When cooling a motor which way is better?

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Diem Turner said:
To my knowledge the Powerhobby fan mounts are the only ones of this type of clamp fan mounts that can accommodate two fans and not just one. How is it that Powerhobby was the only manufacturer smart (or dumb) enough to put two extra holes in the same mount? Yeah, technically you can sell twice as many if it only mounts one, but I'll go out of my way to get the Powerhobby one just so I can mount two.
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eBay cheapo accommodates 2 fans, 2 40mm or 2 35mm. The included fans are terrible though. https://www.ebay.com/itm/234246128534?hash=item368a284396:g:EgsAAOSwoU5hb~J6
 
kreeg said:
#2 is incorrect. Every application of the heatsink and fan in electronics the fan is blowing air onto the heatsink. Not drawing air from it. For example, look at the fan on any ESC.

Proper heatsink and fan setup
Click to expand...

Well, no..
Actually, if you look at computer case fans (especially Blade Server Chassis) , most of them ARE drawing air From the hot components {and exhausting it out the top or back ,NOT blowing on)
But, it's not written in stone on how the arrangement SHOULD BE but rather what is "best" for the application.

For example, if you have a near Silent PCs ,where you have Only CPU, GPU, RAM Heatsinks in a miniATX case , the one fan usually just Draws air Out and NO fan blows in ,back onto those heatsinks.
.


*************************************

Also, regarding fans for RCs...
Why you see so many of them mounted where's it's facing up and thus blowing down onto the heatsink... is Because the Fan's centerHub+blades+brass bushing (or ball-bearings) are basically "press fit" onto the fan-center-Post ,that overall mass Can/WILL pull itself out during a hard landing IF it was mounted upside down towards gravity.

That's why all RC fans are mounted in "face up" arrangement, to prevent the blades from popping off its frame.
 
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Tex Koder said:
Well, no..
Actually, if you look at computer case fans (especially Blade Server Chassis) , most of them ARE drawing air From the hot components {and exhausting it out the top or back ,NOT blowing on)
But, it's not written in stone on how the arrangement SHOULD BE but rather what is "best" for the application.

For example, if you have a near Silent PCs ,where you have Only CPU, GPU, RAM Heatsinks in a miniATX case , the one fan usually just Draws air Out and NO fan blows in ,back onto those heatsinks.
.


*************************************

Also, regarding fans for RCs...
Why you see so many of them mounted where's it's facing up and thus blowing down onto the heatsink... is Because the Fan's centerHub+blades+brass bushing (or ball-bearings) are basically "press fit" onto the fan-center-Post ,that overall mass Can/WILL pull itself out during a hard landing IF it was mounted upside down towards gravity.

That's why all RC fans are mounted in "face up" arrangement, to prevent the blades from popping off its frame.
Click to expand...
I'll play devil's advocate here: Case fans are designed to control ambient air in the case regardless of orientation. Most cases have exhaust fan mounts AND air intake fan mounts. While the standard PC case comes with atleast one exhaust fans, they frequently include air intake fans on the front creating a push/pull configuration. It all depends on what the needs of the system are and how you need to control air flow. Low power electronics can get away with passive heat convection.

I think you're right that fans should be used for what's best in that specific application. But the important thing is finding the right way to waste heat. If you have a closed off RC chassis (I'm looking at you, mojave with scorched fenders!), even if you blow a fan straight across the heatsink, you'll only be dumping the heat back into the chassis to be recirculated and heated up again. Similarly, if you have good chassis ventilation but only run a fanless smooth can motor, you're likely still going to have heat problems.

Is it safe to say that the most universally beneficial way to reduce temps is a fan blowing directly on the motor/heatsink?
 
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I think in this application it is safe to say that blowing on to the motor or heatsink is the best solution. I prefer motors with fins machined into the can and a bracket to attach a fan or fans to blow air on it at high speed/volume. It is important to ensure your fan is spaced out from the motor far enough to not mess up the air flow by building up pressure. It doesn't have to be far and the fan mounts I am using (cheap BangGood ones) space them out enough that it seems to work really well - judging by my motor temps.
 
Diem Turner said:
Wow, that was a ballsy move. Tip of the hat good sir. And yeah, SA is far more bearable than Houston. Spent a weekend in SA when I got my permanent residency and found some really excellent Tex-Mex on the river walk.

Thompson was a truly unique nutter and his writings are awesome. "One of God's own prototypes. A high-powered mutant of some kind never even considered for mass production. Too weird to live, and too rare to die."

I still need to catch up on some Kerouac. What book of his would you recommend?
Click to expand...
Yup love that line from fear and loathing.
‘On the Road’ is Kerouac’s most known and best introduction to his insane writing style. He wrote it on a 18 foot long assembled single sheet of typing paper over a three week Bynzinine (sp?) trip. However my favorite is Big Sur. But it is post chaos after the sudden success from on the road settled. But to start at the real beginning…

His most balanced book where he was young, less drug/alcohol addled and heavily influenced by Thomas Wolfe (cant go home again) is ‘Town and the City’. Equally as long, interesting and slow at times as ‘can’t go home again’ but still a good read.
 
Again, really good feedback to my OP. This make sense to me more now why my TLR runs the coolest at out all 3S-4S line. I know the rig in question is for my Big Rock BLX.

IF the TLR Typhon had a big body like the other rigs hands down I always go to the GC like or make my own tall 40mm fan not the flat ones. I could not with the low body so I did 1x 40mm on the 2050kv BLX motor and same 40mm on the Max8 ESC. By accident and no planning on my part the motor is spaced off by the Powerhobby mount & ESC mount. The ESC has Alza custom fan mount that cut around the compacitors. I kill this one on 4S bashing and temps stay so low. Never understood tech why this rig ran lower off ESC power over the BR GC 40mm powered fan. I get it now.

Thx again for the good feedback hope this one helps others as it did for me!

TLR
1654206537896.png


Motor temp is in blue after two 4S bashes. Red is the ESC. Compare that temp to the 3S powered GC 40mm lipo fan in post #1 this little fan off the ESC is doing great!
1654206762754.png



L3phturn said:
I think in this application it is safe to say that blowing on to the motor or heatsink is the best solution. I prefer motors with fins machined into the can and a bracket to attach a fan or fans to blow air on it at high speed/volume. It is important to ensure your fan is spaced out from the motor far enough to not mess up the air flow by building up pressure. It doesn't have to be far and the fan mounts I am using (cheap BangGood ones) space them out enough that it seems to work really well - judging by my motor temps.
Click to expand...
Thx Sir...
 
Velodromed said:
Yup love that line from fear and loathing.
‘On the Road’ is Kerouac’s most known and best introduction to his insane writing style. He wrote it on a 18 foot long assembled single sheet of typing paper over a three week Bynzinine (sp?) trip. However my favorite is Big Sur. But it is post chaos after the sudden success from on the road settled. But to start at the real beginning…

His most balanced book where he was young, less drug/alcohol addled and heavily influenced by Thomas Wolfe (cant go home again) is ‘Town and the City’. Equally as long, interesting and slow at times as ‘can’t go home again’ but still a good read.
Click to expand...
Awesome, thanks man (y)
 
parcou said:
Again, really good feedback to my OP. This make sense to me more now why my TLR runs the coolest at out all 3S-4S line. I know the rig in question is for my Big Rock BLX.

IF the TLR Typhon had a big body like the other rigs hands down I always go to the GC like or make my own tall 40mm fan not the flat ones. I could not with the low body so I did 1x 40mm on the 2050kv BLX motor and same 40mm on the Max8 ESC. By accident and no planning on my part the motor is spaced off by the Powerhobby mount & ESC mount. The ESC has Alza custom fan mount that cut around the compacitors. I kill this one on 4S bashing and temps stay so low. Never understood tech why this rig ran lower off ESC power over the BR GC 40mm powered fan. I get it now.

Thx again for the good feedback hope this one helps others as it did for me!

TLR
View attachment 221175

Motor temp is in blue after two 4S bashes. Red is the ESC. Compare that temp to the 3S powered GC 40mm lipo fan in post #1 this little fan off the ESC is doing great!
View attachment 221177



Thx Sir...
Click to expand...
That temperature display is AWESOME. Can you please show me what you are running for sensors and to display that? Is the reading near real-time or will it stick at the highest reading?
 
Tex Koder said:
Well, no..
Actually, if you look at computer case fans (especially Blade Server Chassis) , most of them ARE drawing air From the hot components {and exhausting it out the top or back ,NOT blowing on)
But, it's not written in stone on how the arrangement SHOULD BE but rather what is "best" for the application.
Click to expand...

No, they aren't. A typical blade chassis has intake and exhaust fans, fans which draw cool air in from the front by pulling it through the front of the case, and fans that push hot air out of the rear of the case. CPUs and GPUs are cooled either statically with a massive heatsink which dissipates heat into the atmosphere, or most commonly with a fan blowing air THROUGH it. Some vertical heatsinks will have a push/pull configuration, but very few only have fans pulling air through, and the ones that do are configured in a way that the heatsink is receiving cool air from an intake fan pulling in air at the front of the case and pushing it through the heatsink. Doing so greatly impedes the ability for a fan to create airflow, and it's simply not how heatsinks are designed to work. It's really not even open for debate or interpretation. Look at the radiator in a car. Yes, the fan pulls air through the radiator in most configurations, but that's because your radiator gets fresh, cool air flowing through it when you're driving, which is why the electric fans in modern cars typically only run at idle or when ambient temperatures are very high. This is why if you block off the front of the radiator, it will cause your car to overheat. All of that isn't to say that a fan pulling air through a heatsink can never work, but it's not the best, or correct, way to set it up. You ALWAYS want air being PUSHED through a heatsink to achieve maximum cooling efficiency...it's basically a universal truth.
 
grihn said:
No, they aren't. A typical blade chassis has intake and exhaust fans, fans which draw cool air in from the front by pulling it through the front of the case, and fans that push hot air out of the rear of the case. CPUs and GPUs are cooled either statically with a massive heatsink which dissipates heat into the atmosphere, or most commonly with a fan blowing air THROUGH it. Some vertical heatsinks will have a push/pull configuration, but very few only have fans pulling air through, and the ones that do are configured in a way that the heatsink is receiving cool air from an intake fan pulling in air at the front of the case and pushing it through the heatsink. Doing so greatly impedes the ability for a fan to create airflow, and it's simply not how heatsinks are designed to work. It's really not even open for debate or interpretation. Look at the radiator in a car. Yes, the fan pulls air through the radiator in most configurations, but that's because your radiator gets fresh, cool air flowing through it when you're driving, which is why the electric fans in modern cars typically only run at idle or when ambient temperatures are very high. This is why if you block off the front of the radiator, it will cause your car to overheat. All of that isn't to say that a fan pulling air through a heatsink can never work, but it's not the best, or correct, way to set it up. You ALWAYS want air being PUSHED through a heatsink to achieve maximum cooling efficiency...it's basically a universal truth.
Click to expand...

I'm not sure about that universal truth.. If that's the case then take a look at any residential or commercial HVAC, the condensers are ALWAYS Pulling/Expelling the heat out through the top (or side) of the unit and Never blowing/pushing air at or down the heatsink/coil-fins..
 
L3phturn said:
That temperature display is AWESOME. Can you please show me what you are running for sensors and to display that? Is the reading near real-time or will it stick at the highest reading?
Click to expand...

Thank you!

It reads real-time. I am using two different ones. With ESC like the Firma, I can see the temp on my DX5C so all I need is a motor. I used this here

For rigs that have no Spektrum stuff I need to read the ESC and Motor I purchase this here

I got this idea from JayTee off one of his videos so not mine. Works really good for me just came back in bashing 4 rigs. Temp was 85F today.

I cut the ends off those and added a JST connector to it to power off my receiver. I do still take a heat gun just to see how well they do and guys told me I will be about 10deg +/- off and so far correct. I add 10deg more to the readings. As long as I can keep the motor below 170F and ESC 150F I am happy. We know it can take more heat but this is my goal along with better electronics for less heat.

TLR Typhon today see about 10deg off motor temp is in blue... the gun is showing a motor temp. I was at 19T @4S this test today was at 21T pinion
1654313297113.png


Max on the TLR at the end of day 2x runs on 4S, 10min rest between runs. Last was on a 3S I never run this rig on 3S (first time) only for 4S but on 3S neither temp got over 115F. All runs fun thottle 10min back/forth bashing, no pic for the 3S temps:
1654313659559.png





Losi DB Pro motor in blue and gun reading
1654313366928.png


End of the Losi run 3x 3S batteries I ran it full throttle and only got 10min out each 6200mah battery with a 10min rest between runs I ended the Losi day like this:
1654313482568.png
1654313493990.png



Last bash tonight was the Infraction. Again, full-throttle non-stop drift, straight run into a drift, etc, only 8min...no Hoon tires left. Running it as 6S with the stock motor but a Firma 160A ESC. I upped the opinion on this run to 19T was 18T. 19T got a little warmer but I can live with it. I will not get the 20T which I was aiming for bashing which is all I do. Motor temp blurred no good pic was at 169F for the Infraction.
1654313891504.png
 
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grihn said:
No, they aren't. A typical blade chassis has intake and exhaust fans, fans which draw cool air in from the front by pulling it through the front of the case, and fans that push hot air out of the rear of the case. CPUs and GPUs are cooled either statically with a massive heatsink which dissipates heat into the atmosphere, or most commonly with a fan blowing air THROUGH it. Some vertical heatsinks will have a push/pull configuration, but very few only have fans pulling air through, and the ones that do are configured in a way that the heatsink is receiving cool air from an intake fan pulling in air at the front of the case and pushing it through the heatsink. Doing so greatly impedes the ability for a fan to create airflow, and it's simply not how heatsinks are designed to work. It's really not even open for debate or interpretation. Look at the radiator in a car. Yes, the fan pulls air through the radiator in most configurations, but that's because your radiator gets fresh, cool air flowing through it when you're driving, which is why the electric fans in modern cars typically only run at idle or when ambient temperatures are very high. This is why if you block off the front of the radiator, it will cause your car to overheat. All of that isn't to say that a fan pulling air through a heatsink can never work, but it's not the best, or correct, way to set it up. You ALWAYS want air being PUSHED through a heatsink to achieve maximum cooling efficiency...it's basically a universal truth.
Click to expand...
When I built PC's, server towers or any size, I learned that you want a positive pressure within the PC case. Sightly more positive intake CFM's versus exhaust CFM's. With No internal Case Vacuum. (negative pressure) Carefully selecting/sourcing the Fans' CFM's specs for exhaust and intake orientation.
Best cooling effect. How high end OE PC makers do it.
 
One reason to want positive case pressure in a PC is to keep dust accumulation down. Negative pressure will draw in dust through every opening in the case and you must have good filters and tight junctures to avoid the need to blow the case out frequently.
 
Hector_Fisher said:
I'll play devil's advocate here: Case fans are designed to control ambient air in the case regardless of orientation. Most cases have exhaust fan mounts AND air intake fan mounts. While the standard PC case comes with atleast one exhaust fans, they frequently include air intake fans on the front creating a push/pull configuration. It all depends on what the needs of the system are and how you need to control air flow. Low power electronics can get away with passive heat convection.

I think you're right that fans should be used for what's best in that specific application. But the important thing is finding the right way to waste heat. If you have a closed off RC chassis (I'm looking at you, mojave with scorched fenders!), even if you blow a fan straight across the heatsink, you'll only be dumping the heat back into the chassis to be recirculated and heated up again. Similarly, if you have good chassis ventilation but only run a fanless smooth can motor, you're likely still going to have heat problems.

Is it safe to say that the most universally beneficial way to reduce temps is a fan blowing directly on the motor/heatsink?
Click to expand...
PC's sit stationary in one location during operation. RC cars put fans through very hard abuse. Gforces/impacts destroy these RC fans, which are technically just repurposed PC fans in reality. Fans that were actually designed for the Northbridge, GPU's and CPUs of a PC Main board.
Two different enivronments.
Alloy fan cages are proven to be better for this reason. An RC driven concept.
 
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TimePancake said:
Cooling is 2 things

1. Surface area. So a large heat sink with multiple fins, to create this surface area.

2. Air flow to remove heat through the heat sink. Contrary to popular belief you want the fan to blow air up off the motor not on to it. This will draw the heat away. The air flow will draw cool air back over the heat sink to help continue the cooling cycle 👍
Click to expand...
I couple weeks ago I looking for fans and was curious and researching exactly what you said about which way to have to fan blow. Everyone told me you wanted it to blow on the motor not suck away from it. The comment that stuck with me the most from the whole ordeal was- “When you are hot do you stand in front of the fan and have it blow cool air on you or behind it to let it suck the warm air off you?” Question answered and the end of the conversation for me! Lol
 
 
yes best stone guard i ever had on a fan and my motor stays stone cold since i started using this bad boy!
 
I told you it was contrary to popular belief, but it's no good blowing hot air either if its hot no where to go 😂 I was purely commenting on flow.

Still, got the conversation going, didn't it 😉
 
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