i need fan help!

well on my cyclone i bought 2 25/25/10 mm fans and i made the mount and all that so theres one fan on each side of the endbell, but what happens is

when i plug in my car (i got rid of the on nd off switch) the fans what all the power, and the spektrum needs the power to boot, so the fans win sortof and

spin slow, and the sspektrum wont boot, but if i pull a wire out (theres no plug thingy around the servo plug pin that plugs into the rx) then let the

spektrum boot and then it makes the signal and all then put the wire back in then the fans go and everything works, but as u can imagine its a pita when ur

tryin to get onto the track for ur heat or main

so sorry for the HUGE rite up, but i need help, how or what can i do if there is anything to make it all work rite when i plug in the batts and thats it?

thx:018:

[Procharged5.0]

Where are the fans wired in?

Have you visited Brian's fan wiring reference diagram?????

It sounds like you're trying to run a mess of fans in parallel off of the aux socket on the radio. I'm assuming that you are running 5v fans. IIRC, these fans combined can pull over an amp and that might be the root of your troubles.

The best way to run fans on a brushless setup is by running them from the lipo pack. If you are running 4S, that is a bit overvoltage for the fans and they might die a bit of an early death. If you are running over 4S, then you'll need a voltage regulator. You can get one from radio shack for about $1. The voltage regulator and do up to 1A and three fans running at 12v won't even come close to the limit.

Check this out...http://www.rc-monster.com/forum/showthread.php?t=5377

[BrianG]

Yup, sounds like you are overworking your 5/6v UBEC. Fans work much like any BL system: they require a certain amount of power to run. So, at lower voltage, they need more current.

If you are using 5v fans, you can put three in series directly on 4s lipo and they will work fine. If you have only two, I would put them in series and use an LM317T adjustable regulator to get 10v. You simply use two resistors to program the regulator to whatever voltage you want. You could use a simple 12v regulator, but that would still be overvolting those 5v fans even in series.

Alternatively, you could another cheaper 5v UBEC to power just the fans. Then use your existing one for the receiver/servo(s).

yes there 5 volt fans, i just took boolth +'s and -'s and crimped them to one lil pin..... theres no lipos lol i race this, 6 cells is the limit on what i can run there, but these ib's are nuts! 60 bucks, but there putting out 1.5 volts a cell!!! thats 9 volts these guys put out, and the difference from my gp3300's is nucking futs! lol

but anyways, any way i can put like a cap or sumthing on the rx? or wire them in somehow so they work? there hooked into the rx, i DONT want to put them on my esc plug as that makes my wireing messy, and i cn just pull the wire if i dont want to run them

[BrianG]

A cap won't help. Your problem is that there is too much constant current drain. A cap will only help with bursts of current draw. If you are using 6 cells, your best bet would be to use a LM7805 regulator for each fan since each fan draws ~1A.

Be warned, 2A (total) of fan current will affect runtime.

Or better yet, design the setup so a fan is not needed at all.

well if i cant get that to wrok like i want it, then i will just do it like i have been

doesnt matter, i cant even use much more then 1000 mah for a few practice laps, and the 5 min heat, so that doesnt matter

and no, the motor runs fine without them, but the cool it runs they longer i can run without a cut and brushes, and they perform better

[BrianG]

What are "brushes"? ;)

there things that go in a motor :D

but really, there isnt any other way huh? i thought there would of, guess i better call up my budy at the track, he was running 2 fans in his jrxs, same with a few pros that have there pics in mags so idk

Oh, when I was talking about the fans, I meant to say that you should get some 12v fans.

Anyway, if you're just running with the nimh pack, you could just run the fans from your pack. They'll be overvolted, but should survive, although they will be sucking some current.

What's your setup? I've been working toward a fan free conversion. I HATE fans.

i have a trinity co27, lrp sr (punch machine) wce ib 4200's, all the numbers on the pack are EXACLY the same! then the moore speed cyclone

and i dont want to run them through the speedo really, they REALLY crank tho when u touch the leads to the batt leads lol

fans are novak btw

[BrianG]

You can put a simple resistor in line with the fan to help drop the voltage so they don't spin quite so fast. About as efficient as a linear regulator. I would need the fan's voltage and current rating though to calculate the proper size.

well thx!

i did the esc wiring, thats what i wanted in the first place but didnt, so i did and got it SOOOOO CLEAN! waay more clean then the servo wires, and works PERFECT!

[rchippie]

Originally Posted by BrianG

Yup, sounds like you are overworking your 5/6v UBEC. Fans work much like any BL system: they require a certain amount of power to run. So, at lower voltage, they need more current.

If you are using 5v fans, you can put three in series directly on 4s lipo and they will work fine. If you have only two, I would put them in series and use an LM317T adjustable regulator to get 10v. You simply use two resistors to program the regulator to whatever voltage you want. You could use a simple 12v regulator, but that would still be overvolting those 5v fans even in series.

Alternatively, you could another cheaper 5v UBEC to power just the fans. Then use your existing one for the receiver/servo(s).

Brian if your running your fans of the battery's why would'nt you just use a 12v fan ?.