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-   -   Motor cooling - best fan positioning ? (https://www.rctech.net/forum/radio-electronics/709311-motor-cooling-best-fan-positioning.html)

Pygmy 03-01-2013 04:02 AM

Motor cooling - best fan positioning ?
 
For cooling a 550 motor, hypothetically if there are no restrictions to where the fan can be placed, what would be the optimal fan positioning to create maximum cooling ?

On the side ? From the back ? Angled ?

crazy nick 03-01-2013 04:29 AM


Originally Posted by Pygmy (Post 11877029)
For cooling a 550 motor, hypothetically if there are no restrictions to where the fan can be placed, what would be the optimal fan positioning to create maximum cooling ?

On the side ? From the back ? Angled ?

If you are mounting a fan, just keep in mind you want it to b vertical on an offroad vehicle. Reason being when u land off jumps you will not b putting stress on the fan blades. If the fan is laid down horizontally you will be breaking fan blades off. It happens often on esc's w/ horizontal fans. Aslo you want to pull air away from the motor not blow air at it. You will just b blowing dust and grime at it, just some things to think about.

Pygmy 03-01-2013 04:41 AM


Originally Posted by crazy nick (Post 11877081)
If you are mounting a fan, just keep in mind you want it to b vertical on an offroad vehicle. Reason being when u land off jumps you will not b putting stress on the fan blades. If the fan is laid down horizontally you will be breaking fan blades off. It happens often on esc's w/ horizontal fans. Aslo you want to pull air away from the motor not blow air at it. You will just b blowing dust and grime at it, just some things to think about.

Thanks!
Pulling seems much less efficient than pushing though. If I burn myself with my soldering iron, I'll blow at the burn, sucking air around it just doesn't seem to work that well :)

Bigwave 03-01-2013 09:14 AM

If geared properly you shouldn't really need a fan at all to be honest.

pablo040 03-01-2013 10:08 AM


Originally Posted by Bigwave (Post 11878051)
If geared properly you shouldn't really need a fan at all to be honest.

+1 :nod:

Fans aren't supposed to be used to solve cooling issues.

Pygmy 03-01-2013 06:06 PM


Originally Posted by Bigwave (Post 11878051)
If geared properly you shouldn't really need a fan at all to be honest.

You're saying "If your rig is pulling too much power, you need an easier course/slower competitors".
Sorry, but my race is probably quite different from yours. Not everyone's racing in california, or the US of A for that matter.
I was running at 2 degrees(C), no binding anywhere, in a deep dirt track, and my SCTE was overheating my 3656SD / SCT Pro every time around the end of my laps.

So I spent some time, ordered some high rpm chinese 30x30x15 fans to replace the stock Hobbywing fan, and it works - my ESC isn't overheating anymore.
Now I have 2 fans left, and I like to know how to position them best to cool my motor.
Preferably by people who know how to direct airflow in an SCTE.

mkiiina 03-01-2013 06:33 PM

You are right, however I can run my scte with an RX8/4600kv motor in the dead of summer in TX and NOT overheat.

A fan is a bandaid or a way to increase the longevity of a component (esc or motor) but it should not be an excuse to incorrectly gear your car. With the motors we have now and the escs we have power is never a problem, too much power and speed are.


Originally Posted by Pygmy (Post 11879765)
You're saying "If your rig is pulling too much power, you need an easier course/slower competitors".
Sorry, but my race is probably quite different from yours. Not everyone's racing in california, or the US of A for that matter.
I was running at 2 degrees(C), no binding anywhere, in a deep dirt track, and my SCTE was overheating my 3656SD / SCT Pro every time around the end of my laps.

So I spent some time, ordered some high rpm chinese 30x30x15 fans to replace the stock Hobbywing fan, and it works - my ESC isn't overheating anymore.
Now I have 2 fans left, and I like to know how to position them best to cool my motor.
Preferably by people who know how to direct airflow in an SCTE.


narcotiks 03-02-2013 02:29 AM

So to answer your question, the best place is basically anywhere where you can get allot of air blowing onto the motor. On my tc I mount the fans on the chassis. You can do the same just use 2 or 3 pieces of double sided tape one on top of the other so there is something that can absorb the inpact from bumps and not break fan fins, and I agree with you that the fan should be blowing air onto the motor, 550 motors are usually sealed cans because the manufactures know that they will be used in off road applications, therefore, no dirt will be blowed into the motor. Sucking air off the motor is an extremely less efficent method that isn't really doing anythibg. Also make sure that you plug the fan in to your chosen power source in your car and start with the fan right up against the motor, move it away from the motor until the sound pitch changes and stays the same, mark this position and then mount your fan there, this ensures your using the full potential of the fan.

fq06 03-02-2013 07:25 PM

Another thing to think about if you are having heat issues in your motor.

If you gear it to hit 160° max with the fan and your fan craps out 1 minute into your run you will be hitting a lot higher temperature than you want your motor to see.

As said, gear to the correct temp without a fan. The right way to do it.

You said 550 motor but then you said HW 3656. Which motor is it? If its the HW 540 four pole... that motor rips and runs cooler than most. 120° no timing or 145° with about 25° esc timing. If your over heating in 2°C there's another problem assuming normal gearing for your scte. Replaced bearings recently? You said no binding but somethings gotta be wrong.

pablo040 03-02-2013 08:31 PM


Originally Posted by Pygmy (Post 11879765)
You're saying "If your rig is pulling too much power, you need an easier course/slower competitors".
Sorry, but my race is probably quite different from yours. Not everyone's racing in california, or the US of A for that matter.
I was running at 2 degrees(C), no binding anywhere, in a deep dirt track, and my SCTE was overheating my 3656SD / SCT Pro every time around the end of my laps.
:
So I spent some time, ordered some high rpm chinese 30x30x15 fans to replace the stock Hobbywing fan, and it works - my ESC isn't overheating anymore.
Now I have 2 fans left, and I like to know how to position them best to cool my motor.
Preferably by people who know how to direct airflow in an SCTE.

:weird:


Originally Posted by mkiiina (Post 11879864)
You are right, however I can run my scte with an RX8/4600:rolleyes:kv motor in the dead of summer in TX and NOT overheat.

A fan is a bandaid or a way to increase the longevity of a component (esc or motor) but it should not be an excuse to incorrectly gear your car. With the motors we have now and the escs we have power is never a problem, too much power and speed are.

Yup! :nod:

It's not just the outside of your motor that's overheating, because that's all you're really affecting with the fans. So while you may be cooling off the outside ofthe motor you're still overheating the core.


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