Ezrun Fan Problem

[V1nce]

Hello,

The fan which sits on top of my Ezrun 35A ESC bite the dust yesterday afternoon, ruining my evenings racing in the process.

There is no rotation from the fan, not even a kick when the ESC is switched on. The Centre of the fan gets very hot very quickly and rotation by hand feels stiff. There is no other problem with the either the motor or the ESC. Both function as expected, so its just the fan that’s dead.

Fully charged batteries reading at 8.2V powering a fan that the manufacture rates for 5Vdc 0.12A max 7.2V explains the problem. (not to sure whether to worry about that reading from a 7.4v MiHM battery :S) Over powering the fan could also explain why it sounded like a jet engine now and again. So this is my own problem to sort and this is where I need help...

Ok I've brought a similar 25x25x10 fan from 3Racing. However I couldn’t find a tech spec for this fan so I'm guessing it’s going to require an identical voltage and current draw (it’s probably the same fan!). After doing a bit of research I’ve got a few ideas that I’d like some help with...

- Directly replace the Ezrun fan, and then replace this one when it pops in a few weeks. Yup killed the original fan like that, stupid idea... Next!

- Take the positive power for the fan from ESC's receiver power out. The ESC provides the receiver with 6Vdc so why not tap into that. Could this damage my ESC or receiver? It worries me that the manufacture didn’t think of this when they designed the product if it was completely safe.

- Buy a BEC or draw power from my Futaba R603FF's 3rd channel.

- Buy a 12Vdc Fan as recommended in the Ezrun manual for running batteries above 7.2Vdc. Any ideas where to source a suitable 12V replacement in the UK?

What is a most suitable option?

[TA-Mark]

If the fan is tight to spin the bushes in it are choked up. If you race on carpet most likely with carpet fibres.

I pull these fans to bits all the time, they are the same design as a pc fan but much smaller. There is a small plastic c-clip holding the shaft in, pop it off with a pin, and clean the shaft and bush. Relubricate with some ceramic grease and reassemble. It's right to go until the next time it clogs up. Same deal with a pc fan.

Only time you need to replace them is when the bush becomes so worn the fan is wobbling and hitting the casing, or if one of the windings burnout (very rare).

[V1nce]

Yes I race on carpet and it does clog with carpet fiber. I normally clean the fan out every couple of weeks, however I have never dismantled the fan to clean the internals.

Its is a good point so I've just open the fan. It was pretty clean inside, but I gave it a blast with the air duster... A again it failed on test.

[TA-Mark]

Blasting with air compoinds the problem. Just pushes the fibres deeper into the bush. Common misconception with PCs too. Dismantle completely and regrease so it will spin freely and it will work again.