Engine Fan Heating up

[sookainian]

After changing my engine washer to 0.5mm ( orginal is 1mm ) Today i tried flying the heli, after flying for awhile, i notice soemthing very weird.

After landing it, i touch my engine fan and notice the fan is hot :?

Anyidea what causing this ?

Or is it normal just that last time i didnt notice about this ?

[DavidH]

Well heat can be transferred from the motor to the fan. The fan acts sort of like a heat sink since it is connected directly to the motor and it is made of aluminum.

Only thing that might cause it to be exceptionally hot is that it is rubbing the end of the crankcase.

Other than that it is normal for the fan to be about the same temp as the engine at times.

David

[sookainian]

ok thanks David, i think i found out the reason, the fan is rubbing against something, when i open it and see, there is alot of golden dust :arggg:

[tnreefguy]

the golden dust is what's left of your engine collet. the fan is probably hot due to it slipping. did you notice any loss of headspeed

[sookainian]

yap, notice alot of power lost and engine screeming. Tighten back, but today at the field same thing happen, it is screwed =(

[Peter]

yep . collet will be stuffed , fan probably will be too ....

[chrisvau]

sookainian,

I belive this has happened becuase you use a .5 mm trhust washer instead of the supplied 1mm one. The top collet would not have been able to press down and seat far enough onto the the flange on the crankshaft becuase of the thinner washer. This means you fan would not have been seated tightly into the brass collets. Make sure you use the 1mm washer instead and sort out any fan to clutch spacing by shimming either engine backplate or frames NOT using a thinner washer.

Regards
Chris

[sookainian]

Ok, i got what u mean guys.

I just learn from the hard way :arggg: