Inside the Quark 125, pics.

[smhertzog]

With the introduction of lipo technology, brushless motors, and bullet proof drive trains the potential for electric vehicles to surpass nitros in all catagories is at our fingertips. Be honest that is most peoples goal, to beat the fastest nitro in town or at the track and do it with a lowly electric. I love telling someone my truck is electric, have them go "Well try and keep up if you can" and then humiliate them.:027:
Right now the biggest limiting factor in the field of brushless 1/8 scale, in my opinion is the lack of a practical speed control that has both good programing and heat diissapation. I'm surprised that the companies who produce them dont make the few simple mechanical alterations it would take to fill the 1/8 scale void. The programing and electrical components are the hard part not the addition of heat sinks and or fans:032: At the same time I love screwing with things and enjoy making improvements so its all good.

JUST SAY NO TO NITRO

Originally Posted by smhertzog

JUST SAY NO TO NITRO

i agree! look at my avatar!

[smhertzog]

I see the pee baybee, Rock On:027:

[Serum]

It's redicilous you need those heatsinks.. (not saying you did a bad job Mate!)

time for castle to get their monster-maxx up and running.. This is hilarious..

[BrianG]

Lol, it is pretty funny.

I don't know if I'd leave them on there when running. That's a lot of weight to be bouncing on those sensitive FETs! BTW: why do you have a sink on the caps?? Caps should never get warm unless you are constantly charging and shorting them out, and that is simply from the current flow. The majority of the heat is most likely due to the FETs heating up, which heats the traces, which then travels to surrounding components (caps). Besides, caps, being round, don't have much surface area touching the sinks.

Like Serum said; it's not a bad job. If those don't keep it cool, the it's time to give up! :)

[smhertzog]

I got some runs in on my modified Quark this week before it rained. On two maxamps 8000's it ran for 23 minutes at full throttle (getting off it for the turns of course) around my oval track. The highest the fet area got was 137 f! It was the longest I have ever run my truck without having it thermal. Granted it was not 90 outside but full throttle for this length of time is about as hard as I can run it. Oh yeh no fans either.

Originally Posted by BrianG

Lol, it is pretty funny.

I don't know if I'd leave them on there when running. That's a lot of weight to be bouncing on those sensitive FETs! BTW: why do you have a sink on the caps?? Caps should never get warm unless you are constantly charging and shorting them out, and that is simply from the current flow. The majority of the heat is most likely due to the FETs heating up, which heats the traces, which then travels to surrounding components (caps). Besides, caps, being round, don't have much surface area touching the sinks.

Like Serum said; it's not a bad job. If those don't keep it cool, the it's time to give up! :)

The caps got up to 156 f so they do get hot even with air flowing over them.

[GriffinRU]

Sorry for late responses, but looks like I need to get Quark for testing :)

[smhertzog]

Originally Posted by Serum

It's redicilous you need those heatsinks.. (not saying you did a bad job Mate!)

time for castle to get their monster-maxx up and running.. This is hilarious..

Its only been what two years and counting?

The fets and boards wont be supporting the heat sinks the flat part of the angle will be the mounting base. The third picture is how it will sit in the truck.

[Serum]

I thought about not mentioning that Brian..

[BrianG]

Oops, oh well. I hope he doesn't take offense.

[smhertzog]

Originally Posted by BrianG

Oops, oh well. I hope he doesn't take offense.

Well funny and hillarious are kind of harsh but I've got thick skin. I put the sink on the caps so I had something to put the zips over without spreading them apart. When I get the heatshrink I'm removing them.

[BrianG]

That's good. I don't think I've ever seen anyone intentionally being rude (OK, maybe once or twice) on this forum. It's all fun! I'm sure you'll get a chance to poke fun at me at some point.

[Serum]

LOL!

yeah, only two years.. The computers are tripled in mhz value..

[neweuser]

I'm sure he will Brain! LOL :)

[BrianG]

Well, yesterday evening I got bored (since the site seemed to be down), so I took apart my Quark to replace the thermal pads with epoxy like others have done. I used the regular AS epoxy though - I just took care none of it landed on the board or any electrical contact.

The pads connecting the slab to the heatsink and the FETs to the slab were about 1/2mm thick, so if you take them off, you can't simply epoxy the existing aluminum slab because then the caps are too high and it won't sit flush. The existing slab is ~2mm so I cut a piece of 3mm aluminum instead. It fit perfectly.

I didn't replace the middle slab though. The two boards come part easily enough if you simply desolder the 4 pins holding them together on the motor lead side. The other connector simply slides apart. However, there are a few surface mount device pretty close to that area and didn't want to take the chance ruining them from excessive heat. And anyway, unless you find a way to couple that piece to the external heatsink, it is just functioning as a heat spreader and epoxying it won't help all that much IMO.

Once I got it all together again, I tried it out and now the heatsink acts different. Before, the heatsink took a while to heat up, got warm, and then took a while to cool off. Now, the heatsink heats quickly, gets hotter, and cools off quicker. This tells me there is less thermal insulation between the FETs and the heatsink so there is a more efficient transfer of heat.

All in all, I'm pretty happy with the results and think it's a worthwhile and fairly easy modification providing you don't mind voiding the warranty. Once the epoxy is on there and dries, it's not coming off.