Well, the inrush current spark would be an issue if the current had to go through the ESC circuit to get from the battery to the cap, but since the caps are usually close to the battery input, that wouldn't be the case.

A cap can supply a LOT of energy and discharge very high currents, but an ESC is a high current device specifically capable of high currents.

The voltage on a cap can only be as high as the battery supplying it. It's not like a coil where you can have a reverse polarity inductive kickback many times higher than the input voltage.

Perhaps a display of ignorance, but is there a single cap solution for what we are doing here? I have six of the 35v, 330uf, low esr caps in a bank. Could I have just used one big cap? That would allow us to take advantage of the rather long leads on the cap to directly solder them to the pcb where the power leads are. I haven't seen any significant benefits to running the caps on the Quark, except that I haven't blown it up yet. The MM seemed to show great benefits, but the Quark hasn't. I'm wondering if that 1" or so of wire that I have connecting the caps is too much resistance or too long of a distance.

I think the main reason for lots of smaller caps vs one big one was that lots of smaller caps have a greater surface area to dissipate heat, and a lower internal resistance rating too- regardless of both sizes being low esr models.
It cant hurt to try one long cap though, the type with a leg coming out of each end, so you can mount it like you said. Would look much neater anyway.

The leads on many caps can carry more current than the leads of a single cap. Also, more caps have a better transient response.

The cap was susposed to even out and remove spikes and other types of noise that the caused the ESC to heat up. It has been 6 months since I read the stuff but check out Tekins forum they talked about this information on a couple of G-10 and G-11 forums. This may not be relevant due the the ESCs being different animals with the frequency of the brushed ESCs and using the regenerative properties. I am looking at getting into the Truggy brushless and guessing on what to order. I am not an expert but just wanted to relay information that could potentially help.

plumslow, thanks for the info. The more the better.

As for your getting into a brushless truggy, I really can't speak highly enough of the performance of the Mamba Max on 4S lipo with a two pole motor. The Feigaos run really well, but suffer from excessive heat; but what do you want from a system that goes for less than $200. If you have the money, the MM and a Lehner 1940 8 or 9 hi amp would be a killer setup. If you want to go with a four pole motor, the Neu/Quark combo seems to be the hot item among most here.

Due to personal experiences, I'd recommend the MM/Lehner combo.

AAngel, haven't we gone over the whole cap thing before? :005:

What a couple ppl said about too large a cap, I can't see it, maybe they just meant for plugging in sparks? The more caps/larger you use, the better.

AAngel, also I find that weird that the MM would see such a benefit for you, and not the Quark. The MM already has more 'capacitor' (3x 330uF) than the Quark, CC doesn't even recommend them for these large R/C's, S&T DOES recommend them, and from your experience the Quark doesn't really benefit from them temp wise. But maybe temp is only part of it then? Adding more caps to the Quark will definitely save the stock caps from blowing, but we don't know yet if it makes for more efficient switching with it.

I will have to see.

BTW, I just ordered a DX 2.0 for my maxx, so it will most likely be night and day for me as far as radios go...

I looked at the MM caps. Although they are 330uf, I belive that they are only rated to 25v. That may have made a difference. I wonder what would happen if you replaced the stock caps with the 35v version.

I run Spektrum in all of my vehicles. I have three of them...A DX3, DX2 and DX2.0. They do work well for me.

Yes, but that is still more than what you use (4s Lipo typically), and having three will have a lower ESR impedance than having 2 of higher voltage.

I did a test of these caps, I reverse polarity, slowly increase voltage until I got to ~16v, then they quickly inflated and blew out.... stinky, don't try at home. :020:

I'm sure the Spektrum will work great for me, especially coming from the TQ-3.

Love my Spektrum too!

I received my Quark back yesterday, my Spektrum dx2.0 today, S&T also sent the PRO-BEC (very nice). The PRO-BEC is made by S&T and looks to be very well made, and is very small, about 1/3 the UBEC.

I attached the Quark naked board to a decent sized heatsink with the stock thermal sticky pads, and then shrink wrapped it, as well as adding two extra caps on the input bar, opposite of the stock caps. (this is temporary)

Even with a large heasink on there, and moderate driving the Quark got very hot. The heatsink got very hot and just almost as hot as the output wires, but no thermals, and the caps stayed only slightly warm to touch.

http://picasaweb.google.com/SethHuls...49267617195762
http://picasaweb.google.com/SethHuls...49267617195746
http://picasaweb.google.com/SethHuls...49271912163074
http://picasaweb.google.com/SethHuls...49271912163090

AAngel: With my Spektrum radio now, I don't have the low speed capability I had with the stock TQ-3 radio, it's definitely not a snails crawl anymore, which I miss... but no more glitching!

Seth; have you got more pics of that BEC?

surprising that the controller still gets that hot. Good thing the thermal shutdowns are history.

There you go. :)

http://picasaweb.google.com/SethHuls...60047985108770

http://picasaweb.google.com/SethHuls...60047985108786

And yes, this Quark surely dissipates mucho heat! One high speed run and it's warmed up good. I am paranoid now over the Quark after the big ordeal.

I've been running what I call my Frankenquark for a while now. It originally had a bunch of heat sinks on it but I found they were not necessary. http://www.rc-monster.com/forum/atta...1&d=1159475519 It always ran very cool but the caps would always get very hot as high as 200 f. Well after blowing a few caps I decided to try the sky extra cap idea. So far so good. The piece of angle gets 105 f directly over the fets and were the two pieces of angle overlap and bolt to the chassis they got up to 145 f. I thought that was a little odd. I thought the angle directly over the fets would be the hottest area? The wires and the area were the caps are soldered to the wires also got up to 145 f. This is without a fan in a crt geared 15/46 with big tires driven very hard for three straight sets of orion 4800 4s lipo packs (about 40-45 minutes of continuous racing).

Looks good ZPB. How hot is hot? Did you temp it?

One thing though, it looks like the shrink is all the way around the heatsink. You might want to allow some better air flow over the heat sink fins so it can get rid of the heat.

zpb, my Quark still gets hot too. Much hotter than my MM esc. That's why I was thinking that the caps weren't helping, but since I added the caps, I haven't blown anything and the cooling mod did stop the thermals.

I might go the my LHS and pick up a "better" radio. Didn't someone else just release a nice radio?

I need to get the new radio because MGM says that there wasn't anything wrong with my Compro. They are blaming my problems on the Spektrum, so I'll have to see.

Thats wierd. I just set up my MGM 160-24 with spektrum and didnt have any problems.

I did have a probem with mine onlyu beeping when I plugged it in, but I figured out that the 160-24 doesnt have a BEC built in an when you unplug the red middle red wire it just doesnt work. Once I plugged in the center wire, it was all good.

Yeah, I am going to cut a larger hole on the other side of the heatsink, there is only a small hole there now. I am sure that has something to do with it, and the fact that the stock thermal pads plain suck... I need to get that heatspreader clamp from my machinist, waiting.... :025:

But yes, no blow ups yet!

SMHertz dog, do both the top and bottom FET's on your heatsink get to the same temp? Maybe it's not touching some of the FETs?

AAngel, I have been playing around with the radio last night and with all the EPA and stuff, and got almost all low speed capability back now, but still not what it was, there isn't near as much travel in the spektrum, I like more travel. (throttle trigger)

Now if there was only a way to test high voltage before I get the Neu 3D.

Yes.

I used artic ceramique on the fets/angle on both boards/angles, but I used heat tape between the chassis and the angle maybe thats were the bottle neck is?
The chassis measured from under the truggy in the area were the angle is bolted measures 125 f.

ZPB, one idea to get more throttle travel, or at least more perceived sensitivity, is to have a longer trigger- how you might do this mod is another thing though. And I noticed your A123 packs dont have balancing taps (may be going blind though), does it make any difference, or is it just not really required with the Li-ion cells?

jhautz, I tried both of my Spektrum radios and the MGM wouldn't program for freewheel.

I was surprised when MGM said that there was nothing wrong with my Compro. The radio is the only thing that I have to look to now. When I get the Compro back, I'll just have to try it again. If it doesn't work, I'll just dump it. Maybe I'll just send it to you to see if you can get it working. LOL

I'm just kind of hesitant to have you confirm that I am, indeed, an idiot.

That is truelly bizarre. Have you thought about trying that adaptor thing which is used to operate a plane/heli esc via pistol grip radio? Pixstick or something it was called... Also, have a good fiddle with the epa setting etc (I'll refrain from making a joke about playing with your knobs.... ah, too late).

Hey, I LIKE playing with my knobs.

Anyway, I did try turning the throttle epa up to 125%. Perhaps I should try turning it down. I don't know. All I do know is that I've been waiting for around a couple of months just to have MGM send me back what I sent them in the first place.

I had the same problem with my mgm it was like the drag brake was always on. I never figured out anything that fixed it.

Whenever I program a radio to a new ESC, I always make sure EPAs are set to 100% (no more, no less) on both the forward and reverse directions (they are seperate settings on a Spektrum). Also, set the trim to centered.

Brian, that's the same thing that I do. With the MGM, I went as far as to reset my Tx to factory default settings on everything, to make sure that I didn't miss anything. Still no go.

Do you know if MGM actually tried to run it in a vehicle, or did they simply use some type of diagnostic equipment?

I don't know about this, I managed a run in today, boy this 7XL is a handful. I forgot how powerful it is, I am wondering if the 1512/2Y would have been a better bet than that 3D? Mike said it's in Wednesday, but it's not too late just to use a different motor as he said.

I now want 7XL power or LESS, not MORE! No matter the terrain, I can wheelie at any speed! It's just too much.

My Quark thermaled today too. :mad:1 :019:

lol, just stay out of the throttle as much and it'll be controllable. :) That kind of power is addicting though. I'd rather have it and just turn it down than to want it but not have it.

Brian, I don't know what MGM did. All they said was that there wasn't anything wrong with the controller. That was a couple of weeks ago. I still haven't gotten it back. I suppose I could shoot them an email and see.

ZPB, the 1512 should pull less current than the 7XL, so don't freak out about the thermalling yet. Wait until you get the Neu in and see what happens. I think that the 3D will be a very good motor. If it does turn out to be too much, then pull a cell off of the pack. You will also be able to gear down a bit too. The Neus are supposed to be able to handle that without over heating.

Yeah my Quark seems to be running cooler with my 1515 2.5d compared to my 7xl so far, but the weathers not as hot here any more and I haven't gotten to use it properly at racing yet, but I still think it would be hotter with the 7xl.

Just because I have an itchy trigger, and my finger just HAPPENS to be 'happy'.... :005:

That's true, I am getting better at the throttle part of things. But now when relatives or friends want to drive it, I can say 'yes', with the EPA on my radio... turn it to 35% and they are good, then watch you at 100%. :027:

My 7XL, with my eagletree, I am recording CONSISTANTLY over 130 amps, so yes I expecting the 1512 should be below 100 amp spikes. I just can't believe the amount of heat the Quark is able (why?!) to dissipate!

JHautz, have you tested out 6s lipo with the cap mod Quark yet?

Aangel; the problem with the MGM dragbrake happened with my 24160 too, i thought i was crazy and had a programming screwed up. Read the manual, i found it rather confusing to read the description, there are some contradictions in it.. like if you don't want dragbrake you don't put the option to off. something like that

I think thats were the newer models will be better, with the same programming ease of the MM- they have that new pc interface software.
Ah, the joys of the HvMaxx, no programming problems, because there are no programming options as such!

Serum, I tried every possible combination that I could think of. Drag brake on/off with the freewheel on/off. I could not get the Compro to freewheel.

According to MGM, they tested my Compro "extensively" and they couldn't find anything wrong with it. It looks like I'm going to be eating this one. I didn't even get the opportunity to blow it up the right way, by playing with it.

BTW, did you get your caps? I sent them a long while ago.

ZPB, my quark gets hot too. I've given up on taking temps. I've gotten to a point where the case is reading around 135F, but the area around the motor leads are always 165F or so. I haven't had any thermals, but on the other hand, I've been afraid to run the Quark really hard.

When I was having trouble with the prior units, Frank was always sure to point out that the feigao motors are really inefficient, as though he was inferring that the motor had something to do with the esc going up in smoke. I'm waiting for my Neu to get back (it's been two weeks today since I sent it off) before I really give it a workout.

To be honest, if the Lehners become available again, I'll grab me a couple of 1940s and then my Quark, Neu, and Compro are going up for sale.

I've had it with all of his crap. At least the MMs do way more than they are supposed to and I've heard very few complaints about the Lehners. I'm just having a hard time deciding between the non hi amp and the hi amp versions.

Did you try increasing your neutral range? It seamed to help mine a little but it didnt solve the problem just masked it.

Yes, I did do that, but all that does is make the neutral range easier to hit. It doesn't make the freewheeling work. Besides, it still leaves the possibility of not letting off of the throttle enough to hit the neutal range.

It shouldn't be this way with a $200+ esc.

What can I say, I'm just bitter. LOL

I dont blame you, I wreck enough on my own I dont need any help from my brake happy ESC. :031:
They must have had brake issues during R&D and released it anyway.

Seems like the more expensive the controller the more problems they have, eh AAngel... :005:

zpb, it sure seems that way. There is still more stuff to try though. Castle is taking its time with the MMM, but I think that it will be good when it does come out and the Tekin controllers should be interesting.

There has also been talk concerning the Kontronik motors and Mega is releasing motors for rc cars too. The future is either looking brighter or the money pitt is about to get larger.