Quark fried, blown capacitor...

[snellemin]

Angel, I guess I will have to find myself a busted quark and do the mod and see if it can be done. Might be fun. It will only be illegal if I sold their software, which they only have. There is nothing they can do if you purchased the product and modified it, accept refusing to honor the warranty. Isn't that what you guys are doing with these things in the first place. Adding caps, heatsinks, new cases. Those are all hardware mods, software mods can be done too. Same thing with 1:1 scale cars and modifying/reprogramming the ecu for better performance. If a piggyback rom can be build for more features, then why not.

[BrianG]

Originally Posted by AAngel

Brian, since when do we do things the easy way? If we did that, we'd still be running nitro.

snellemin, now that I think about it, it might be some sort of copyright infringement. Unauthorized use of software or something like that.

Now for the drama. I've managed to get my Quark to thermal twice today. All I was doing was running around in my front yard. I've run the MM harder for longer periods of time and never had any trouble. I took temps at the sink and along the aluminum case and got a temp of about 115, but when I temped the motor leads, it shot up to 140. I'm thinking that the FETs are a lot hotter than the case is getting. How can this be? A THIRD Quark and I'm already having problems. I'm really hesitant to open this one up to do the "mod," but I don't think I have a choice.

Maybe I should just sell the Quark and the Neu that I have coming back and get into a Lehner and run that with the MM. I just hate the thought of buying a motor from FD, but I'm getting to the point of putting all of this stuff aside and waiting for the technology to catch up.

lol, wellllll, the hardware mods are really the easy part. The software is a bit trickier for most. :)

I really think you have THE worst luck with RC I have ever heard! The only thing I can think of is the thermal pad inside isn't fully "stuck" so the FETs aren't making good contact. But three Quarks that have problems? Wow is all I have to say...

Brian, "wow" wasn't the word that I used. LOL

I'm tired of messing with it. I put the MM back into the truck and will run it until my Neu gets back. Then I'll pull the Quark apart and do the mod.

BTW, I did find the little note in the Quark manual saying that if you need finer low speed control, you should narrow the neutral range, so this is probably why zpb has such fine low speed control and I don't. They do warn that running a narrow neutral range can cause cogging. I'll have to try it.

O.K. I've been out of town unexpectedly, so....


Zeropointbug- Do you still want the quark I killed????

I have read somewhere that having extra CAPS only works good if they are "on top of" the FETS- I also read somewhere that it is BAD to have the CAPS "very far from" the FETS. (something about extra resistance - I dont remember) These were posts from consumers, nothing official...

I put 4 caps directly on my board where the other 2 caps connect. (1 next to and 3 across from. yes they stick out the side...) I replaced the sticky pads with thermal epoxy, and epoxied the case to the rcmonster heatsink (no fan but it is connected to the chassis and gets good air flow)

I just set up my new NEU 1512 2.5D smooth can with a 6200 5S4P maxamps in my 8ight buggy with 13/46 - the quark setting are all hot (Its a bit jumpy, I'll probly soften the torque)

I ran it HARD and FAST (faster then that buggy has ever been) for about 30 min - Motor = 165* or so, Batteries = 110*, Quark = 145* (it was 94* weather)

Some tuning and a motor heatsink will only make it better!!:017:

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?

Some pics of my mods...

the heatsink bolts into the frame at the engine mount holes (a bit of notching and it fits) the small piece of duct tape keeps the top cover from sliding forward...you can also see the CAPS are epoxied together (they are quite stable and fairly out of reach of the lid)




here you can see the notch in the side extends halfway across the bottom, exposing the solder point for the positive side of the CAPS and power input (otherwise this is unaccesable after the epoxy sets...) (yes i need new diff)





I like the low, centered COG with this install. The top 3 CAPS are along the center line and it all fits nicly under the top. Looks like I have a 'punk' Quark! (it has a mohawk)
Handling is spot-on and balance is very close. (need to change reciever pack and location for spot-on balance)

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.

[BrianG]

Originally Posted by AAngel

BTW, I did find the little note in the Quark manual saying that if you need finer low speed control, you should narrow the neutral range, so this is probably why zpb has such fine low speed control and I don't. They do warn that running a narrow neutral range can cause cogging. I'll have to try it.

Yeah, I narrowed my neutral range and can go VERY slow without cogging.

About the floating PCB; I kinda figured. Makes sense that it wasn't cooling if the FETs weren't even attached to the case! I know it's kind of a crappy solution, but S&T probably uses the pad so that they can remove it easily for service. Unfortunately, it doesn't last long. Once you do the "internal mod", your heat problems should be over. I say "should" because with your luck, it won't work. ;)

Adding caps should help even more...

[zeropointbug]

Yes, I had the narrow neutral range as well, that's why.

AAngel, my FET heat spreader was the very same as that! It was only touching half of the FET's, and the PCB moved around easy (slack). But I am thinking that the caps leads being GONE had something to do with it starting on fire.

Are you sure you don't want to wait for my custom quark case for yours? If not, maybe you should epoxy the top FET heat spreader as well, to increase thermal conductivity (power spikes).

I also received the 30 caps this morning, I have the day off so I will see what I can do for a cap bank.:)

Let me know if you are going to do as far as the 'mod', or if you might want my case.

Since we are on the topic of Quarks here...

I bought some 1000uf 35v 85c caps for my quark. Can I use these with out damage to my quark? Also I am putting a custom heatsink on it too. I'll post pics of it later...

Thanks!

Bye:018:

[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.

[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...

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: