Is there a Quark 125B thermal problem? - Page 3 - RC-Monster Forums

BrianG · 11.30.2006, 07:23 PM

Yep. The existing slab is ~2mm thick with two pieces of thermal pad (~.5mm each) for a total of 3mm. If you remove the pads, you remove ~1mm of thickness and then the caps prevent the FETs from sitting flush on the case. And yes, the thermal pads are what holds the whole circuit to the case.

I suppose you could waterproof it while you're there anyway. You'll have to use some material that won't weaken or get soft when substantial heat is applied, that won't get brittle after time, and can endure the vibrations and jarring. Maybe epoxy may be a better choice?

You can do whatever mod that makes you feel good. :) I just had good luck with what I did, but I'm sure there are other ways to get the same (or better) results.

Good luck!

jhautz · 11.30.2006, 07:51 PM

Quote:

Originally Posted by BrianG

I suppose you could waterproof it while you're there anyway. You'll have to use some material that won't weaken or get soft when substantial heat is applied, that won't get brittle after time, and can endure the vibrations and jarring. Maybe epoxy may be a better choice?

Shoe Goo ???

zeropointbug · 11.30.2006, 10:24 PM

I think Silicone would be perfect then, once it cures it's then almost the consistency of the silicone wire insulation (prob more flexible).

Also, are you sure you have to unsolder the motor wires? Can you not slide the top cover left off of it? Where exactly is the cap. near the esc button?

BrianG · 11.30.2006, 10:30 PM

jhautz: I tried Shoo-Goo on something else and it tends to get brittle and seperate from the thing it's trying to seal. I would think something flexible, yet heat/water/motion resistant would be better IMO as long as it bonds well.

I unsoldered the wire simply because it looked easier. You might be able to work the end off without unsoldering, I don't know. I guess you'll just have to try it. :)

The caps are on the power wire end (since that is where they are used).

zeropointbug · 12.01.2006, 01:35 AM

BrianG, i tried taking the cover off without unsoldering the wires, i couldn't get it to come off. So i unsoldered the wires, and slid it off and noticed that the only thing stopping you from doing it the other way is the little see-threw plastic window for the LED's, it hits a little IC beside it.

Anyways, i go it all apart, except for taking it off the case. I notice that there is two alum. slabs one on both side of the bottom circuit board, and it looks like they are the same FET's ???!!! What!? Do you know if this is true? Or are they for something else? CHeck the pics, if they are the same FET's then maybe all they need is some heat spreading? And the thermal pad is just to attach to the case? It also doesn't really look like the pads are .5mm, they look thinner than that, maybe .3mm? I don't know... I don't want to take it apart yet, i don't have Thermal Adhesive at the moment, i'll pick up some Arctic Silver stuff when i can.

So is there two layers of FET's on the two sides of the power board?

02:12 AM

You should really use the Arctic Alumina from Arctic Silver to bond the aluminum slab to the FETs. "Arctic Alumina Adhesive is a pure electrical
insulator, neither electrically conductive nor capacitive." here is a link http://www.arcticsilver.com/arctic_a...l_adhesive.htm . When I did mine I could not find it locally anywhere so I had to order it online. PC shops online are the best place to get this stuff. It is good stuff, but it's a perment bond!

I only bonded the outside FETs to the slab and case and did nothing on the aluminum slab that is sandwiched between the boards.

Your pretty brave doing this on a brand new controller! :027: but it does make a difference especially for bigger vehicles. It seems to cool quicker and overall more efficiently.

zeropointbug · 12.01.2006, 02:25 AM

Hey, just to add, it appears once i took a closer look, that the slab attached to the case is only touching on the edges, it's not even touching in the middle...

Yes i was planning on using Alumina.

Do you think this mod is necessary for a 1/8 emaxx buggy? It will weight in at about 7.5 lbs. What do you think?

12.01.2006, 03:35 AM

hello zerpointbug,

may i ask you, are you try setup your esc the Drag Brake function yet?
it's at menu Table 3.2-3 and Table 3.3-2 , would you feel free to test it
and try power off then power on, the function will off , if you set ON before.

i have 5 esc 2 new(3color wire), 3 old(white color wire), 2new esc can't store memory (just Drag Brake) , 3 old esc is normal.

i want compare your esc with me.

Thank you..

neweuser · 12.01.2006, 10:30 AM

Quote:

Originally Posted by andywpj

hello zerpointbug,

may i ask you, are you try setup your esc the Drag Brake function yet?
it's at menu Table 3.2-3 and Table 3.3-2 , would you feel free to test it
and try power off then power on, the function will off , if you set ON before.

i have 5 esc 2 new(3color wire), 3 old(white color wire), 2new esc can't store memory (just Drag Brake) , 3 old esc is normal.

i want compare your esc with me.

Thank you..

How did you get 5 of them! WOW! Do you live in Thailand by any chance? LOL

BrianG · 12.01.2006, 11:04 AM

zeropointbug:
The cover plate does slide off if you pop that little clear piece, but it's still kinda hard at first. So, I just popped off one side and it came right out. It's plastic so it bends a little.

The slab in mine was touching the middle as well. The pad covered the entire slab on both sides.

The inner slab is actually for another set of FETs. There it acts like a heat spreader. Ideally, you would find a way to attach that slab to the case as well, but it would be a little difficult. Smertzog (or something like that) installed huge heatsinks on his, but doesn't use the case anymore.

As far as if it is necessary for your emaxx: Improving its thermal characteristics is good for ANY vehicle, but makes more of a difference with heavier ones. Cooler devices means better reliability and longevity.

andywpj: Wow! You must really like the Quark controller!

neweuser · 12.01.2006, 11:08 AM

Quote:

Originally Posted by BrianG

andywpj: Wow! You must really like the Quark controller!

My sediments exactly!:005: 280.00 x 5 = 1400.00!!!!

12:27 PM

Ha actuality i have 5 quark two HV110 and two mamba max. because i convert my all truck to BL.

i thinking quark low speed startup smooth better over other esc.

By the way, about thermal pad , i use 37mm*27mm* 3mm copper to replace aluminum and use A.S
sticky fet and case.
very very good. but fet and copper sticky after you can't move them and no warranty, you must be know that.

Serum · 12.01.2006, 12:40 PM

You signature is funny Andy.. LOL

zeropointbug · 12.01.2006, 12:52 PM

Well, im stuck in a bind! They should have used small HeatPipes to conduct the heat from the top set of FET's to the bottom ones and case. Why would it make such a difference cooling only the bottom ones?? This is weird.

I THink i might just lap the bottom of the case and use A.S. to conduct heat away into the upper Alum chassis brace on my vehicle...

I live in Canada, so even in the summer, i would only drive the car max 25 degrees Celsius, and i don't drive that hard either. So maybe just doing what i will do will be good enough?

Do you guys that have dont the mod, do you get noticeable longer runtime?

BrianG · 12.01.2006, 03:34 PM

Really, the stock setup should be "good enough". If it thermals, then Quark support should be notified. These types of mods are done to make it run more reliably, so any mods are bound to make improvements if done right.

I haven't noticed any runtime differences, and I can't see how that would be affects. What it does do is allow you to run much longer (just about indefinitely) without worrying about whether it will thermal. If that's what you mean by runtime, then yes, it runs MUCH longer. :)