Shouldn't it tell you what the voltage drops down to in the graph it gives you on the computer.

What voltage meter do you use? i've got a calibrated Fluke, and it's dead accurate according to that. (at least, my eagletree V1 was, i've got a V2 now and will do some measurements on it, i noticed they used slightly different components in it.)

You can calibrate the eagletree software with this voltage difference.

I did calibrate it once, after I did that, the voltage readout was only slightly diff, and it was VERY fuzzy, or NOISY. I'll try it again tomorrow though.

Also, AAngel, teh Arctic Silver thermal adhesive is non-conductive, and SLIGHTLY capacitive. I will take care applying this though, I am going to apply a thin layer onto the heatspreader, and then apply it to the FET's. And then I will do this again to attach it to teh Quark case. Then I will use regular Arctic Silver thermal paste between the case and the big @$$ heatsink.

About the heatsink, it is designed for very low airflow rates, the stock fan that came with it was only 17cfm or something near that. The airflow that it will see in action on a truck will be far greater than this. Not that I would need airflow anyways, it would do a VERY good job without it even.

I still don't get it. The sink obviously doesn't have any mass, so it can't pull much heat away from the esc before it gets to be as hot as the esc is. It has to rely on dissipating the heat into the air around the fins and then getting that hot air out and cool air in to repeat the process. I don't see how you can say that the sink will work without fans. So, this thin aluminum has all of these fins with the purpose of moving the heat from the sink to the air around the fins. So what happens when the air around the fins is the same temp as the sink itself and there's no fan to get the hot air out and cool air in. You have to move the air, because, as I said, air is a horrible heat conductor. The hot air isn't going to pass its heat off to the air around it.

I also don't know how you can say that the sink effectively dissipated that much heat with very little air flow. I'm going to assume that you are talking about the sink being inside of a computer case. If that is true, you can't say that there isn't a lot of air flow. Not only are fans in computer cases designed to move air, but they are placed inside the cases in places where they will be the most effective.

I'm also not getting your mentioning more fins working better with higher airflow and fewer fins working better with lower air flow. I can understand that if you have a given area with say 10 fins, you have to have a higher pressure air flow to cool it than the same area with 5 fins. It's kind of like flowing water through a pipe. With a 1" diameter pipe, you'd have to have a higher pressure/flow to move X amount of water in a given time than you would with a 2" diameter pipe. The larger pipe can flow the same amount of water at less pressure, but it is none the less moving the same amount of water. In this case, since you have lots of fins, the pressure of the air going through the fins is going to be higher than it would be if your sink had fewer fins. Are you saying that your sink is going to work better in this case with little air flow. If so, I'm not following.

I'm not trying to be argumentative. I'm must hoping to learn something.

It still seems to me that attaching the esc to the chassis is the best way to keep it cool. Lots of surface area, inspite of the lack of fins, and lots of mass to store heat until it can be dissipated. I wonder how long it would take an esc to heat a chassis up to 160 degrees F.

he meant there is always an airflow in a vehicle once it's driving.. I thought I was the only one who misinterpreted his words.

Ok, there is some sort of air flow while driving, but it isn't constant and it isn't always coming from the same direction.

Hey, lets just wait until he installs it and see what happens. Who knows, I might be making one of these next week.

Good point, Rene, centrifugal force can split magnet. And we seen number of motors with broken magnet not only from Feigao...

At 110C lots of things going bad, but at 130+C you will destroy magnet permanently, that what I was referring to. (I've got couple of those from my friends, saying they are weak... guess what they cannot even stick to refrigerator door :) )

About load, it is a dark territory with proprietary sign for RC, I guess.

For voltage measurment, keep in mind the correct is to measure voltage on the motor, not through connectors and FET's. Very difficult, but then do not expect exact matching with datasheets.

About the fewer fins working better with a lower airflow FAN I meant to say, also, when each individual fin is larger too. For a larger # of fins, they are usually small, and more densely packed, correct? So, for a given fan, it has to overcome alot more back pressure (because of surface area of fins, skin resistance), thereby reducing the overall amount of air actually traveling through the fins.

Another example, the PC i'm on now is highly overclocked, running a core 2 duo 2.4 overclocked to 3.6ghz. This takes upping the core voltage, and frequency, and some other settings.... anyways, the heat dissipation goes from the rated 65watt TDP, up to approx. 110 watts of heat at 100% CPU usage. The heatsink I am using is a large tower heatsink, anyways, it doesn't matter if I turn the heatsink fan ON, or OFF, the CPU temperature increases only up to 2 degrees. So then, the only thing keeping some cooler air inside the fins is the airflow through the case, which isn't a whole heck of alot.

This heatsink does have some mass to it btw, it's approx. 120 grams, or was it 140 grams, can't remember, it's on a previous post.

To get to the point, this heatsink will have more than enough airflow to work wonders if situated in a half decent spot.

Just for reference, I measured each fin, and came up with this surface area. Total surface area is about 1.23 square meters of area. The heatspreader is 2.5mm thick, the fins are .4mm thick, and the fin spacing is about 1.6mm.

The thin fins have something to do with not needing much airflow to stay cool. The amount of heat energy present with a Quark will won't need much like i've said before. It should have plento-airflow however. Also, surface texture has alot to do with surface resistance (obviously), they have a fine gold ball texture to them, with cuts down on resistance.

One last comment, when I was grinding this thing, after I took it off from heavy grinding, a few seconds, and the area I was grinding was only luke warm, before that I could not touch it; that was after moving the heatsink back and forth a few times in the air, not very fast either. It simply doesn't need much to work properly, it's an efficient cooler.

Any heatsink really has two parts; mass to pull heat away from whatever it is cooling; and surface area to dissipate that to the air. In my experience, tall fins don't work as well as shorter fins because the heat has to travel all the way up each fin. The only advantage to having tall fins is that more air goes through it.

It is more complicated...
Depends on material of heatsink (heat transfer properties...) so longer fins (higher differential temp) will do better jobs on materials with higher heat transfer rates.
As example copper will work better with long fins while aluminum not. But fins configuration and flow design can improve that process.
And you can make thinner copper heatsink with longer fins, but complexity and mechanical softness will be a major problem.

Yeah, material does matter. I can see copper having better results with longer fins while aluminum having better results with shorter but more numerous fins...

It's not that longer fins don't work as 'well' as shorter fins. If you want to look at it another way, from heat source, one side of fin, and temp measurement other side, it will lower the longer the fin. Longer fins will work better, only marginally better though. Heatsink design really is tricky, now there are fancy heatsinks (for CPU's) with a bunch of heatpipes and large amounts of fins. Heatpipes, if you don't know what they are, have distilled water, or alcohol under very low pressure, which vaporizes at a very low temp, which you know phase change takes alot of energy. Also, unlike a solid piece of metal (such as copper), heatpipes thermal resistance decreases as length is increased.

For this heatsink, it's good that the fins are of decent length, for one: to catch air, and two: inside the fins, there is a certain amount turbulence which spreads around the heat energy down the length of the fins.

I am thinking of mounting it in front of the transmission right behind the front shock tower. If not enough room, other side of chassis, where it will still get enough airflow.

I just did a little experiment with a 600 watt heatgun, with a low speed fan. With the heatgun of the heat spreader for almost 1 minute, with the fan running (rated 19cfm), after this period, the heatspreader was quite warm, I would guesstimate it was 45C (113F), and VERY quickly cooled down to room temp within 15 seconds.

Not convinced yet? :032: :005:

It wouldn't make much of any difference using copper fins rather than aluminum fins. I've seen this lot's with CPU heatsinks, copper version of the very same one, was only 2-3 C lower temps than aluminum one. The most important part is the heatspreader, which SHOULD be copper, as that is where the highest heat density is, right?

Nope, not convinced! ;) You forget that I abhor the use of fans for R/C applications, so the majority of the tall-fin benefits are lost. Agreed, CPU applications are much different...

Which part are you not convinced about?

How about this, once I get my thermal adhesive, my thermal probe (infrared), and my truck up and running, we will see how well it works. I know with absolute certainty that this will work super fan-taz-magorical.

Don't forget about air convection through the fins too (without fan, or direct airflow), as I also tried using no fan with the heatgun. I couldn't get it over a temp that I couldn't put right to my cheek right after, from about 1 minute of blowing the heatgun directly on the heatspreader, about 2cm away.

even more complicated, because now you add gas to equation and gravity and direction and sensitivity to temperature range. What works or doesn't work for CPU is not true for every application. With heatpipes selecting correct fluid is very important, more important that pipe is long enough that fluid easily goes through all stages and there is some in liquid form not in gas othewise it stops working...

They use wicking in heatpipes now, the texture inside the pipe. Also, these things are very efficient in transferring heat to some other place (fins). gravity has little to no affect on heatpipes now.

Why do you think this is SO complicated? Heatsink design is trucky yes, but the basic understanding of heat transfer is simple.

Because, I've done some designs in the past and most of them didn't pass mil specs due to the little gravity effects and other heat related problems. And if it is simple then why there is no simple heatsink for CPU, but we see all kind of crazy designs flying around while copper and aluminum are still have the same properties with air included.
I didn't said that it is less efficient, I said it is complicated and has its limits due to its better efficiency in limited range of applications or temperatures.

Well, to be honest, MOST heatsinks for CPU nowadays are just designs, that's all they are. Lot's just looking cool, decent cooling capabilities, nothing great. Most heatsink design is coming from PC industry now.

Like i said, heatsink design is tricky, as there are several ways you can make it perform: such as LOT'S of airflow, NOISY, and guaranteed to work, with moderate fin count. OR another extreme, like these large tower heatsinks, using heatpies densely around the CPU, then efficiently transferring the heat as vapor to a large set of fins. This method works amazingly well, and better uses a given surface area of fins, than a simple heatspreader, fins design.

What kind of experiment did you do?

I figured I'll post here, instead of making a new thread, not to take away from zero's posts, but it's very similar..

ok, so i'm hoping my motor mount will be in tommorow, and i'll be ready to go, so i decided to do some last minute mods, to make sure my lsp's off on the right foot..

started to take the quark apart, and i'm stuck..
http://img261.imageshack.us/img261/1...0135pj8.th.jpg http://img261.imageshack.us/img261/4...0133wa6.th.jpg http://img261.imageshack.us/img261/1...0138ep5.th.jpg http://img261.imageshack.us/img261/2...0139ee1.th.jpg http://img45.imageshack.us/img45/687...0140yg6.th.jpg

I know there's another set of pins/jumpers tward the end with the motor plugs, but i can't seem to un-plug them, so not sure if there's something else in the way or not.. and the controller seems to be VERY secure to the bottom of the case.. so what do you guys think? my controller's a few months old now, so i'm guessing it's the same as all the others with heat problems, but i've yet to get it hot, because it's been in my onroad car.. I've got a big selection of computer heatsinks to choose from, and am thinking about ditching the quark's case all together.. but someone want to re-describe how to dissasemble this? sorry for being thick, but it just doesn't seem to want out of it's case :002:

The whole thing is held by the sticky thermal pad at the bottom. When I removed mine, I took a small flat-bladed screwdriver and gently pried the heatspreader off the case. Then, even more carefully, pried the heatspreader off the FETs. Gotta be careful here as the casing on the FETs can break.

You could take it completely out of the case, attach a larger heatsink, wrap the rest of it in heatshink, and then cut a hole for the heatsink like how the BK Warriors are built. But, having a nice metal enclosure is one of the nice things about the quark as it helps to protect everything else.

Oh, and those pins connecting the two boards are soldered in. They are very close to some other surface mount devices so be careful if you decide to desolder the pins! Those nearby surface mount parts can easily be damaged by heat and there goes your $280 controller!

Hey, yes, like Brian said. You just have to get a small screw driver where the battery power in wires come in, and put moderate pressure up, it should start crackling and start to come off.

THen what I did to take the heatspreader off the FET's, was use the plastic end piece as a leverage spot, and put the screw driver tip just under the pad (where there are no FET's) and do the same thing. However, it's stuck on the FET's better than it is to the case, so just constant pressure up with leverage on the screw driver, and it should slowly start crackling and lift off.

Would you mind posting pics of the heatsinks you have? I'm curious what you have.

hmm and where's the part that's not getting a good thermal contact? I just kinda felt like jumping into this when I woke up.. 3mm shim's needed where? because it all seems like it's got good contacts between the fets and the bottom of the case.. i don't see it moving anywhere.. debating if I should just throw a heatsink on it, and see if it thermals, and worry about dissecting it later, if problems arise? I tried w/ a small flathead, but the dozen or so flatheads that are small enough, aren't long enough to reach the metal shim.. about 1mm too short =\

here's the heatsinks I've got at home.. there's an AMD Athlon stock HS on the left, and the rest are either older CPU heatsinks, or northbridge heatsinks.
http://img453.imageshack.us/img453/3...0136wu2.th.jpg

and here's an old hard drive with some heatsinks.. I just think it's funny to have heatsinks on a 5400rpm hard drive lol
http://img105.imageshack.us/img105/4...1391tc2.th.jpg

then i've got some old motherboards and videocards (tnt2's and voodoo3's) out in the garage, with a wide array of heatsinks.. if I need..
at my work, we've got alot of old computers, w/ a very diverse selection of heatsinks.. you should see how big the heatsinks are on some of the older servers.. oct-cpu servers and such have 6"x6"x4" or so heatsinks :)

Hmmm, well that green one looks like a great one to use! With a little fan if you want?

The Athlon heatsink is kinda tall, and too heavy, IMO. Although, would work very well!

You've gotta have a small screw driver that can do this!? :032: :005:

I assure you, the FET's are not well thermally coupled to the case at all! First, the thermal pads are crap, not for high output applications, and there are two of these to go through. Second, where it attaches to the case, it's only touching along the two outer edges, about 1/4 each side. It just can't escape.

BTW, how come you bent down the side of your Quark case?! :002:

haha prying.. it's straight again.. if I did it again though, it'd most likely snap off.

i'll take it with me to work tommorow, and get it apart.. the AMD HSF is pretty big.. but I'm thinking about securing it to the controller.. and then have the fan on the side of the HS... and mount the HS on it's side, behind the steering servo, in front of one of the battery packs.. we'll find out how well that works in a few days i spose.. if not, the green one's the best bet.. I really need to get/make a 12V mod, so my fans run at 12v.. if you notice the deans connector on the UBEC, i've got one of my 12v fans running on 6v right now.. but it still pushes more air than the fans on the novak units lol

Quark problems??
 

Does this happen alot?? I was looking at a Quark and NEU motor combo but if it can't do 4S lipo's for more than 5 minutes I don't want to waste my money. will the Quark last the runtime of the batts in an E-maxx?

Problems can be found here under "Limitations" and at the bottom check "See also" and "External Links" heat-pipe selection guide

As far experiment - you know the answer, right :)

I'm running the Quark on 4s with a 2600kv Neu on my buggy and it runs cool with a simple small heatsink (no internal mods yet). The internal mod just makes it run that much cooler.

And just to clarify about the way the internal pads work and what needs to be done to replace the existing heat spreader:

http://scriptasylum.com/forumpics/quark_mod.gif

The drawing above isn't exactly to scale, but you get the idea...

The stock heat spreader is 2mm thick and each pad is 0.5mm thick. This thickness is needed so the capacitors clear the case. Once you remove the pads, there isn't enough thickness for the caps since the epoxy is very thin (practically 0mm). So, a new spreader that is 1/8" thick works perfectly.

NICE work Brian! Very easy to understand.

The thermal pads and the slab, I measured 2.85mm together with a digital caliper. But I suppose 3.175mm won't hurt...

Do you know of any angle copper or aluminum that could be used to connect the top and bottom FET's together?

I'm almost tempted to make a water block slabs for the thing! And put a rad out front of the vehicle, now that would be the ultimate! :027:

I am just trying to figure out a way to keep this 540 7Xl cool! I should have just got the smooth can version and made my own water jacket for it. Then the entire vehicle would be water cooled.

Does anyone know how I could make the fins on the 540C can into a water jacket?

Thanks! I thought it would be easier to explain with pictures. Unfortunately, I didn't take pictures of the process when I did it. Mine measured just under 3mm (like 2.97 IIRC) - maybe the pads weren't as compressed on mine. Dunno. But 1/8" works well.

I didn't touch the middle FETs since I didn't even have any idea how I was going to couple that heatspreader to the case. I figure the better cooling on the other side would help leach the heat away from the whole board improving cooling all around.

For your water jacket, just wrap some copper tubing around the fins. :)

GriffinRU, I know all the limitations about heatpipes...

They really do have to be tuned to a specific operating temps, and ambient temps.

I know this first hand.... frozen CPU.... i've done this before in the winter when it's -35C outside, with the PC case in the window, the CPU will get to below O temps, by doing this, you can get VERY high overclocking levels! Last year I took a Pentium 4 3.2 Northwood (130nm) to a sky high 4.25ghz! That was with a solid copper heatsink though.

THIS year, with my new PC with a large tower heatsink (Noctua NH-120) I did a cold window test, although only -15C, and the initial temps went down to about 5C, after a few mins of running the temps started to go up and up, until it hit 55C... hotter than what it gets at room temp! So they are definately sensitive to ambient temps. My guess is that the vapor just froze up and physically BLOCKED the vapor chamber.

I guess it all depends on the pressure of the working fluid for a certain temp range. Diameter, and length have to do with energy transfer.

Every couple months, manufacturers come out with new heatsinks, most all the new ones are heatpipe ones. The new Thermalright Ultra-120, and their IFX-14. The IFX uses biggest 8mm heatpipes, and uses 4.

If you had the room, the more heatpipes you can fit at the heat source and lower vaporizing temps the better, and evenly spacing the pipes into a fin radiator.

It's all in the design!

LOL, it's in the design of the CPU! Make a more efficient CPU and you won't need those exotic cooling solution. ;)

Dude have you tried liquid nitrogen cheap and efficient, you will be surprised what you can do with logic in liquid nitrogen :)

The only problem what is good for CPU is not the same for buggy running at open, not in air-conditioning environment...

I am sorry but I think we done here. Information was for everyone do not take it personal.

Exactly! The record so far was the Pentium D 840, this thing was a SPACE HEATER! :005: :026:

The new Core 2 Duo's are quite a reduction in heat output! And doubling performance at the same time.

But a better heatsink, means higher clock speeds, IF you overclock, but enough of that talk...


"I am sorry but I think we done here. Information was for everyone do not take it personal."

Who is taking anything personal?

Looking on all this mighty heatsinks I am thinking how much power dissipates on Quark?

Lets say 7XL draws 50A continuously, so at 0.00036Ohms at 25C power loss should be 0.9W
Next say at 100C derating factors bring us to 3 times up, so 0.00036*3=0.00108 - power loss now 2.7W

To get even 10W requires Rdon to be at 0.004Ohm which is 11.1 times higher then at 25C.

So, is the ESC efficiency so low or there is something else?

I've wondered that myself, but it may simply be the way the Quark operates. I made a thread a while back showing the differences on how the MM behaves vs the quark when the motor is forced to a stall condition. Basically, the MM simple increases the throttle until the motor finally moves (which is bad IMO and the root cause of a couple of them burning up) vs the Quark being MUCH more gentle about it. I know this is mostly firmware programming, but maybe the engineers at S&T decided to decrease the slew rate a little for control reasons? And if you decrease the slew rate, there is more time where there is an actual voltage drop AND current draw creating more power loss. I really don't think it's a matter of raw FET specs. But, even in your example, 10W is actually quite a lot of power to be dissipated on a small heatsink.

And, I've not found a reason to get crazy with heatsinking - just enough to pull the heat away from the case and dissipate it to the ambient air, which should have enough flow in a moving vehicle to do so effectively. I don't like heat - at all - so when I say the ESC isn't hot, it isn't. To me, 130*F is too much.

I don't run a heat sink on a quark 80b. I have great temps on my gmaxx.
That is one huge heat sink though.

Yeah, I've never thermaled before I added any extra sinking, but I thought it got too warm for my liking. I guess I'm just funny that way. :)

BTW: What's up CHC. Haven't seen you around a lot lately...

LOL, okay now I know... are you sure you know what your saying?

The physical resistance is only PART of the heat output. Most of the power loss is the design of the motor, and how well it transforms the power input to it.

What is 2.7Watt? That would be barely warm to the touch....

The esc I am guessing is somewhere between 92 - 97% efficient. Couldn't tell you, it's probably about 10 - 25 watts of heat, which is alot for these little FET's to dissipate, that's why they can get so hot because of insufficient heatsinking. With a proper heatsink, 25 watts of heat is a piece of cake to keep the temps down (~15C Delta).

Is there a misunderstanding here about motor efficiency.

I think some times the driving styles effect the heat issues as well.

Not alot brian. Just figured i would show up and throw some input around. :D