Inside the Quark 125, pics.

[BrianG]

Serum: I thought about doing pictures, but there were already pictures of the internals posted previously. I didn't do anything earthshattering; I just removed the internals, then removed the thermal pad on both sides of the spacer aluminum, and epoxied that to the FETs, then to the case. Since the pads were 0.5mm each and the slab was 2mm, I needed to use a 3mm piece instead. And, you are correct, I didn't do anything to the middle piece. Like I said, unless that one is coupled to the external case, nothing done will have much effect.

Cartwheels: I think there are two reasons why they use the pads: ease of assembly and warranty work. If the FETs were epoxied to the case from the get-go, warranty work would be all but impossible. There are other forms of thermal tape which may work better, but the stuff they used is actually better than most tapes I've seen. Unfortunately, it doesn't stay connected under the dusty and vibrating conditions.

[Serum]

Why don't you use a thicker aluminum plate, glued to the case with thermal stuff and use silicone paste or a thin pad?

[BrianG]

Silicone paste doesn't work well if the surfaces move around at all. Pads are not as effective. If there was a way to make absolutely sure both surfaces stay put under use while pressing the surfaces together firmly, then regular thermal paste would be an ideal choise. Since that isn't easily feasible using the stock case, thermal tape would be the next choice, but it's not as effective and still prone to the same problems as the original tape. So, that leaves thermal epoxy. The only downside to that is that you can't seperate them again. In the end, it's all about compromises.

[smhertzog]

Test drove my quark with the angle heat sinks today. It was just over 80 outside. I ran it for just over 12 minutes, none stop and as hard as I could around my track. The Quark was 139 on the hottest part of the angle and 144 were the motor wires go into the board. The motor was 172 so I didnt pop in another set of batteries. I was running a 7xl orion 4800 lipos and 20 66 gears with my buggy diffs so I went to 22 66 to see if it would lower the motor temp. After about 10 laps I flipped it going over a jump and decided to take some temps. The motor was 181 and the angle on the Quark was 151and the wire ends were 150. Looks like I need a better motor.

thinking about it if i was quark i would epoxy heat spreaders to the fets and then drill tap a thread in those plates probably do that first though then use a paste and simply screw the heat speader to the esc case to apply presure for the paste to work.

You could even use a bit of angled alu like smhertzog and bolt that to the side of the case in the same manner with it epoxied to the fets.

This way you can still take the unit apart for maintenance.

[neweuser]

How are you guys getting the Quark apart anyways?

[smhertzog]

It came off on its own were it was taped to the case. It was just flopping around in the case. The heat spreader was on good and took a little finesse. It runs much cooler than it did with a fan and heat sink on the case. I just wish it had an adjustment for the motor timing so I could get my motor temps down. Its always something isnt it?
If the punch control and the brakes had two more lower settings it would be nice too. All in all it is a very nice controller it just needs a little help in the thermal area when your running high amps or high volts on a 10+ truck.
I'm alittle curious about the new Mamba Maxx. I have a brand new in the box Quark and a Quark with like two runs on it. I'm going to Ebay one of them to get some cash to buy a Mamba and check it out. I'm running 4s lipo and a two pole motor which is the only short coming of the Mamba maxx (low volt rating and no 4 pole motors). Its cheeper than buying a Neu motor and I love my Mamba 25.

Originally Posted by neweuser

How are you guys getting the Quark apart anyways?

If you are talking about how to open the case, in the center on of the top plastic piece between the plastic and aluminum casing, stick a small sharp flat sharp screwdriver, opening the aluminum casing just enough for the top plastic piece (there is even a small slot there like it was made for a screwdriver to fit) to come outward.

I'm alittle curious about the new Mamba Maxx. I have a brand new in the box Quark and a Quark with like two runs on it. I'm going to Ebay one of them to get some cash to buy a Mamba and check it out. I'm running 4s lipo and a two pole motor which is the only short coming of the Mamba maxx (low volt rating and no 4 pole motors). Its cheeper than buying a Neu motor and I love my Mamba 25.

I love the Mamba Max, but the Quark I believe just feels better overall for 1/8. When I had the MM in my buggy over all it works pretty good, it just feels smaller. Not quite as much take off power. Occasionally, from a standstill to full throttle would give you just some clicking as if I was holding the buggy. Hard to explain. If you have a light 1/8 setup it would probably be ideal.

just want to point out that as far as i know mamba max controllers dont have a problem with 4 pole motors.
Glassdoctor was running a neu motor on one in his 1/8th buggy conversion and he says it works great i am not sure what settings he uses but i suspect that you need to set the timing settings higher as you normally do.

Yes, maybe I do. I had it set on low timing. I have a secondary 1/8 buggy that I'm now running the MM in. It is an old MBX. It only has enough room for one 4s lipo. I have it setup with the MM and a Neu 1512. It's nice and light and seems like it is very efficient, I think it ran for somewhere close to 15 minutes. I'm going to try the normal timing setting on the MM to see if there is any change, it really is an amazing little controller.

[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]

Originally Posted by smhertzog

Sorry here are the pics

Looks like your caps are dead already...

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! :)

Caps will get warm, because they eating high-voltage spikes from FET's transitions left and right. And they have ESR value which will tell you how much power loss (heat) will be dissipated by cap. And their ESR goes up with temp...

[GriffinRU]

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

[zeropointbug]

Originally Posted by GriffinRU

Looks like your caps are dead already...



Caps will get warm, because they eating high-voltage spikes from FET's transitions left and right. And they have ESR value which will tell you how much power loss (heat) will be dissipated by cap. And their ESR goes up with temp...

ESR, yes, the lower the better, it's kinda like inductance in an AC circuit, along with physical resistance. That's why audio grade caps have ultra low ESR, the very high end systems anyways...

That Quark looks VERY exposed! Too much for my blood!

I am going to try and make my heatsink mod get the top FET's attached to the bottom of the case for additional cooling.