FBL Gyro 450x/ar7200bx Pops Up And Down

Apo234

New Member
My father has a Blade 450X with the AR7200BX and when you go to take off with it off the ground and it is about to lift off the ground it will just like pop up and down by it's self and I can not figure this out. It does not have any vibration problems that I can find or feel, the AR7200bx is now on like 5 pieces of tape because I was trying to figure out if it was vibration that was causing it. I can not find any info about other people having this type of problem and my father loves this helicopter and this time I can not figure out how to fix it. This helicopter has been fine for years, he has crashed it a couple of times. I have repaired it and it has always flown fine after. It started doing this last summer and it was not after any type of crash it just started happening one day and he stopped trying to fly it. I forgot about it, and am trying to get it flying again. I do not know if like the AR7200BX just went bad or something changed or if he clicked something he was not supposed to. If anyone has any tips I would love to hear them! Thank you for viewing! This is my 1st post on here!
 

Smoggie

Well-Known Member
Check that the main shaft does not have any vertical play (just grab the head and pull and push it up and down).. If there is some play then this will lead to unpredictable and sudden collective response.
 

Tony

Staff member
Vertical play will definitely cause the issue. Firs thing that came to mind was the blades are on backwards. It can still fly, but it will be uncontrollable. If you can, post a picture of the helicopter so we can take a look.
 

Apo234

New Member
I thought I should update this... The shaft did have play in it, It was not much but there was some. After I fixed that the helicopter flew great again... for like 6 flights and then on the next flight it took off and just crashed in to the ground, I do not know if the AR7200BX is bad or one of the servos went bad. Still in pieces in a box.
 

leedude1

Member
The AR7200bx are realy pretty good units and thats, thats what I fly on my all my birds 450 and up . I would have to agree with the comments above and say there was something mechanical going on that caused the erratic behavior. Binding , play or other. 450 is a nice bird, dont give up on her.
 

murankar

Staff member
First off with out crash scene data it will be hard to figure out. Some things that could've caused it to eat itself is your elevator servo failed in some way. If the horn stripped, servo died or just went limp then the swash could drop in the back, which would have caused a boom strike. It would have made a pretzel out of the kit.

If the blade grip link popped then it cold have done the Same thing.

Servos going limp is going to be pilot error or a mechanical joint failed, solder or crimp. Pilot error is easy to fix. Shoe goo your servo leads into the fbl or hot glue them. Hot glue the crimp and solder joints.


It could have been a bad fbl but unlikely


Nesting your running a DX6 or similar radio check the stick output monitor and make sure the sticks do what they should be. Specktrum radios have been known to lose a potentiometer.
 
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