My brushless MCPx thinks it's a dolphin!

[jamesandyori]

Really!

Ok here is the skinny. Recently my MCPx has developed a porpoising action. It's a slight up and down movement at the nose. It's not constant and will calm down in a hover.

Here is my heli's breakdown!

MH 3 bearing CF frame
extended solid boom with cat 5 wire soldered directly to the board from a 120 motor
plantraco turbo prop
brushless system with a HP05 s motor and 7m speed control
MH swash
Rakon boom support
MH hub
fresh clean servos
new main gear
new MH solid shaft
V-1 board
I use Hyperion 550 mAh batteries with stock plug installed.

I use the stock plug on this heli. The deans seems too bulky for me.

What I've done is:
Replace the feathering shaft, main shaft, main gear, cleaned servos.

So here we are, with my very own flying dolphin.

Any ideas? Could the stock plug be causing the problem? Is it allowing enough energy through to the system?

thanks,
James

[nhoj_yelbom]

check your plug wires under the heatshrink. i had a problem with my neg wire only had two strands still soldered.

[Nytflyer]

What main blades are you using? I find the stock high perf main blades make my BL helis porpoise. The bullets are better but still get a little dolphin action here and there. The kbdd main blades have pretty much eliminated it all together.

[jamesandyori]

I didn't physically check under the hood, but I tried 2 different plugs. Could both be frayed?

As for the blades I tried KBDD blue, white and the high performance blades and bullet blades.

James

[craig303uk]

KBBD's and try to get rid of any play in the feathering shaft / blade grips helped with my dolphing problem, with the stock non bullets on it would go mental unless u give enough pitch to pull through it in FFF.

was better when i ground down the feathering shaft a little.

[dr dremel]

Porpoising on my c05 bird came from play between main shaft and bearings. I sanded down the cf rod I bought for replacing a cracked shaft just a little to much. After replacing it with a correctly fitting one the porpoising was gone.

[jamesandyori]

Originally Posted by dr dremel

Porpoising on my c05 bird came from play between main shaft and bearings. I sanded down the cf rod I bought for replacing a cracked shaft just a little to much. After replacing it with a correctly fitting one the porpoising was gone.

Hummmmm I could pop them out and clean them! I have a ultrasonic cleaner that cleans jewelery and such.

[dr dremel]

Sorry if I wasn´t accurate enough, but my bearings were ok. The play came from my home made main shaft, which I sanded down to much.

Bearings are worth checking, though. Even if I doubt that cleaning will remove any play, cleaning and relubing goes a long way for smooth operation.

Cheers
Dr Dremel

[profilefan]

Do you have the o rings on all of your swash balls? That solved my porpoise effect by placing the red orings on the upper swash balls. Forgot who was selling them here.

[jamesandyori]

It has V-2 mechanics, so it has the black o-rings from Blade.

James

[jabu32]

mine also does this in FFF. not sure what it is caused from but doesnt really effect anything. curious to see what you find the cause is.

[profilefan]

Originally Posted by jamesandyori

It has V-2 mechanics, so it has the black o-rings from Blade.

James

James, that is not good enough. Read this thread,
https://www.helifreak.com/showthread...ghlight=orings

Like I said, when I added those small red orings on my upper swash balls the porpoise effect went away. Perhaps this may solve your problem.

Good luck!

[craig303uk]

doubt o ring's will solve the problem i have o rings all over my heli and i can still make porpoise if i want.

[profilefan]

Originally Posted by craig303uk

doubt o ring's will solve the problem i have o rings all over my heli and i can still make porpoise if i want.

Well they solved my porpoise problem and I believe others as well. Another thing to consider is your tailboom length, i believe that can attribute to the porpoise problem.

You can buy complete sets of those orings from members here for a couple of bucks, why not give it a try.

[motoracer5]

For me it was play in the feathering shaft. I filed it down and used the stiff o-rings for dampers. The Xtreme hub is tighter if you get tired of grinding feathering shafts. The AEO pitch links also fit very snug, I do not need o-rings on either end of the links with them. The silicone o-rings do work very well though!

[craig303uk]

Originally Posted by heuerfan

Well they solved my porpoise problem and I believe others as well. Another thing to consider is your tailboom length, i believe that can attribute to the porpoise problem.

You can buy complete sets of those orings from members here for a couple of bucks, why not give it a try.

well you'd be the 1st person i've read about fixing the proposing with o rings! for the chicken dance / blade flutter at mid stick yes.

in most cases its down to the play in the feathering shaft and blade grips.

[jamesandyori]

Ok to clean the MH bearings in the frame what is the best way to remove them?

James

[jamesandyori]

I do have some play in the feather shaft area.

As for the o-rings, well the heli never had this problem up to recently. So if my black factory rings were fine and then the next day the dolphin act developed then I kinda doubt that my current rings went bad or if changed the problem will vanish.

1) fix play in feathering shaft
2) learn how to remove bearings and clean them in MH frame
3) o-rings overhaul!

I / (WE) will figure this out!

[jamesandyori]

I got rid of all of the play with the feathering shaft and the dolphin is a bit of a wobble now.

I also cleaned my servos this weekend!

I wonder if the pinion on my main motor is out of shape. But if it was the excess movement would be constant.

James

[jamesandyori]

GOT IT!!!!!!!!!!!!!!!!!!!!!!!!!!!

It was the back servo linkage! It was so extended that it was bowing and flexing!

That is where the dolphin like behavior is coming from. Once I screwed in all 3 linkages equally then it flew rock solid!

I will eventually beef the linkage and because all 3 of my mcpXs suffer from the linkage bending and such.

I am so happy I can dance:


Thanks guys!

James