vibe issue

[Adrian]

Trex 600e flew fine in pod and boom.
fitted into align md500 with extra bracing to doghouse and in the tail. Gets to just befor lift of and shakes real bad.

I have -3 0 at mid stick +10 and throttle curve of 0 25 75 75 75 pitch 25 inh 57 inh 82 hacker 1100 motor running 5000mah 6s.

Would the pitch and throttle have to be alterd at all? cheers

[Steve]

Does it shake when it's actually in the air, or haven't you got that far yet?

If it was fine without the body then it's likely to be harmonics in the body shell. You could try tweaking the throttle curve and/or adding some strategic deadening mass to the inside of the fuselage - maybe some dense sticky-back foam or something? Anything to alter the harmonics of the body and take it away from your problem frequency.

[Boggy]

I would think Steve has the answer Adrian.(fuselage resonance) Try a large blob of blu tack add it to the tail fin at the bottom and respool the heli if it dosen't help move it around.

[Adrian]

its just the tail that vibes well bad just before lift off, so i havent left the ground yet! dident know if adding +3 od 4 degs at mid stick would solve it

[Boggy]

yep my eurocopter did it it now has an alloy wheel balance weight in the bottom of the fin and two inside the rear of the tail boom . Changing the lift off point (with pitch curve) or motor rpm(throttle curve) may well also clear it. Its a matter of stopping the vibes of the motor or blades being in harmony with the natural vibes in the fuselage.(or with extra weight changing the fuse' vibes)

[Adrian]

yep my eurocopter did it it now has an alloy wheel balance weight in the bottom of the fin and two inside the rear of the tail boom . Changing the lift off point (with pitch curve) or motor rpm(throttle curve) may well also clear it. Its a matter of stopping the vibes of the motor or blades being in harmony with the natural vibes in the fuselage.(or with extra weight changing the fuse' vibes)

do you use "0" at mid stick or not ron, i was thinking perhaps if i added +3 degs at mid it would be off the ground and vibe free

[Adrian]

well a little more foam and a change of main blades to some that were 2oz heavy er seemed to of solved the vibes, now it just tracks back at me when in the hover.....adjusting needed now