TEC cooling an electric (540) motor

[D_o_S]

Hiya,

well this might be a little off topic, but I figured you guys could help me out. Basically, I want to design a TEC cooler that will cool a 540 size motor for my RC car before the run (I put the cooler on the motor for 5 minutes, it chills the motor, then I take it off and drive). I've heard all sorts of marvels about doing this, so I think I'm going to give it a try. First, a company called Much More released a TEC cooler, which you can see here:

http://www.teammuchmore.com/index.cfm?fuseaction=pub.default

I plan to build something similar, here are the parts I have:
AMD BOX heatsink
80W Pelt
Cold plate
Power supply

Now, I'm going to put all this together... that's not my concern though. My main concern is can this have any adverse effects on the motor? Like the magnets becoming demagnetized? Or bearing oil drying up? Any any way in which I can prevent the above?

Thanks for any help and advice.

[MaRtIe]

Hiya,

well this might be a little off topic, but I figured you guys could help me out. Basically, I want to design a TEC cooler that will cool a 540 size motor for my RC car before the run (I put the cooler on the motor for 5 minutes, it chills the motor, then I take it off and drive). I've heard all sorts of marvels about doing this, so I think I'm going to give it a try. First, a company called Much More released a TEC cooler, which you can see here:

http://www.teammuchmore.com/index.cfm?fuseaction=pub.default

I plan to build something similar, here are the parts I have:
AMD BOX heatsink
80W Pelt
Cold plate
Power supply

Now, I'm going to put all this together... that's not my concern though. My main concern is can this have any adverse effects on the motor? Like the magnets becoming demagnetized? Or bearing oil drying up? Any any way in which I can prevent the above?

Thanks for any help and advice.

Sorry to Spam your thread, just wanted to say its nice to see someone with the same hobby as me!

[Thrilla]

You should get a better HSF for a 80w TEC
Cold plate isn't really necessary for motors, just find some strong aluminium plate to clamp the TEC

I think cold temperature only makes the motor spin faster and work better, correct me if I'm wrong.

[D_o_S]

You should get a better HSF for a 80w TEC
Cold plate isn't really necessary for motors, just find some strong aluminium plate to clamp the TEC

I think cold temperature only makes the motor spin faster and work better, correct me if I'm wrong.

I've had my TEC on the AMD HSF and it cooled quite well... again, I don't really need xtremely low temps... or what is the safe range? If I can go as low as I want, I'll get a new heatsink.

Also, the motor doesn't produce any heat while being cooled.

[MaxxxRacer]

D_o_S, I'm no EE, but I can tell you that the lubes that are in the Reedy/Trinity motors are designed to run in the 45C range, so for the first few laps the motor will probably be a bit sluggish while the lube is warming up.

The SMD caps on the top of the motor will last a big longer (they last longer in cooler temps)

The resistors also wont be effected much at all, so no gains there either.

Also, when you break in the motor, where the brushes touch the armateure, this matting surface is formed at higher temps and will deform slightly if run at relatively low temperatures. but again, you can only get the motor so cold and its only for a short period of time.

If you were to attach the cooler on to the motor while you broke it in and during a race (bad idea for your laptimes), the cooled brushes might make better contact with the armature, but I dont think there are much of any gains to be had there either.

I also did some reading on temps of DC can motors and found that the only reason that you need to keep them cool is so that the windings dont fail. If they reach a certain temp the winding will actaully come apart, and you can imagine what would happen to the motor. BUT the R/C motors of late are getting better and better air cooling with the improved can designs, so this is really a moot issue.


the last piece of evidence that poitns to this being a bogus product is the fact that none of the top racing teams are using them. If you dont see Brian Kindwald (or other top racers, whos names escape me) sporting one of these gadgets, its probably because they dont do jack.

[D_o_S]

D_o_S, I'm no EE, but I can tell you that the lubes that are in the Reedy/Trinity motors are designed to run in the 45C range, so for the first few laps the motor will probably be a bit sluggish while the lube is warming up.

The SMD caps on the top of the motor will last a big longer (they last longer in cooler temps)

The resistors also wont be effected much at all, so no gains there either.

Also, when you break in the motor, where the brushes touch the armateure, this matting surface is formed at higher temps and will deform slightly if run at relatively low temperatures. but again, you can only get the motor so cold and its only for a short period of time.

If you were to attach the cooler on to the motor while you broke it in and during a race (bad idea for your laptimes), the cooled brushes might make better contact with the armature, but I dont think there are much of any gains to be had there either.

I also did some reading on temps of DC can motors and found that the only reason that you need to keep them cool is so that the windings dont fail. If they reach a certain temp the winding will actaully come apart, and you can imagine what would happen to the motor. BUT the R/C motors of late are getting better and better air cooling with the improved can designs, so this is really a moot issue.


the last piece of evidence that poitns to this being a bogus product is the fact that none of the top racing teams are using them. If you dont see Brian Kindwald (or other top racers, whos names escape me) sporting one of these gadgets, its probably because they dont do jack.

Thanks for the informative post.

So you're basically saying that I'm better of with a normal heatsink on my motor? Or with no heatsink?

I'm in the process of getting one, and I don't know if I should go for an aircooled one (http://www.tamiya-shop.cz/inshop/scripts/Detail.asp?kat=63051) or if I should get just the passive part... or not get anything at all, and run my motor without a heatsink (its a Nosram 17x2)? Up to this point, I've been running it without a heatsink without any problems, but the brushes do get quite hot (as well as the motor)...

[Holst]

I wrote this reply yesterday but the foryum broke as I clicked reply :P

I used to have a can of freeze spray that I used to chill my stock motor before a race. Did give you more punch for the first minute, might also have made brushes last a bit longer as they were not super hot for quite so long.

I would buy some freeze spray (its for diagnosing faults on electrical boards) and test it out before you make a TEC chiller.
If you cant get freeze spray then airbrush propellant gas (i think its butanol) will work pretty good, just turn the can upside down and let the liquid evaporate onto your motor.

You might also want to try com drops that will soften your brushes/com and give you more power. But dont do this on a modified motor, you might kill the com.. stocks tend to cope better with drops.

As for the chiller .. I think it will work a bit, but im not sure how low the temps will get unless you leave it for ages.
A big loud fan will help allot on the heatsink.

How are you going to mount the motor to the chiller?

You really want to be chilling right up untill 30 seconds before the race starts .. thats why I used freeze spray, you can just blast the can with it.

I should point out that when I was racing stocks competitively I would replace the motor after about 4 meetings, or 100 minutes of use.
I would rebuild after every run for cleaning and would skim the com often (usually after round 2, and after round 4 giving best performance for the final)
New brushes every meeting.. serrated ones.
So my motors never lasted a long time.

[Holst]

This was when I was running 27T stock motors, ive never botherd chilling modifieds.

Looking at your link :)
I once beat Dresher at a UK radio race car meeting ... his car broke :P
hehe.

[D_o_S]

I wrote this reply yesterday but the foryum broke as I clicked reply :P

I used to have a can of freeze spray that I used to chill my stock motor before a race. Did give you more punch for the first minute, might also have made brushes last a bit longer as they were not super hot for quite so long.

I would buy some freeze spray (its for diagnosing faults on electrical boards) and test it out before you make a TEC chiller.
If you cant get freeze spray then airbrush propellant gas (i think its butanol) will work pretty good, just turn the can upside down and let the liquid evaporate onto your motor.

You might also want to try com drops that will soften your brushes/com and give you more power. But dont do this on a modified motor, you might kill the com.. stocks tend to cope better with drops.

As for the chiller .. I think it will work a bit, but im not sure how low the temps will get unless you leave it for ages.
A big loud fan will help allot on the heatsink.

How are you going to mount the motor to the chiller?

You really want to be chilling right up untill 30 seconds before the race starts .. thats why I used freeze spray, you can just blast the can with it.

I should point out that when I was racing stocks competitively I would replace the motor after about 4 meetings, or 100 minutes of use.
I would rebuild after every run for cleaning and would skim the com often (usually after round 2, and after round 4 giving best performance for the final)
New brushes every meeting.. serrated ones.
So my motors never lasted a long time.
Thanks for the input.

I was planning on cutting a pipe in half and brazing/soldering it on to the cold plate. My XRay T1FK05 has a wide top deck, so I could maybe lean it against that, or I could just hold it for 30 seconds or so...

I don't really want to keep replacing motors like that though... I want my brushes to last a bit and I don't fancy replacing motors so often.

[Holst]

The reason that I was replacing motors was not the freeze spray, it was just VERY competitive racing. My point being that for club meetings doing stuff like this was pointless, I only bothered with all that stuff for Nationals. As I never kept a motor for very long I never worked out if freezing it did any harm, but I dont think it did.

You would want to leave the chiller on the motor for several minutes before the race to make sure it got down to temperature propperly.
A bit of pipe of the right diamiter soldered to a cold plate would work fine, just clip it to the motor before you race and remove it just before hand.

What class are you racing, 1/10th scale touring?

[D_o_S]

The reason that I was replacing motors was not the freeze spray, it was just VERY competitive racing. My point being that for club meetings doing stuff like this was pointless, I only bothered with all that stuff for Nationals. As I never kept a motor for very long I never worked out if freezing it did any harm, but I dont think it did.

You would want to leave the chiller on the motor for several minutes before the race to make sure it got down to temperature propperly.
A bit of pipe of the right diamiter soldered to a cold plate would work fine, just clip it to the motor before you race and remove it just before hand.

What class are you racing, 1/10th scale touring?

Yep, 1/10 scale touring.

I'm not quite up to that level of competiveness that I'd have to change motors so often, but one never knows, I might be in the same situation one day...

I just thought that this would be an interesting little project... and as MuchMore is selling their "gadget" for around $100 from what I've heard, I'd rather build it myself (no offense to MuchMore though, they do have some excellent products, just this one is a "little" overpriced)

[Holst]

I think your 80watt unit will work much better than there one anyway.

Ive given up racing now, too expensive and I found that I allways drove crap if I went out and drank the night before ... and id rather go out than go racing.

Sometimes still go to the local club and have a mess about, but my kit is all a bit out of date these days.

[ilkkahy]

If coldness gives more power, how about making a light aluminium container for that engine and put some dice there? :D I dont know how much those engines put out heat but they seem kinda small and di sublimating energy is pretty high.

[MaxxxRacer]

D_o_S, I'd just go with a pasive aluminum heatsink on the can. Make sure not to cover up the slots in the can though, want it to get enough air.

If you really want to go crazy, you can take a heat gun and a lexan sheet, molding it so that you suct some air in from the outside. I suggest doing the ducting from the back window. Ducting it from the front will screw up your aeordynamics and forcefeeding it air is a bit over the top i think.

[D_o_S]

Thanks for the replies everyone,

MaxxxRacer, I will look into making an air duct for my motor, it sounds interensing...

I'll also try building the TEC cooler, I'm just a little tight on money ATM...