Stuck Servos and wiggle in the Swash

[underdroogles]

Hello everyone! This is my first heli and I"m doing my best to figure out all of the ins- and outs of keeping this thing in the air!
I've had quite a few crashes, some pretty bad, and now I can barely keep it in the air it's so unstable. I've been going over all of the different troubleshooting options and I still can't quite figure it out.

Here's my problem:
Very unstable hover- it will shoot up and down randomly and is very difficult to control with the cyclic.
I've pushed the main gear in and that doesn't seem to be the problem. I noticed that there's some play, like 1 mm or so in the blades where if it's off I can wiggle the blades and change the pitch with my fingers. The swashplate moves a bit when I do this. I'm not sure if that's normal or not.

Secondly- The sevros scream sometimes when adjusting, and one of them in particular seems to get stuck and lag behind the others. I just took them off and cleaned them, but they still scream and still lags behind. I attached a video if that helps:

Stuck servo on Blade MCPX BL (0 min 16 sec)

I really appreciate any help you guys can offer. I've tried everything I can think of to get it back to stable flight, but nothing seems to help.

Thanks again!

[HeliLust]

What did you use to clean them with? when I first cleaned mine I only had alcohol and it made them a bit better, but not much. Got the deoxid cleaner and cleaned them again and the difference was night and day better.

Also if there screaming the motor and mechanics probably need to be replaced. It's not an easy task unless you are skilled with soldering and have the right stuff to do it. On a brighter note though you usually can pick up new servos off eBay for $8 ea. The mechanism itself is usually $8 as well, so it's a great deal.

[HeliLust]

I was also going to add from you video it would appear that the pinion gear on the servo motor maybe slipping and or the motor is toasted.

[underdroogles]

Thank you guys for your responses!



I noticed that I can stop the screaming temporarily by pushing up on the pinion gear with my finger, but it hasn't seemed to help in flight. That sounds the easiest to fix, what's the best way to keep it up?

I have done some soldering before, so that seems like the next step after working on the pinion gear.

Any word on the wiggling the blades? Is that normal? Is there something wrong with my swashplate ?

Thanks for your help.

[Wrencher62]

+1 on the Deoxit for the servos. I give mine a shot after every flying session and I take them apart for a thorough cleaning about every 50 flights.

As for the blade wiggle I know mine had a fair bit of slop in the head when it was all stock. I broke the stock swashplate pretty early on when I first got it so I replaced it with a RKH metal swash. The new swash came with rubber O-rings for the ball links and that helped some but it still had a bit of slop. Eventually I bought a Lynx DFC head and the difference was night and day. There is NO slop now and it flies great.

I don't know if that's the same problem you're trying to address but I hope it helps.

[HeliLust]

Maybe try to push the pinion up on the shaft a bit, that may help. Also check the motors end cap and make sure it hasn't separated a bit.

[Imzzaudae]

Remove the servo from the helicopter.

Blade mCPx Linear Servo Cleaning (8 min 29 sec)

Without looking at the servo first hand it's pretty hard to tell but he screaming sounds like a dry bushing on the servo drive motor. A drop of light silicone would not hurt it.

Take a close look at the servo gears for damaged teeth. Use at least a 10 power glass so you can see. There may be a bent tooth or a small peace of grit in the teeth you cannot see without the glass. Pinion may be stripped.
You can buy servo gear sets.

I'd check the feathering shaft while your servicing the helicopter.

mCPX Shakes & Servo Cleaning - indoorHELLi 005 (9 min 33 sec)

[underdroogles]

Thanks everyone for the suggestions. I'm thinking that the one servo is fried or the pinion is slipping.THe gear is able to move up and down slightly on the shaft, and that servo lags far behind the other ones or doesn't move at all.

Before I replace the servo, is there a way I can try to fix the pinion gear if that's the problem? Some glue on the shaft or something?

[underdroogles]

Also, do they sell new servo gears? I can't seem to find any online. Just a replacement servo for 8 bucks or so. Any suggestions?

[HeliLust]

The best bet is just getting the $8 ones off flea bay. You can get the gears and motor by themselves but it's still about $8.

[zzyzx]

I had a similar problem caused by the swash binding on the main shaft. Check the linkage for smooth operation before condemning the servo.