Blower fans
 

Has anybody tried using blower fans instead of radial fans? Seems like for motor cooling, we may have more mounting options when using a squirrel cage stile mini blower fan. These take air from the front and blow it out the side, instead of out the back like a radial fan... so you can mount them flat on the chassis, or up against a body without needing to cut a hole. I'm gonna experiment with these, but surely somebody else has tried. Would love to hear from anybody that has given this a go.

Might be because of the weight and size.

No room on my chassis for that type. Weight and dimension may make it not possible for buggies. Perhaps there is room on late model or pancar chassis?

They are the same size. 30 x 30 x 10 or 7mm. Think the flat fan in your laptop.

I see what your talking about now. Is there one that will work with 7.4 volts? I know they have 12 volt units, but those are quite large and how well will they work at 7.4v. Hook one up and let us all know how it works out.

I'm doing some research so I'm not sure at the moment. I have found a few 3-6V fans, and those should work fine on 7.4v, or 6v if running through the RX. The plan is to mount it on the battery hold down and use a small shroud (made from Lexan scraps) to direct air into the motor instead of around it.

One thing that is a bit misleading is air volume ratings. These micro blowers cant push as much volume as an equally sized axial fan. However, blower fans can maintain far more pressure, so for a solution like this, they should work quite well. Axial fans suffer from bounce back, so when used in a shroud or too close to another surface, efficiency diminishes quite a bit. High CFM sounds attractive, but what good is a high volume of air if most of it never reaches the item you are trying to cool? Seems like we compensate for this with more RPM, but IMO, that's a bit of a band-aid solution. In theory, a shrouded/ducted blower will work better because it will be able to deliver air more efficiently. Not too worried about weight as this should weigh less than those aluminum fans everybody uses.

Only way to know is to try. I'll start a thread when I source the fan and install... should be interesting.


If this works, not sure it will be the best solution for every car, but at least it will give people more options, specially for cars that somewhat have cramped quarters (like the B6.2).

A more common name for this type of fan is Squirrel Cage Fan. Here are some 12 volt models, but would probably give you decent flow at 8 volts:


EDIT: Actually running a 12 volt fan at 8 volts is a bad idea, since power will go down linearly with voltage and fan flow will go down by cube of power ratio. The flow at 8 volts will be 30% of what it would be at 12 volts.

Interesting idea. I suspect the shrouding/ducting will be important, to get cooling over a significant portion of the motor, since radial fans usually have smaller cross section outputs. A concentrated blast may not cool as well as a milder breeze over more of the motor?

Yes, shrouding/ducting will be very important. My goal is to get air into the motor, not just around it.

I just got back into RC cars after spending the last 12 years with helicopters and airplanes, and it's interesting to see how car motors went in a completely different direction when it comes to case design and cooling. Helicopter motors have built in centrifugal fans and a good amount of aluminum to act as a heatsink. Most airplane motors don't have built in fans (for obvious reasons) but still have the extra aluminum to act as a heatsink. Seems like all of the popular 1:10 RC car motors have no fan and a thin and cut-away case that doesn't work well as a heatsink. Great for lightness, not so great for efficient cooling.

It seems like these motors are designed with supplemental cooling as a requirement.

The case on my Reedy S Plus is .7mm thick, and mostly cut away. Almost no heatsink to speak of, but lots of ventilation. It should be fairly easy to force air into this motor.

Don't read too far into this folks, I'm just experimenting because I like to tinker. If this doesn't work well, then it doesn't work well, and I'm out $15-25 and a couple of hours of tinkering. If it does work better than the current solution, then I can squeeze a bit more power out of the motor. Either way, it's a fun project.

I'll be comparing results with a popular OTS fan that I'm gonna pick up at the track tomorrow. I've been running fan-less the past couple of weeks and it's been fine, but once I started playing with boost timing the need for a fan quickly became apparent.

I have been tinkering around with heat pipe technology.. thou at a stand still yet, I imagine someone else is probably been thinking the same thing. It doesn’t have to be made of copper, aluminum tubing works as well.

I've used those fans on one of my bashers. It did seem to push more air then the standard fans, and the temp numbers confirmed it was an improvement. I had bought 4 cheapos from china, ended up breaking 3 on my truck pretty quickly. Broke every plastic fan I've used on it actually. Hopefully you see good results too