Massive vibration problem w/Raptor 50 V2

[awr]

I'm in the final phase of setting up my Raptor 50 V2.

The engine is tuned and the blades are balanced. I've double checked everything in the head, and it's
all fine.

I'm trying to ensure that the maiden voyage off the ground won't be the last time I see all of the original
parts in one piece in the same condition they were installed, so I've been running the helicopter on the
ground with the pitch curve set at a flat 50%.

My problem is that every time I go from quarter throttle to mid throttle, the head starts to oscillate
(left and right when viewed from the front of the helicopter) violently until I drop the RPM. I've changed
blades, and double checked the pitch on the blades and the flybar, but they're all fine. The blade
tracking doesn't seem to be the problem.

I'm stumped. Can anyone suggest what might be wrong? Blades too tight in the blade grips?

Thanks for your help.


Wayne
Calgary, Alberta, Canada

[Mike SVOR]

blades are probably too tight.

Set it up so that if you turn the heli on its side, main rotor facing front to back, and shake it, the main blades will fall slightly.

Too tight, and you get the 'death wobble'.

[Dino Spadaccini]

you might have to much head speed and not enough load on the blades if your not running a govenr then back the throttle curve down some

[ghtracey]

you might have to much head speed and not enough load on the blades if your not running a govenr then back the throttle curve down some
^^^ and if you have a govenor on a new model without a broken in engine, disable it until you are sure that your setup is correct. A govenor can hide an overlean condition and cause engine failure.

[kama1]

while your at it ...check the flybar seesaw screws.
had vibration issues not to long ago and one of those screws worked loose.

[xrbcoronalogoflyer]

wayne...i don't know if you solved your shakes, but if not, check your rx battery...i replaced the 1500 aa nimh with a lipo regulator setup, which, after test flight, eliminated my shakes...since the shakes only appeared after the first flight, or at the end of the first flight, i suspected that the servos were acting up or not holding because of low voltage...i was right...5 full-sized servos, gyro, synthesized rx, and switch harness were sucking voltage for my puny, old pack (confirmed voltmeter on load)...here's a pic of the sick battery...fwiw, worked for me...btw, i posted more info on my rap50v2 in this thread...

http://www.helifreak.com/showthread.php?t=48235

-ken

[rv4r30]

You could be running you engine too lean if nothing else fixes it.

[heli]

You could be running you engine too lean if nothing else fixes it.

Do the blades appear to go in and out of track? If so double check your thrust bearings.

I have seen this a couple times on the 50 SE.

See the photos.

Notice the layout. There is one race that the inside diameter 6.23mm and the other is 5.98mm. Make sure the larger diameter is closest to the head.