I am an ME and have been building & flying helis for the past 20 years. When I finished
college I gave it up (Hirobo Cobra). This winter I bought a DF IV to fly around in the garage
& the camera was kinda cool too & it got me interested in gas helis again. Anyway, over the past
several weeks I decided to get back into gas helis & bought a Caliber 30 ARF kit w/ the OS32
SX-H engine and Futaba FP-6VH radio. I upgraded the kit gyro to a GY401.

To make a long story short, this thing has experienced violent shaking since the minute I first flew it.
I have statically and dynamically balanced both the tail & main blades & checked the tracking & pitch
many times. I know the mainshaft isn't bent because you can spin up the blades to max rpm @ zero
pitch on the ground and everything is smooth, but get in a hover and it will be smooth for a while and
then start shaking in larger & larger amplitudes and if I didn't set it down, it would shake itself apart!

I'm ready to take it back & get my money back & buy something else.

Anyway have and ideas or comments?

Thanks,

A frustrated Caliber 30 owner

Hello, are the swashplate itself and his course all right?

Yes. I've gone over inch,bolt & nut on this thing and it's driving me nuts!
It is a harmonic vibration that randomly occurs for no apparent reason.

Thanks for the reply though.

I'm betting low headspeed. Change your throttle/pitch curves for less pitch and more throttle.

Believe me I've tried every combination of pitch/throttle available on the radio that came w/ the package.
It's a Futaba FP-6VH and is no more advanced than my 20 year old Airtronics radio (other than it's about 1/5
the price). I talked to the guys @ great planes & they seem to have never flown this combination even though
they sell it as a package. They all seem to use the EMS w/ CCPM. The package uses MMS with the whole servo
tray sliding back & forth for collective.

are you running training gear on it???
if so calibers dont like them

Its probably low head speed combined with bad tracking.
At hover pitch, about 6 degrees, I run my OS32 at 65% throttle to keep the head speed high. I also found that if the tracking wasn't correct, it would cause the shakes as you describe. Check the tracking just as the bird gets light on her feet not at zero pitch.
As for training gear, I never had the problem with the shakes, but I did have a problem with one of the legs swinging up into the rotor disk. DOHH! Those plastic balls go quite a distance when hit with a 200mph bat!

mazdman,

Try to loosen up your main blades bolt a little. not too loose though just in a way that you can move the main blades freely both of them without giving to much effort and try it. I assume that you have not crash this heli before? . I have a caliber 30 also and that was my problem before no she flies so smooth and I love it.

I've seen some calibers that had the low head speed oscillation that would become a training gear oscillation if the headspeed was increased. With no training gear present the oscillation cleans right up with higher head speeds.