whatever pictures I have posted are the only ones I have. I didn't take other pictures before I assembled it, and I can not remove the controller from the casing.
Reverse polarity isn't a possibility. and for overvoltage, I'm running 5s on the truck, so don't think so. and it sparked when the controller was switched off, and the truck was just sitting on the ground..

if you look on the first page, there's a picture of the gap in the case, that's a result from my friend milling out a pocket in the case. a few sparks shot out of that opening,. I immediately unplugged the batteries, and smelled the controller, and it smelled like electrical smoke..
so I'm still as clueless as when it first blew.. do you guys think we're getting somewhere? :032:

Well, assuming that you used arctic alumina epoxy, you can get it apart. I've potted small converters in this stuff and had to dig through it to change sense resistors. Really, if you heat it up in a controlled environment, like a toaster oven to about 170*F, the arctic alumina gets gummy and you can actually separate parts and remove the epoxy with an exacto knife.

If you use an oven to do this, be sure to preheat it for about 20 minutes or so before putting in the esc. Ovens tend to spike the heat to quickly attain the desired temp, before settling on the set temp. The hotter you go, the more gummy the epoxy gets. Just don't melt the esc.

Putting it in the freezer works too as it makes the epoxy more brittle. Just a gentle prying action breaks the connection quite easily. Whatever works...

Griffin, I realize that the cap could have had too much current, but wouldn't it have had to be multiple high current charges and discharges? All caps have the inrush of current on initial charge. From the looks of it, that cap is simply on the + and - inputs so it's not like there was an oscillator circuit on it to rapidly charge/discharge. Of course, this assumes that the batteries were connected right - which I'm sure they were otherwise there would be more issues that one cap I would think.

I still think there was something that caused this that isn't directly related to the cap, even though it looks like it suffered for it.

Are we all sure it is in fact a cap and not some sort of avalanche diode to shunt voltage spikes that are too high to ground. It does look like a cap though...

So this is the cap we talking about, right?

As for polarity and overvoltage we covered that earlier in differnt threads, if anyone interested I can explain later in different thread or via PM.

So have we come to agree that this is a ceramic cap? This would take away one explanation, as to reverse polarity, they aren't polarized as you probably know. I did the internal mod to mine, and I am sure that it's ceramic.

None of this makes any sense though, this is a tough one. :032:

In between, if you had one then you should better know which one.
My posts here only based on this pictures:

where capQ is capacitor under Question
capT one of tantalum caps everyone familiar with, not always with markings
and this one I am not sure if you seen this one before.

It is quite easy to identify ceramic cap from tantalum when you have it your hands or close lookup, there are couple exceptions of course, but lets not go there :)

The one under question looks more like?

You don't think those look alike do you?

Tantalum caps almost always come with markings. I don't see why they would use a tantalum cap here, a ceramic is a better choice clearly.

griffin, that's indeed the part that blew. I called S&T earlier today, but got voicemail. I'm going to give them a call on Monday, and see if I can get someone that can tell me exactly what that component is. That should help settle the debate.

I don't have knowledge in this type of stuff as far as what kind of cap it is, or what it's ratings are.. When I need to know the facts, I ask for help haha. So we'll see what S&T says about it on Monday.
I got my body painted finally, and am about to go out to the garage to make a fan bracket for the controller/heatsink.. Then, I think everything will be completely done. I got some 1/4" acrylic, and cut them the same size as the battery, with holes for the screws and nuts to fit in, so they don't poke my batteries. and replaced my rear hub, as well as the 44t diff gear with a new 46 gear. I don't have a camera or video camera, but am still planning on racing tommorow. Last time, everything went fine, for 5min heats.. and this time, I geared up by changing the diff gear, and adding the fans will help. I know you all probably think I'm an idiot for running it w/ out replacing that component, but if it ran fine for 5min heats while it was blown last weekend, I don't see why it will have any problems this weekend, w/ the changes I've made to the truck. I don't like downtime. I'm not going to run for 30min, or run in grass, so I think I'll be ok this weekend. I'll keep you guys informed.

I don't blame you at all for running. I can't stand down time. In fact, I had to send my Compro back to Mike because it wasn't right. I haven't been able to run my Muggy in its proper form in two or three weeks (feels like months). I'm about to scrap the whole thing and just stick with vehicles that will run right on a MM and 4S.

Quote:

You don't think those look alike do you? Tantalum caps almost always come with markings. I don't see why they would use a tantalum cap here, a ceramic is a better choice clearly.

Without close lookup on circuit I cannot tell which component fit better in which place.

There is one more device in simular package cap+fuse.

But, as A4DTM said, we will see on Monday what it is.

I raced today... I ran the buggy tires again, (which are almost worn through in the front) Got there, and w/ in 1min of practice, pinion came loose.. threadlocked it, and tried again. Servo horn came off after about another minute.. Got it going for about 5min, and I threw a rolling pin in the axle stub, and the wheel rolled across the parkinglot..

re-taped the pins in (the buggy rims' hex isn't deep enough, to cover the pin, so I'm using electrical tape to hold them in place).

Then, I set it down, and hoped it wouldn't fall apart while I went to marshal a few races.
My heat came up..
First, under acceleration, I have no steering.. I need to refill the center diff w/ heavier oil, and hopefully that will help, as now, the fronts just spin, and it's not getting enough traction as it could. The track was setup as a sort of tri-oval. one hairpin, one sweeping corner, and two sweeping 90 degree corners.
I got the holeshot EASILY, and I was faster down the back straight than any of the other trucks (for a short while in practice, I was faster than the nitro TC's on the straight :005: )
I made it 2minutes and 19 seconds, and clipped on of the boards on the outside of the sweeping corner.. ~35mph.. I broke the front suspension pin holder, and bent the suspension pin about 45 degrees. The shock cap also got ripped off, and soaked the front end in oil. oh and the sway bar looks like a pretzel. Not too bad of damage.. the CVD was fine, suspension arms were fine. just the pin and the pin holder, which I'll have to order.
After a marshal pulled it off the track, I took the transponder back to the drivers stand, as well as my freq. clip, and when I returned to the truck, there was a small crowd. I heard a couple "that thing is balls out fast", or "that's by far the fastest electric I've ever seen", ect. lol.

Does anyone know what weight oil comes in the LSP-R's shocks? or any idea what weight I should fill them up with?
Also, I'd like some stiffer springs. I haven't found which springs are which.. the truck came with black on the shocks, and a set of red, and a set of blue.. I'm fairly certain the blacks are the stiffest, but not stiff enough for me..
Also, what diff oil should I put in the center? 50, 75, or 100k?

So I had second fastest lap (fastest lap was a full second faster than me.), but I took fastest average lap time.. and finished 4th overall, because I only made it about 1/2 the race. BUT, when I hit the wall, I was in the lead..
Order the small parts, and I'll be back next weekend.. word has it, I might get to take it to a big offroad track on Saturday. That's when I'll need stiffer springs :024:

I'm Nick S

Pos---Car---Name----------Laps------Time---------Fast Lap-----Average Lap-----Leader Gap
1-----1------Nick------------37--------4m49.600-----6.970--------7.827-----------+37 Laps
2-----2------Stunt Steve----28--------4m08.520-----7.300--------8.876-----------9 Laps
3-----3------Kyle S---------23--------4m59.657-----5.438--------13.029----------14 Laps
4-----4------Nick S---------18--------2m19.170-----6.770--------7.732-----------19 Laps
5-----5------Mike Askew----9---------1m12.150-----6.970--------8.017-----------28 Laps

OH, and temps were MUCH cooler. the motor still got pretty hot, but I could keep my finger on it. and the controller/heatsink didn't get much much more than ambient. going from 16/44 to 14/46, and adding the two fans helped a ton.

Here's some pictures (camera's horrible, please excuse the quality):

The Damage:
(note the bald tires.. brand new to bald in about 20min of runtime..)
http://A4DTM.com/lsp/44.jpg
http://A4DTM.com/lsp/47.jpg

This is from the plywood wall I hit..
http://A4DTM.com/lsp/45.jpg
http://A4DTM.com/lsp/46.jpg

countersunk all the battery tray holes:
http://A4DTM.com/lsp/43.jpg

The quality is horrible, but you can kind of see the two fans mounted. the controller's zip tied to the heatsink, and that's laying on the piece of PCB, then the fan is at an angle blowing air through the heatsink from the front..
The motor heatsink is just zip tied around the motor. The red switch that's behind the center diff turns the fans on and off. You can also see the parallel adapter I made. two inputs from the batteries, and two outputs, one for fans, one for the controller.
http://A4DTM.com/lsp/50.jpg
http://A4DTM.com/lsp/51.jpg

Here's the piece of plastic I made to keep the screws from hitting the batteries. Then I put a piece of foam between the plastic and the battery, and they don't move at all once strapped in.
http://A4DTM.com/lsp/52.jpg
http://A4DTM.com/lsp/53.jpg

Hard to see, but my girlfriend has no interest in RC at all, so I made her get involved by drawing a simple picture on the hood. (she's an art student, and draws doodles all day)
It's a person w/ bandages on his arms, and says "look ma' no hands!"
kinda like my driving I suppose..
http://A4DTM.com/lsp/48.jpg
http://A4DTM.com/lsp/49.jpg

anyone? what center diff oil should i use? and what weight shock oil?

edit-
I just got off the phone w/ S&T.. They told me that they couldn't tell me what the part is, and wouldn't ship me the component for me to switch out myself..
To have it sent in, to get looked at, it'd be $25 minimum to have it tested, and then $7 or so for shipping. and then whatever they would charge to replace anything that's damaged. They also said if I wanted a new controller, I would get 1/2 off, if I sent the controller to them..
SO.. I suppose I'll just run it until someone figures out what the component is.. and replace it.. for now, I'll just run it like always.. if it goes up in smoke, I'll send it in, and think about getting a new one at 1/2 price.. but 1/2 price is still $140.. and no one knows how much the tekin or castle controllers will cost, but will most likely be better controllers..
I asked if he could tell me the part number of the component, just out of curiosity, and he said he didn't have the technical details of the controller... lies.. :019:

well w/ no clue on what to order.. I went ahead and ordered this stuff:

AMAIN:
GS Racing Pure Silicone Shock Oil 50 Wt
Mugen Silicone Diff Oil 50,000wt
RMV PBR Extra Hard Progressive Rate Truggy Spring Set (LSP, ST-R)
Hot Bodies Front/Rear Lower Suspension Pins (4), (Lightning Series)
Racers Edge Kyosho MP7.5/MP777 Front Hinge Pin Brace

TOWER:
Ofna MT3 Splits White Wheel (4)

MIKE:
Neu 1515 2.5d/F Sensorless Brushless Motor

my 1512 2.5d smooth can is for sale now btw..

I think you should be good with 50K wt. center diff oil. My buggy is running 30k, and the front tires get pretty damn big. My Revo has a 1/8 scale center diff in the center (slipperential-style) with 100k oil, and the front tires still balloon (but it will still wheelie pretty well).

In my revo I'm now running a full truggy drive line with 1/8 diffs front/rear and center. So far I've tried 10K rear 25K front and 35K center and I thought it was too light. Last time out I ran 10K rear, 35K front and 60K center and I thought I was about right. It pulled out of the turn really well without totally unloading the inside wheel.

I tend to like a little heavier diff fluid than most though.


Is the off-road track you mentioned the new one out in Huntly. I've been waiting to hear when that was going to open. If you hear any news on it shoot me a PM I can t wait to get out there. Finally a track that less than an hour away! Woo! Hooooo!!!:dft003:

you both got PMs.

jhautz, I'm expecting a call from a guy named Mike that I met at Crystal Lake's Hobbytown USA. Him and a few other guys are trying to setup a track test day of sorts out in Huntley. I'll shoot you a PM as soon as I get word. I'm not sure if my truck will be running by then, but I may stop out, if you can make it.

Sorry for the newb question... but what exactly is the difference between the Neu 1515 2.5d/F and the 1512 2.5d smooth can? Does one have a heatsink built in? I thought I heard this somewhere, but to be sure... does the "f" in 2.5d/F stand for fins? Meaning it has a built in heatsink?

Thanks. I am still learning about all these different types of motors/ESC's.

yes, the F stands for finned.

the 1515 is longer than the 1512, and will have more torque, but less kv(rpm) than the 1512.
I'm going with the 1515, because I want the extra torque to turn MT tires. I've been running the buggy tires so I don't heat up the 1512 too much.

I run 50,000 in the center dif on my mbx5 & the tires dont swell at all.

I installed my new hinge pin, and kyosho 777 front suspension arm brace/holder, got 50k weight in the center diff. I need to rebuild the two front shocks, and put on the stiffer springs all around.
but my big news, is it's now got a 1515 2.5d/f :).
I'm waiting for the MT3 rims, and I'm going to mount the stock tires on them, with fiberglass tape, and a few tubes of shoogoo. I'll shoot some video tommorow or Sunday.
happy weekend guys.

Good for you. My 2.5d should be here Wednesday, along with my Quark.

I ordered my 1515 2.5d a few days ago and should be recieving it in 4 or 5 days.
I also want to use it on 5s with a Quark and in a 1/8th truggy (Thunder Tiger ST-1 Pro), so I'm interested to know how it works for you, and maybe learn from your mistakes ;) if there are any.
It will probably be a few weeks though before mine is finished.

Patrick, I am looking forward to getting the new setup. I'm running a Losi Muggy and it is quite a bit heavier than most truggies, so everything I've tried so far, hasn't performed to my expectations. I've gone through a few Mamba Max controllers and I recently got a Compro. The Compro may or may not be working properly. All I can say is I don't like the Compro. I'm hoping that the Quark will do what I need it to.

I'm sure that I'll post something once I get it wired up.

it works good.
I ran 14/46 gearing, and it wasn't as fast as with the 1512 2.5d, but it had a little more torque, but it's hard to judge, because I also used the 50k center diff fluid w/ the 1515, so it wheelies fairly easily now.
but, temps were VERY good. the batteries got warm, not much over ambient though, the motor was just a little warmer, and the quark/heatsink were only as warm as the batteries. it was only a 7 minute run, but when I used the 1512, the motor and controller would got this warm idleing lol (not really, but it got very hot, very quickly).

finally the motor moved a little, and stripped the diff gear. 3rd time this has happened.. more threadlock on the motor screws?

speeds are I'm only guessing, but 35ish? going up on pinion a bit will get my speed back :)
I'll post a video later tonight.

Are you using loctite on the screws going into the motor? I don't think that's a good idea. I may be wrong, but I'd hate to risk any of that stuff seeping down into the bearings.

I don't remember if you mentioned it, but what battery config are you running? I'm running an 8XL, which has a KV rating similar to that of the 2.5d, on 5S and it is nuts. I'm talking uncontrollable at full throttle, geared 12/46 with MT tires. I'm almost thinking that I should go with an even higher turn motor, maybe a 1500kv.

looks like 4s TrueRc 8000mah from the photos.

2x 5s1p 4000mah packs in parallel.

Those should do nicely. It should be borderline stupid fast.

oh, and I didn't loctite the motor screws yet.. dunno what else to do to keep the motor in place though.

my video from today:
http://youtube.com/watch?v=ldDo9bDGTlk

Here's how I strapped the tires to prevent ballooning.. not tested yet, but I'll find out how it works later today.

you need:
tires, foams, and rims
roll of fiberglass tape
big tube of shoe-goo
piece of scrap plastic

wash the tires in warm soapy water first, flip the tires inside out, then wrap a piece of fiberglass tape around the tire. I wrapped the tires twice around.
http://a4dtm.com/lsp/tires/2.jpg
http://a4dtm.com/lsp/tires/3.jpg

Run a very heavy bead of shoe-goo around the tire. the more goo the better. (I ended up making the bead about 3x as what's in the picture)
http://a4dtm.com/lsp/tires/4.jpg

Use a scrap piece of plastic to spread the shoe-goo, and push it into the tape's square holes.
http://a4dtm.com/lsp/tires/5.jpg
http://a4dtm.com/lsp/tires/6.jpg

After the goo's dried, flip the tires right side out, put the foam back in, and glue em to your rims.
http://a4dtm.com/lsp/tires/7.jpg
http://a4dtm.com/lsp/tires/1.jpg

the end. I'll let you guys know how it works when I get done racing.

ok, help. I didn't race today, as my batts were dead..

the pack's voltages are 14.89v, and 14.40v
they're both below the 3v/cell cutoff I had set on the quark, but the quark never shut down.. I just could tell I had no power, so figured they were low..

now, when I hook them up to my astroflight 109's, it detects them as 4s packs. should I just let them charge a bit, then disconnect and retry, and see if it detects them as 5s packs?

*edit
nevermind, after about 3 minutes, the voltage is around 17.5v, and the charger's readout changed to reflect a 5s pack. but.. how good is the quark's lvc, if it kept letting me run, when both packs were below 15v?

Yep, that's the only way to revive packs using the AF109.

Are you sure you set the LVC on the Quark right?

Also, if you hook up a pack that has some runtime already on it, it could fool the ESC into thinking it is a lower pack. For instance, a 5s pack at 3.36v/cell could fool the ESC into thinking there was a fully charged 4s pack attached. Both would be 16.8v.

ok, thanks. That makes sense Brian.. I wish I could manually set the cell count on the quark.. They're charging up fine now though, and then I'll take it out and try my new tires. Problem is trying to find a big patch of dirt to see what it does in the rough stuff =\

NICE tire-job A4DTM!! :018:

Looks like someone took my advice? That's exactly what I was thinking when I made the thread on the subject. Just a thought, maybe it would work even better if apply the shoe-goo first, then the fiberglass on that?

Let me know how well they work like that! :027:

word. I've got about 10 min left till my second pack peaks, then me and my cousin are going to try and find a pile of dirt or something. I'll get video for sure.
I thought about putting the shoe-goo on first, but it gets "tacky" rather quickly.. I found if I put a large amount on say 1/3 of the tire, and press it into the tape, it fills all the holes completely, just fine. I don't think I'll have any problems. If I did a bead around the entire tire, by the time I would go to press it into the tape, it was tacky, and would start to collect on the piece of plastic I was using, or just take the shoe-goo out of the holes..

Yeah, at anything over 3s, the controller has to make some assumptions about cells count - like that most people install fairly fresh battery packs that have a voltage of at least 4-4.2v/cell. I too wish you could set cell count to get rid of that possibility for error.

Also, Quark's LVC table goes as low as 2.2v/cell, but only as high as 3v. I don't know of anyone that runs that low! I suppose that cutoff would be good for A123 cells, but I'm sure the Quark is calculating cell count based on normal lipo cells, so that wouldn't really work either. I'd like to see cutoffs from no lower than 2.7v, but as high as 3.3v - much better range IMO.

Nice job on the tires too. I'm interested to see how they work as well, especially long-term.

Brian: Do you think my problems before could have been in part due to the LVC in the Quark? I did have it to NiMh High setting though. But a couple of times, when I reprogrammed, it would not save the settings. It's really frustrating.