Quark fried, blown capacitor...

Suicideneil, it is red. We run on red dirt. That stuff is a PITA. It gets everywhere. I actually have clothes that are relegated to "track" duty, because this red dirt stains if it gets rubbed in.

Yes, I'm in the states.

[zeropointbug]

AAngel, let us know how your MM does with higher gearing, to entice some cogging to happen. I'm really happy that the caps worked so well, especially with a MM.

OK guys. Since the Quark had to go back to S&T, I decided to get rolling with the MM, so I cleaned everything up a bit. The 8ight is running so well, that I may just get rid of the Quark and the Compro when I get them back.

Anyway, here's the latest version of my cap bank. Again, it is a set of four caps, encased in aluminum and epoxy mixed with aluminum oxide powder.









I kept the fan on the esc for super cool running. The problem I'm having now is that I used to use the temps to adjust gearing. Now the esc runs so much cooler than the motor, I find myself overgearing and I can only tell because it starts to cog.

Right now, I'm running 14/44 gearing with a 9XL and the MM on 4S lipo. Does that gearing sound right? Do I need to go up or down on the pinion/spur?

zpb, I have it geared at 14/44 because it just starts to cog sometimes when I take off. Not bad, but just a bit. I DON'T like cogging, so I left it at 14/44. I don't know if I'm comparing apples to oranges, but I was running 14/46 in my buggy with the 8XL. I figure that if I went to the 9XL in the buggy, I'd go to 16/46. Now if you can follow my logic, I figured that I'd need to gear down a bit to compensate for the larger tires on the truck, so I'm back to 14/46 with the 9XL for being a good gearing in the truck. Since I'm running a 44T spur, I'm acutally a bit higher than I wanted. Sorry for the logic process, but I suck at math. Motor is still getting hot. About 160 after 5 minutes of "I'm trying to kill it" running.

The esc is running 120. What I know about the behavior of brushless systems, I should need to gear up a bit to run the esc harder and cool the motor off a bit, but I can't gear up any more. Or don't want to. Maybe I'll wind up keeping the Quark after all, but then I'll have to muck with the beautiful setup I have now.

[gixxer]

glad to see that you like your 8ight-t, mine is still waiting for a motor mount. also looks like the extra caps are helping out a lot. I wish my mm ran at 120. as for gearing I run a 16/46 with the 9xl in the buggy.

[zeropointbug]

I am so glad that the caps are working so well AAngel.

That's the thing now, you could gear up some, but the MM will cog like you said too high gearing.

You HAVE to tell me exactly what you did for the cap bank in alum oxide/epoxy.

I am thinking of putting two 5.5mm plugs on my custom Quark case, just so they are there for anything, like an ultra-cap bank, or whatever...

zeropointbug, I'm going to try to get someone to run by the post office for me. I'm going to be in trial all week and won't be ablet to. I'm borrowing a computer right now to clown around while I'm waiting.

As for the plug thing, I too was thinking about that. Just makes things more versatile. The only problem is that the plugs degrade over time. I know that I change mine often on my escs and motors. I don't like the idea of having to bend them to make them tight either.

I hope that my Quark gets here in the next week, if they fix it. The way my luck has been going, they might tell me that it's not covered for whatever reason. But...if I do get it back, I think I'm going to make a bank that will fit as many caps as I can within a length equal to that of the Quark. Then I can just epoxy the Quark to the cap bank and then epoxy that to the heatsink.

The epoxy is easy. The aluminum oxide powder can be found at hobby shops catering to rock collectors. They use the stuff to tumble polish rocks (go figure). Get the finest powder that you can. It costs around $8 for a 1lb bottle. I just mix up my two part epoxy and then add the powder until the epoxy turns into a paste that looks like thermal epoxy. They you just apply it as you would the epoxy. Once the epoxy starts to heat up, it flows really well and gets into all of the nooks and crannies. I won't say that it works as well as Arctic Alumina, but it does work well. It does move heat.

gixxer, 16/46 in a buggy? Man, I started running 16/44 with the crimefighter mtrs this morning. After a HARD 5 minute run, I was reading 150 on the motor and 125 on the esc. I'm finally loading it enough to get the esc to generate a bit of heat and cooling the motor down some. What's wild is that the caps on the MM used to get hot. After a run, they were always hotter than the heatsink. Now, the caps are way cooler than the heatsink. If I get a wild hair, I might try popping the sink off of a MM and putting a better sink on it.

I do have to say that all of this leads me to some wondering. Actually, I'm starting to think that I'm full of it and all of my positive results have been figments of my imagination. I mean...if adding caps is all it takes to make things run so much better, why aren't the manufacturers doing it? I'd gladly go for an esc that runs cooler at the sacrifice of some space. Of course, I suppose I just have to keep in mind that we are running these escs out of spec; but hey, my MM got hot when I ran it in my T4 too.

[/QUOTE]I might try popping the sink off of a MM and putting a better sink on it.
[/QUOTE]

You could use a larger fan instead. This one that I use is a 30mm fan. Here is a pic. It hangs over a little but It covers more area and blows more air. It is held in place with 2 screws (the zip tie is holding the ESC in place).

[zeropointbug]

Have you mounted up some extra caps to your MM yet?

Cartwheels, did you get those capacitors from AAngel? Or did you buy your own?

[zeropointbug]

Originally Posted by AAngel

zeropointbug, I'm going to try to get someone to run by the post office for me. I'm going to be in trial all week and won't be ablet to. I'm borrowing a computer right now to clown around while I'm waiting.

As for the plug thing, I too was thinking about that. Just makes things more versatile. The only problem is that the plugs degrade over time. I know that I change mine often on my escs and motors. I don't like the idea of having to bend them to make them tight either.

I hope that my Quark gets here in the next week, if they fix it. The way my luck has been going, they might tell me that it's not covered for whatever reason. But...if I do get it back, I think I'm going to make a bank that will fit as many caps as I can within a length equal to that of the Quark. Then I can just epoxy the Quark to the cap bank and then epoxy that to the heatsink.

The epoxy is easy. The aluminum oxide powder can be found at hobby shops catering to rock collectors. They use the stuff to tumble polish rocks (go figure). Get the finest powder that you can. It costs around $8 for a 1lb bottle. I just mix up my two part epoxy and then add the powder until the epoxy turns into a paste that looks like thermal epoxy. They you just apply it as you would the epoxy. Once the epoxy starts to heat up, it flows really well and gets into all of the nooks and crannies. I won't say that it works as well as Arctic Alumina, but it does work well. It does move heat.

I do have to say that all of this leads me to some wondering. Actually, I'm starting to think that I'm full of it and all of my positive results have been figments of my imagination. I mean...if adding caps is all it takes to make things run so much better, why aren't the manufacturers doing it? I'd gladly go for an esc that runs cooler at the sacrifice of some space. Of course, I suppose I just have to keep in mind that we are running these escs out of spec; but hey, my MM got hot when I ran it in my T4 too.

I must have missed this post? :eek:

No troubles AAngel, please I don't want to be out of your way over the caps, do it whenever you can. As I don't have my Quark back yet anyways.

I don't even know where I can even get alum. oxide powder here, or for that matter a store that sells that stuff. I'll keep my eyes open.

The results you have seem real to me, if those are the temps you read... Like you said, the reason manufacturers don't use more, is space. We really just nee higher 'performace' caps, with lower ESR, and higher ripple current capability.


BTW, I though the MM had 220uF caps? I see in the pic they are three 330uF caps, that might be why the MM doesn't have as bad cap issues as the Quark.

gixxer, I meant to ask. How long have you been running your MM on 5S. I tried it this morning and the one that I got back from Castle will run 5S. Some of my others won't even go with 5S. They just sit and do nothing.

I kind of got scared and went back to 4S. Besides, even the 9XL on 5S was pretty nuts. Now I'm thinking that I'll have to try a 10XL. What's concerning me now, is the added weight of the 5S pack.

What packs do you run?

[BrianG]

The newer MM ESCs use different FETs (and maybe other support components).

[gixxer]

Originally Posted by BrianG

The newer MM ESCs use different FETs (and maybe other support components).

so which ones do you think will hold up better? reason I ask is I have been running 5s on the one I have but just ordered another to put in a truggy.

[zeropointbug]

I think running 5s on the MM is pushing it to the ragged edge. The caps on the MM are only 25v IIRC, so they most likely are being punched very hard. Has anyone had the caps blow on the MM? Or is it the board that something fries on it?

It seems like to me that the Quark has the most capacitor problems, and it has it's caps internally in case, I wonder if this has anything to do with it?

Well, the ones that I have that will do 5S are the older ones. The one I'm running right now is the first one that I got after their release.

Am I to assume that I don't have to worry about frying anything as long as it isn't cogging and things stay cool? I'm really liking the way this 9XL ran with the 5S. I just took it out because I've already blown up two MMs running 5S, but that was in the Muggy, which is a good 3lbs heavier than the 8ight T.