Reedy motor fan

Old 04-15-2004, 06:34 AM
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Default Reedy motor fan

Is it safe to hook this up to the bat terminals, as if I use the BEC from the reciever, the fan is really slow??

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Old 04-15-2004, 06:36 AM
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it is probably a 12v fan , if you use a 5v fan it will move much more air.
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Old 04-15-2004, 06:48 AM
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It is a 5V fan, but its only being given like 3.6V from the BEC from the speedo. Do you think I should just hook it up to the 7.2 volts from the bat terminals to give it enough power??

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Old 04-15-2004, 07:51 AM
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What speedo are you using??

3.6V from ESC is not right; most supply 5V, some even 6V.
Your radio would probably call it quits anything less than 4.5V.


That little Reedy fan only gives a gentle breeze, can't expect a
gale-force wind out of that. But its still very effective, surpringly.
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Old 04-15-2004, 07:55 AM
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Yeah, I think it probably is 5V, can't find the manual so can't tell u I'm affraid. It does only supply a very, very small breeze though (probably because I'm not using a FET servo), and also somewhere in the BRCA rules it says you can't use the bat port on the reciever for anything but timing equipment... Basically, do you think I will be ok to run it off 7.2V, or will it burn it out??

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Old 04-15-2004, 08:40 AM
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You'll burn it up at 7.2..

I had a fan with the same specs, and it worked find bench testing even at WOT, but when I came off the track, the fan was HOT, and no longer worked.
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Old 04-15-2004, 08:45 AM
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question?

does the fan help cool down the temp of the motor while running?
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Old 04-15-2004, 08:49 AM
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Electronic components rated at 5V probably would only start
complaining at 2x the rated voltage, so you've usually got some
fat to play with @ 8V (fully charged pack?).


However, we are also talking about BRUSHLESS motors - their
speed isn't directly proportionate to the voltage fed to it.
Double the voltage and the RPM don't double... (but torque does).

(I run 12V 4" brushless fans at both 12V & 7V... the speed isn't
very different either way. But the other day my finger got stuck
into one when it was running off 12V - oww that hurt. Sliced a
chunk out of my fingernail!! At 7V it don't even hurt. )


Dare say your ESC should be feeding it the right voltage eg 5V.



Can't help you on the rules, though... how anal is your techhies?

What if you buy a servolead Y-adaptor, you can stick that on any
of the servo or ESC wires and run the fan off that??

You need it anyway if you need to keep your BATT plug free to
run a AMB PT or Orion lapcounter at the same time.
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Old 04-15-2004, 08:53 AM
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Can you just solder the leads from the fan to the motor?
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Old 04-15-2004, 08:53 AM
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I run a 5 volt fan, and have for a long time. It is not the reedy fan, but I hooked it up to my motor leads. This way it only draws juice when u give the motor throttle. It will not suck ne of that precious battery peak by continuously running off of the battery. TSR6 has seen my setup, I will try and find pictures later.
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Old 04-15-2004, 08:55 AM
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Originally posted by rice
does the fan help cool down the temp of the motor while running?
yes, I was quite surprised how effective it is.

Pal at track started playing with them; usually our stockers come
off hot enough to burn your hand. With the little fan heatsink
(even when I thought it wasn't making much of a breeze)
the motor came off cool enough to touch - amazing.

It does point the airflow towards the Brushes, which is where
most heat is generated. Older styles of fanned motor heatsink
where the fan blows on the heatsink (ala Pentium PC cooler)
aren't as effective.


Other thing to consider is, I'm told... folks in Asia are using
"Air scoops" to tunnel air towards their motor when car is running.
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Old 04-15-2004, 08:55 AM
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Originally posted by rice
question?

does the fan help cool down the temp of the motor while running?
If it's the heatsink/fan combo they're talking about, then yes it does...when it stays on! I had one for my XXX-S and it fell off 3 out of 5 times I got to use it. The 2 times it did manage to stay on, the motor temp was noticeably cooler by touch. No temp gun to confirm, so it may be in my head.

You don't want the fan blowing on the can, you want it blowing on the brush hood and brushes cause that's where all the heat is generated.

So another racer said "You have to bend AE heatsinks to make them fit snug". He proceeded to bend and then snap the heatsink in half
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Old 04-15-2004, 09:02 AM
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This is my car setup from the birds race that I had been using for awhile. And yes it does stay noticeably cooler. I have noticed a drop of up to 40 degrees at one time depending on track size, gearing, and outside temp. Go to this link for the pic.
http://www.rctech.net/events/snowbir.../index20.shtml
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Old 04-15-2004, 09:42 AM
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I would just buy a 5v fan and shoe goo it in. I have done it for almost a year now and love it. I soldered it in with the ESC receiver harness so my batt slot is still open for the AMB counter. I like to use it since its in a TC3 and I use less weight to counter balance the batteries and at the same time have a cooler motor. I will have to get a pick to upload. Pick up the trinity xxxs or tc3 foam stand with fan, the fan in it is the perfect size and specs for this.
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Old 04-15-2004, 10:17 AM
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Thanks guys. I did try it on the bat, but for some reason it slowed down after a while. Whats wrong with that?? Racing tomorrow, so I will know what a difference it has made.

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