450 Strange problem with blades on a 450

[holtneil]

HI all now this is a strange one for you all , i have a copterx 450 black angel and for the last year i have been having strange crashes do to no lift , they are carbon fibre blades 325mm 4.2mm leading edge and weight of 18g a blade , so i went and got the carbon fibre flame blades still for the angel , 320mm 4.2 mm leading edge but are 28g a blade .
so this morning i took heli out with a new set of light weight blades and the heli was all over the place starting to yo yo up and down ( it was windy this is the uk lol ) and then total loss of lift , so thats new blades smashed and main gear picked up the bits
Rebuilt it set up the same as i always do but this time put the flame blades on , took heli out hover was more stable yo yo was no way as bad .
Now thinking back over the last 4 weeks i have never had loss of lift or crash on the flame blades , but every time i put the carbon standard blades on its has a bad flight
Its hard to find carbon blades that have the weight and most i have found are not 28g a blade , so what can i try now are wooden blades as good or do i need to get bigger blades , i am at a loss really am i look at the problem the wrong way and its not a blade problem , i am building an airwolf so dont want this to crash i will leave some links so you can see what blades i am talking about any help guys would be great as this is costing lots of down time fixing
this is the heli
http://www.ehirobo.com/rc-helicopte...50-black-angel-flybarless-helicopter-kit.html
light blades
http://www.ehirobo.com/carbonhobby-...s-325mm-main-blades-for-trex-copterx-450.html
heavy blades
http://www.ehirobo.com/rc-helicopte...p-450-class-320mm-main-blades-1081159645.html

 

[Lee]

I don't think its got anything to do with your blades.
It will be something in the mechanical or electrical setup.
We need more detail.
Servos, FBL unit, radio, settings etc..
The more info the better. And video would be even better.

 

[murankar]

The yo yo deal could be due to wind. Translational lift will cause the heli to raise and lower depending on wind direction or nose direction. When the nose is going into the wind it will lift without your input. If the nose is traveling away with the wind then it will drop without input from you.


Lack of lift could be from lack of pitch and/or head speed.

So what kv motor and pinion due you have?

Sent from my LG-E980 using Forum Runner

 

[holtneil]

WELL done Lee it was a gain problem i used to have analog servos and on the copterx gyo which is the same as zyx etc gains need to be 20% ,but wheni changed to emax digital the gyro default is 40 % now the heavy blades must have corrected the high gain , but when i fitted the light weight ones ,all my problems started thats why i looking at a blade problem , i reduced gains down to 30% and its sorted i even got the expo down to 12% , well happy thanks guys , but while your here LEE when i put the airwolf body on will this know out gains as to the extra weight , i was reading when landing to roll in at about 45 degs to a landing not stop to a hover and land why ?

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sorry cant edit i mean knock out gains

 

[Lee]

You may find the extra weight will dull down the gains, allowing you to increase them. But only experimentation will tell you.

 

[holtneil]

Hi Lee , i have gains down to 25% flys ok on the light blades but on FFF its bounces a little so i lowered the gains more and it got worse so i put heavy blades on and the bounce has gone at 25% , so i will leave it with the heavy blades even tho they are smaller at 320mm , all fun mate i did find a write up on advance setting for this gyro its 3 pages long and most went over my head lol

 

[Lee]

Cool. keep us up to date on how it goes