HELP - Motor suddenly speeds up

[JFonseca]

Hi,

I can not use my litle 250 heli because it suddenly speeds up witout any warning.

I have a Align RCE-BL15X ESC with a Hacker B20-31S motor in my HK 250 GT. I have tried to program the ESC in the Low and Mid timing setting, but I keep having this problem.

Does anyone have a clue how to solve this problem? Sometime ago a shorted the Castle Creations ESC that was controling this motor. The ESC is burned. That's why I had to buy this new ESC. Do you think the motor was also afected?

What should I do? I'm tired of having this great heli grounded!!!

Thanks for your help,

JFonseca

[cjcj1949]

Can you describe this speed up. Does it initialize ok with beeps? Exactly what happens next? You could try looking at the output from the throttle channel by connecting it to a servo, either on its own or with a Y lead to see if the problem is a faulty input to the esc or a fault in the esc. You might have damaged the rx or you could have a tx with a faulty pot. I don't think you could anything to the motor to cause this fault unless it is catching.

[JFonseca]

Hi,

The ESC initializes ok.

I was still in the flytest phase, but with this little helis I do first a running test grabbing the heli with my hand. The throttle curve is 0, 50,70,70,70. After it reaches the steady speed, at 70%, it keeps that speed for 5 or 10 seconds and then speed up like crazy and I have to go back to 0. It also seems that this proccess can be triggered by rudder inputs, but I'm not sure of that.

Connecting the throttle channel to a servo is a good idea! I'll try that and will let you know the results.

Thanks,
J Fonseca

[cjcj1949]

My DX6i caused my CX2 to take off because of a tx fault. What tx do you have?

[JFonseca]

I have a Futaba FF9, that works fine with the other helis. The Rx is a Schulze alpha-8.35w with some years but almost unused.

The ESC is in soft start and governor mode.

I'm going to test:
- Connect a servo to the throttle channel
- Disable the governor

[cjcj1949]

The standard thing to do is to try and split the system up into separate parts. The quickest way is to do a binary chop. It's like the high low game for guessing a number between say 0 and 1023. You start in the middle 512 and ask if its higher or lower, then if lower you go for half of the half you know its in, 256 if lower and so on. You can then find the number in 10 goes rather than 512 by random. The closest you can get with helis is to work on modules. It's handy to have a cheap esc as a substitute. It doesn't have to be able to drive the motor at full speed so long as you keep the speed low.

I don't suppose it's as simple as the mesh of the motor gear and main drive gear or teeth missing on either?