How do you know what part is bad? - RC Groups
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Aug 09, 2012, 10:38 PM
Registered User

How do you know what part is bad?

I need to get my Mini CP back in the air and I'm not quite sure what component(s) are causing my issue. The Mini started having short flight times so I bought a couple new batteries but they didn't make any improvement. Now it doesn't have enough power to get off the ground more than a few inches.

I suspect the main motor is probably to blame but I have also noticed there is some vibration. The blades appear to be tracking fine. I'm suspecting probably replace the motor and check the blades and some of the other components such as the feathering shaft.

All this got me to thinking... what about bearings? How do you know when to replace any of those? When do you lubricate them?

I would appreciate any sage advice to help me get back in the air without having to replace half of the heli

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Aug 09, 2012, 11:12 PM
Cranky old fart
Balr14's Avatar
Your first course of action is to check your battery voltage before and after each flight attempt. Otherwise, you are just taking wild guesses.
Aug 10, 2012, 02:35 AM
Fan of just about anything RC
SoloProFan's Avatar
Assuming the new batteries are ok, and not maltreated, or drained too far, which can wreck a lipo in a single flight, I would say it's either the motor, or a connection somewhere, causing high resistance, and as a result more voltage drop.
Aug 10, 2012, 10:42 AM
Cranky old fart
Balr14's Avatar
I have had several bad chargers with Walkera micro helis that cooked the batteries after a few charges. That's why I always check the voltage.
Aug 10, 2012, 11:32 AM
You really need to do a visual check of your pitch curve first. It is possible that you just do not have enough positive pitch to take off. Is the collar pressed down firmly?
Aug 13, 2012, 08:39 PM
Registered User

The madness continues...

So I have been trying to sort all this out and found a few things, but I'm still not quite off the ground yet.

First, I checked the blade pitch and found it was off. Turns out the main gear had moved on the main shaft. Next I got a couple other new batteries and used a different charger. ...things got a little better. I think I'm on the right track and should be able to get most issues fixed by trimming and replacing suspect parts.

The only issue I'm not sure about is the tail spin. It's an issue I have had since I got the Mini. To keep it from spinning wildly I have to turn up the subtrim to R 36.5 but as you change the throttle it doesn't hold the heading. I have checked the settings and can't figure it out. It's like having tail blowout. If you have ever flown with a cracked tail blade you understand what I mean.

Any ideas what might be happening?

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