Finnaly! My E-revo Is Really, Really Complete!!!! - Page 2 - RC-Monster Forums

mmdooley · 08:26 PM

I think it looks great! I have been thinking about this for awhile, Tell me what you think. Would the motor and ESC be cooler if the fans were set to "pull" air away from the motor and ESC? Instead of blowing air over them? I worked in a factory with alot of electrical systems and no air conditioning. And they (maintenance) always pulled air away instead of blowing air over electric components. Just a thought :D

P.S. You know a RC project is never really over. lol :L:

BrianG · 08:23 PM

nbcaznmaster, your Revo looks worlds better without the cardboard. :cool: Aside from the gearing, the added weight from the Al vs cardboard may also have something to do with no wheelies though.

Speaking of gearing; given a gear ratio, what is the advantage of using a larger spur/pinion vs smaller spur/pinion? I mean instead of using 70/19, why not 51/13 (or 14)? The ratio is [about] the same. The only advantage I could think of using larger spur/pinion would be the fact that more teeth are in contact at any one point due to the decreased curvature at the point of spur/pinion contact.

nbcaznmaster · 12.10.2005, 08:24 PM

well, they the only spur/pinions i got right now. i got 70t, and 72t 15, 17, 19 fo rpinions.

BrianG · 08:30 PM

Quote:

Originally posted by mmdooley
I think it looks great! I have been thinking about this for awhile, Tell me what you think. Would the motor and ESC be cooler if the fans were set to "pull" air away from the motor and ESC? Instead of blowing air over them? I worked in a factory with alot of electrical systems and no air conditioning. And they (maintenance) always pulled air away instead of blowing air over electric components. Just a thought :D

To pull air, you have to make sure the device to cool is in the air flow. Since there is no air duct directing air directly over the motor/ESC, some air would sneak in right at the fan instead of over the motor/ESC. In this case blowing is better than sucking (please, no funny comments! :)).

In electrical/computer systems, the exhaust fan pulls air through the whole case so it has to go over all the components to cool. shoving air into a case does cool too, but the air tends to just swirl around without a direct path of flow reducing its effectiveness.

BrianG · 12.10.2005, 08:30 PM

Quote:

Originally posted by nbcaznmaster
well, they the only spur/pinions i got right now. i got 70t, and 72t 15, 17, 19 fo rpinions.

That makes sense I guess! So aside from personal inventory, are there any advantages of larger gears vs smaller gears as long as the same ratio is maintained?

nbcaznmaster · 12.10.2005, 08:34 PM

wait, so i should make the fans blow out? or blow ON the stuff? cuz i have them blowign ON.

BrianG · 12.10.2005, 08:36 PM

Quote:

Originally posted by nbcaznmaster
wait, so i should make the fans blow out? or blow ON the stuff? cuz i have them blowign ON.

Yes, blowing "on".

nbcaznmaster · 12.10.2005, 08:38 PM

hmm, wut if u put in fans ON the body? lol, built in fans on a body would bee petty cool.

BrianG · 12.10.2005, 09:01 PM

Maybe if the body was a bit sturdier and the airflow would pass directly over the motor/ESC. However, the fans would then be too exposed to dirt/snow/etc.

Personally, I don't like using fans, they just add more weight, wiring complexity (however small), and something else to break. I'd rather use bigger heatsinks whenever possible.

mmdooley · 12.10.2005, 09:07 PM

What if you have a heat sink? It pulls heat away from the motor an esc?? :)

Sylvester · 12.10.2005, 09:29 PM

It doesnt "pull" heat away, it dissapates it , how in the world are you gonna find a heatsink for your esc?:)

nbcaznmaster · 12.10.2005, 09:32 PM

a heat sink woudl be heaveier then a fan

coolhandcountry · 12.10.2005, 09:41 PM

If you have the proper set up you should not need a fan. there for you would have less weight to.

BrianG · 09:53 PM

When I say "pull", I mean pulling air - which results in heat being drawn with it.

I have a bunch of heatsinks from past electronics/computer projects. Fashioning a heatsink for the ESC wouldn't be hard at all - maintaining the warranty on the ESC after fitting on a custom heatsink would be. :) Even so, I might attempt to affix a larger heatsink to my ESC (when I get one) anyway.

Speaking of heatsinks, does anyone use thermal compound between the motor heatsink and the motor? Something like Arctic Silver or even cheapie RadioShack stuff.

Oh, and nbcaznmaster, yeah a larger heatsink would add weight, but as much as a regular heatsink, fan, and associated wiring? ;)

nbcaznmaster · 12.10.2005, 10:06 PM

well, waver! im too cheap, i use wut i got! well, i know if i setit up properly i shouulndt need it. I don thtink i need a fna right now at all. But its better to have TOO cold of a system, rather then a hot oen.