Quark fried, blown capacitor...

Hey guys, I hate to be the crying baby of the bunch, but...I ran the truck this morning. It's getting HOT down here now. I ran for about four minutes and it thermalled.

I had had enough so I pulled the Quark apart and guess what I found. The pcb was moving around in the case pretty easily, so I started to peel the heat spreader from the case and get this, the adhesive on the FET side of the spreader just let go. It came off completely in tact. Check out the pic...



Do you see the indentions in the thermal pad from the FETs? You don't because they're hardly there. It looks like fewer than a third of the FETs were actually stuck to the pad.

Apparently, whatever lubricant it is that is used in the manufacturing process for the chips wasn't cleaned off.

What is up with S&T?

blipo, I like the sound of the way that your setup is running. I have a 1512 1.5Y coming in. It's very close to what you have. If I can get temps like that after 30 minutes of running, I'll be a happy camper.

Geez, you're running the smooth can motor and getting temps like those. Great!! I have a finned motor coming so it should run even cooler.

I like your mod. The only thing that bugs me about it is that those caps could get knocked off.

[suicideneil]

I would have recommended 220-330uf 35v 105c; lots of smaller ones being better than one or two big ones. You would also want a cap capable of handling a higher temp- 105c or more ideally. Wait and see what the others say though.

CG, I believe that the caps that we are using are rated to 105C. I suppose that whether that makes a difference to you depends on how hot your esc gets. Am I right? Someone else will have to pick this one up.

zpb, I'm glad that you finally got them. I was starting to get worried. I went ahead and did the mod with the stock case. I would be interested in a better case. What ever you do design, be sure that it holds the two pcbs together so that they don't separate during rough running.

I wish I had my Neu motor. I emailed Neu with this...

I recently purchased a 1512/1.5Y and had to send it back to you guys. USPS delivery confirmation says that it was received by you on Thursday, June 07, 2007. I don’t remember what I put in the included note, so just to be clear, I wanted to supplement the note with this email.



When I installed the 1.5Y in my truck, which is a Losi 8ight T, the performance was not what it should have been. After much tinkering with the gearing and running various battery packs (4S and 5S lipo) I came to the conclusion that one of two things had happened. Either I got a defective motor, or the motor that I got was mislabeled. Since the motor was running too well to be defective (although I could be wrong), I have a strong suspicion that I got a 1512 2Y, rather than the 1.5Y that I ordered.



I did call sometime this week and spoke with Carol (I believe it was) and she suggested that I ask that this matter be expedited so that I wouldn’t have to wait the normal two week turn around time to get another motor. I purchased a Quark Monster Pro to run with this motor, and it wasn’t cheap. Now I have a controller and no motor to run with it. I am anxious to get this thing on the track. Anything that you could do would be appreciated.



I would also appreciate an update as to the status of my motor.

They responded with this...

Thankyou received the motor yesterday afternoon, Carol

I was hoping that they'd tell me something that I didn't know.

Originally Posted by AAngel

CG, I believe that the caps that we are using are rated to 105C. I suppose that whether that makes a difference to you depends on how hot your esc gets. Am I right? Someone else will have to pick this one up.

Well, I doubt that I will get the quark past 85c (185f). Is it ok to mix the stock 330uf caps with the 1000uf ones?

Bye:018:

[BrianG]

Originally Posted by cemetery gates

Is it ok to mix the stock 330uf caps with the 1000uf ones?

That's fine as long as the cap you have is a low-ESR type or it might get hotter than you'd expect...

Originally Posted by BrianG

That's fine as long as the cap you have is a low-ESR type or it might get hotter than you'd expect...

I got these, 3 of them actually...

Bye:018:

[zeropointbug]

cemetary gates: They should work alright, if they are Low-esr, but I don't know of any, if any low-esr caps that have a running temp of only 85c. The more caps you add, the lower the operating temp they will have, as long as they are low-esr type.

BliPoRaceR: That is the ideal way to mount caps yes, but like AAngel said, it's too exposed for my tastes. The way AAngel mounted his caps on his MM, and Quark is more what I like, and the resistance from adding that little bit of wire is minimal. But you sure would want to keep the caps on the pcb (stock).

Looks like it would work very well though.

AAngel: If you do the mod, you won't likely be able to take it off the FET's again, maybe the case though. I am going to get a FET clamp machined first for now, until I get the case machined (and finalized). I'll use one of the heat sinks I have and mount it to it.

[zeropointbug]

Oh, yeah, I don't think those are low-esr caps. If I were you, I would not install them, they will most likely blow out and spill electrolyte all over your esc, and possibly damage it as well. sorry.

Originally Posted by zeropointbug

Oh, yeah, I don't think those are low-esr caps. If I were you, I would not install them, they will most likely blow out and spill electrolyte all over your esc, and possibly damage it as well. sorry.

ahh poop.....

[BrianG]

Originally Posted by zeropointbug

AAngel: If you do the mod, you won't likely be able to take it off the FET's again, maybe the case though.

You can freeze the ESC to make the epoxy brittle enough to pop off. I usually put the whole ESC in the freezer for about 20 minutes and then gently twist and/or gently pry the sink off. However, there is a real chance that you could damage FETs doing this, so do it at your own risk. I've done this to two Quarks and one MM with no issues whatsoever.

But really, why would you take it off once you do it?

[zeropointbug]

Oh right, you did say you did that. That's nice to know then, I was just thinking if he ever wanted a case machined?

[suicideneil]

Sounds like Carol is a robot, only capable of basic replies to questions. At least they got it okay; with any luck they will get you out a new one by early next week- fingers firmly crossed...

[suicideneil]

I would ask Cartwheels if he has any of the ones he bought left- they are the realdeal good quality ones.