..

but, one question I'm extremely confused about..
I ran today, and had no problems as far as batteries.. I've only run these packs in parallel. I usually charge the packs till they peak, then balance them, then run em in parallel.. rinse repeat.
I charged one pack, and it was 42min, and 1.836Ah in.
The second pack just finished, and it took 1 hour, 20min, and 3.336Ah in..

I have no idea why these are soo off.. the only time I havn't run them in parallel, is for programing the controller. I'll try and find a DMM at work tommorow, and check the voltages again. both packs peaked with 21V. if both packs are at 21V, they should both be fully charged correct? any other way to check if everything's in check? charging was at 4amps on both packs.

Where is that track? They actually race monster trucks on asphult? I've never seen that, but it looked like fun. My favorite part was when the turn marshall though you were flamed out.:005: Happens to me all the time too. I normally just blip the throttle and they figure it out. I had one moron that picked it up and then held it by the wheel so I couldnt touch the trottle without risking injury to him. He carried it all the way back to the pits and then set it down and then I took off again. You should have seen his face when I took off. He almost shit his pants.:005:


About the Quark sparks: I'm wondering if with all of the cracks in the case and cutting you did if something like a little aluminum chip or something wasnt loose in there and shorted something out. Could have shorted accross the battery input leads and just disitigrated. My suspision is though that brian is probably right. Its running, but not at its full potential and you may have future problems. I certainly hope thats not the case though.

So what made you want to do that cooling mod? Did you try it and have some sort of heat problem with just using the heatsink. I wouldnt think that racing on asphault would be that hard on the esc. No hills and very little rolling resistance.

Sweet conversion. I love the fact that you got it done in the nick of time.

first thoughts....

1. 135* after a run (even just 4 minutes) isn't that bad under race conditions on a warm day. I've seen my motor temp under 120 after a 30 min race but that was on a cold track. (50-60*?)

2. The packs should take very close to the same charge if they are paralleled the whole time. I would keep them hooked in parallel all the time... only separate them for charging. Don't know why/how they would be off that much... are you sure the charge wasn't interupted and restarted on the one pack or something?

Also... the 1836mah doesn't add up for 20 min of running. It's not right... can't be.

3336mah does sound about right... and even that is very efficient... under 170mah per minute. That's just a bit less than the best I saw when I raced my 8ight at that indoor track a while back.

It's a bit odd seeing Truggies slide around on asphalt like that. I dunno, it just seems a little redneck to me...the whole concept of racing off-road vehicles on flat semi-slick ground.

Good looking conversion though. I hope to get my LSP-R running soon too...if I can only find the time.

That's at HobbyTown USA in Crystal Lake. They don't have a real track, so they do parkinglot racing every sunday.. fun all the same, and even had a jump on the track for the third heat lol.
I cleaned all the parts before assembling the Quark, so there would be .01% chance that a metal shaving caused the spark =\.
I did the mod because I know people have been heating their quarks quite a bit, and since I was running a 1512, and couldn't gear up anymore, AND, I run very hard, I figured I might as well do the mod, while I wait for the motor mount, and assemble the truck. I did the quark mod in my spare time. Just preparing for hot temps.


I'm still confused about the batteries.. I DMM'd the packs at work, and both were 21v. While charging, I had stopped one pack, about half way through, but wrote down the data, and added the two totals. and that was the pack that took 1hour and 20min.. I was monitoring the packs the whole time, and the pack that only charged for ~45min did it's cycle exactly as it should. but didn't put nearly as much back into the pack to peak it at 21v..
I'm gonna try and run the truck again for about 10-15min, and then recharge both packs again, and see what the stats are.


Reffer to my reply to jhautz. Also, HobbyTown USA, may have a new track close by.. (in Huntley for anyone in my area), very large offroad track, that two people have been working on.. there's pictures of the new track, taken last fall, here:
http://www.chitownrc.com/showthread.php?t=5226&page=3 (scroll down 1/2 way)



Also, I ran the truck for about 2min after work today, and had a radio glitch, and hit my works mailbox at about 35mph. completely shattered the rear hub carrier, but no other damage at all.. took a chunk out of the mailbox post too.. that's a felony right? :(
note to self: turn off "race mode" before I run the truck again lol.

Thats funny.... I'm eagerly awaiting the opening of that trak too. I guess I'll see you out there if/when it opens.:027:

The pics don't like me... :(

what do you mean? can you ping http://a4dtm.com ?

They are working now :).

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.
http://img292.imageshack.us/img292/4...ematicshn0.jpg

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:
http://img409.imageshack.us/img409/3...mponentav1.jpg

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.

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 ...

I was going to suggest checking with digikey for a replacement too. It actually looks like it would be pretty easy to replace too. Just don't try to go hacking on it with a radio shack stick iron. You'll want to use a good soldering station with a small chisel tip. If you know someone with a nice Hakko or Metcal or something like that, it won't take long to do.

Of course, all of this is assuming that nothing else cooked.

What are you talking about, that is a CERAMIC capacitor, not a tantalum. Tantulum's are black with lettering on them usually. Who said a short wouldn't kill them?

You should figure out how much work this will be, and if you need to buy anything expensive such a good soldering station and decide whether it's worth it. Or get a hold of S&T to see if they can help?

Replacing this thing will be no easy task, your circuit is permanently attatched to the case...

zero, you're coming off mighty harsh there. We're just trying to help the guy out. As you said, the circuit is permanently attached to the case and he's pretty much screwed. We all know that it's not going to be covered by warranty and who knows what S&T will want to fix it, if at all.

I'm no electronics engineer, but from what I see, it's just a surface mount component and looks to be a $2 part. If he can source it, why shouldn't he try to fix it. I don't think that anyone said anything about buying an expensive soldering station.

Heck, like I said, with the esc being all glued together and everything, he's pretty much screwed. I have a Metcal MX500 station, I'd be willing to give it a try, provided that he can get a replacement part. As I said, I'm no electronics wiz, but I've soldered everything from battery packs to 0603 resistors that my old eyes need a stereo microscope to see.

Why do you think I'm being harsh man?:eek: GriffinRU seems to know his stuff, but I don't know why he called it Tantalum cap.

The cost of the part is almost nothing, probably like 50 cents about?

Do you think you could get the side off the case, as you DID attach it with adhesive right? You might be able to break it. Then the cap should be in plain view. If you have good nerves, then go for it.

I really don't know why they don't have more than just one of these caps there?

It could be just a high frequency filter judging by the size and placement...

soo.... wouldn't that just be a cap then? :032:

Mine is actually sitting high up, like the person who solders them doesn't do it properly.

Zero, I don't know. It just seemed to me that you were coming off kind of harsh. Since I really don't know what I'm talking about with these things, I'd just like to know if the part is replaceable.

A4, can you shoot a pic of a sideview so that I can get a better look at what replacing the part would entail? I mean, if it is an SMT component, I should be able to do what is necessary from one side of the board, shouldn't I? How much clearance is there between the boards?

Well, it probably is just a cap. But it has to have a small value due to the physical size - that's why I said it was for something like low level RF-like filtering. I suppose it could be a resistor or diode, but it doesn't look like it.

As to the solder job, it was either an addendum (therefore soldered by a person), or the traces it attaches to are big enough where the wave solder couldn't grab (acting like a heat sink).

Yah, we figured it was for low RF filtering. The solder job on mine was kinda bad, it was crooked both ways, up and to the side. Personally, i would have designed it so that the little cap was right up there next to the FET's.

AAngel, do you mean between the power board and control board? I think there should be enough for a tip to get in there, and you can see everything fine.

A4, how can you even see down there anyways? Are you sure it is this component that is fried? Seems to me that you wouldn't be able to directly see it? Am I wrong?

If we can determine exactly what it was that fried and it's near the edge of the boards, I do have a 1.5mm 600* chisel tip at a 45* angle that should get in there pretty easily.

I thought that we were talking about that little yellow/orange part that is circled in the pic. Are we talking about something that is between the boards?

IMO, that smoke residue isn't from that cap unless the end of it is blown off or it's cracked in the middle. Zero is right though, it looks like a little ceramic cap to me, probably an 0805 physical size and likely something around 1uF. Anything larger than 1uF in a ~35V or higher rating is probably going to be in a larger physical size package than what's there. However, I've debugged quite a few circuits in the past and very very rarely have I ever seen a failed ceramic cap...maybe once out of a hundred or more circuit cards?

I think the biggest problem here is that the ESC was modified by the user and there is a snowball's chance in hell of S&T covering it under warranty. Taking a stab at what's wrong with the ESC by looking at some residue on the casing isn't going to do that. My suggestion is to at least send it to Mike or someone else with experience repairing ESC's or troubleshooting electronics to at least have a chance it might work again. I don't mean to sound harsh about it, but online troubleshooting of this ESC by pictures ain't gonna work. Case in point, we had a video deserializer card at work this past summer that someone killed when the voltage knob on the PS got bumped and overvoltaged the card. The only component physically damaged was a little voltage regulator, which we replaced. However, even after replacing that regulator, there was still a short circuit on the 3.3V bus on the CCA and absolutely no other physically damaged components on the board. The main point is, a component doesn't always have to be physically damaged in order to have an internal problem.

If you familiar with soldering then replacing this cap is 5 sec deal.
Black usualy goes with panasonic tantalums, EPcos yellow -> and there more brands and styles.
I am sorry but this one doens't look like 0805... check with the rest of the board
and 0805 ceramics caps have different color as well tantalums

Different board great example... thanks to Brian

I'll stick by my assumption it's a ceramic. It's not the yellow color like most tantalums...it's more beige/tan in color. The lighting in your picture and his are completely different and I'm not sure how you can compare them since it's not the same component on the two pictures. And it very well may not be an 0805, but I don't have much size reference in the pic to compare it to anything else. A quick check with some calipers would let him know for sure.

Although, I still say it's BS that the cap caused the smoke mark unless it's cracked or has a busted endcap.

Man...
We talking about caps or smoke? Heck I know where smoke came from, read post above, that the part which was broken...
I am sorry for you that you cannot see my point in comparison...but it is not the color which is counts (you can paintbrush with any) but size and shape which matters. If you that curious then check on web for surface mount components sizes and everything would be clear.
Lots of guys here have the same controller and this cap looks like located in easy to reach and snap picture place.
So bring better picture in studio and I will tell you what it is. From current views I am confident with what I published earlier!

Ceramics do not have reasons to blow, while tantalums are known for that.

Zero, I said "one small change", because I soldered the fan plug before the quark plug, but didn't feel like changing the diagram in MSPaint :)

for everyone:
I don't have any better pictures of the component before it smoked, but here's the one I already posted, at original resolution. I don't see anything on the component at all..
http://img104.imageshack.us/img104/7...0214dh3.th.jpg

and here's some pictures after it fried:
http://a4dtm.com/lsp/3fry.jpg
http://a4dtm.com/lsp/1fry.jpg
http://a4dtm.com/lsp/2fry.jpg

I didn't just assume what part fried.. I took the side of the case off, and looked, and that's when I posted what I think has fried.

I might have to bend the side of the case down a little more, because that is very little room to get a soldering iron in there, and try and hold the component in place.. and add solder,, ect.

We order from digi-key quite frequently at my work, and as for soldering, for the last week, I've been soldering about 4 hours a day.. We've got hakko soldering stations, and multiple tips, including tweezers, which might come in handy. I guess I'll have to contact S&T and see if they'll tell me what that component is, and I'll go ahead and order it, and try and get it replaced..
Do you guys have any other thoughts?

If it IS a cap, I'm puzzled as to why it smoked. Caps are either used to "store" DC or pass AC (depending on frequency). Neither application really lends itself to blowing unless you exceed the working voltage of the cap.

Is it possible that there was a metal shaving laying alongside the device shorting across both solder pads, and when you plugged in the ESC, that shaving acted like a fuse and incinerated? This would create a decent spark and deposit the vaporized remains of the shaving on whatever was close by making it look like the device is blown.

A4, it sounds like you've got it covered.

look at the second picture I posted (http://a4dtm.com/lsp/1fry.jpg). it got hot enough to actually ball up the solder..
There is/was no metal shavings big enough to to short out anything. after the case was cleaned after milling, and after I put the controller in, I blew it out w/ canned air. I tested the controller, and it worked fine. took it to the track, and ran it for a few minutes w/ out any problems. set the truck down.. my heat came up, and i plugged it in, and sparks. I really don't know what could have caused it. other than the second battery making contact on and off. which I'm not sure how often that happened.. the solder joint was broken, and electrical tape was holding the wire to the Deans plug.. being wired in parallel, the voltage wouldn't have jumped up by much, if any. but still possible? i don't know. :025:

Time will tell lol

Well, it was just a thought...

I appreciate it. I really don't know jack, without yours and everyone elses replies, I probably wouldn't be in this hobby. :024:

I am a little bit confused with pictures, is it possible to get a picture which cover full board at once? Quality is great but one piece is always better.

Brian as you mentioned caps can fail under overvoltage and when exposed to currents higher then rated. Rated voltage depends on temperature. Reverse polarity also cause caps failure. Now if you put al this together it can be clear how and when they can fail, especially with poor battery connection.

For tantalum caps reversing polarity is very bad and irreversible ending up with short (90%) or open.

So far looks like tantalums here Ok. By the way what is sparking or where you see sparks?