[Katamarino]

Brand new RC Allen 22-7 installed on Sunday. My A&P and most others say it's worse than they've seen before. One other guy who also installed a brand new 22-7 two weeks ago says his does the same.

After that initial 20 seconds it works perfectly. Haven't spoken to RC Allen yet; my A&P suggests running with it for a while to see if it settles down (warranty is good for a year).

Thoughts?

[cockney steve]

Bear in mind, i'M NOT A PILOT!

AIUI, This is a gyro- instrument . Until ir's spun-up, the flywheel is just a dead-weight
with no gyroscopic stability or precession. It is possible there will be resonant imbalances,passed -through as the operating -speed is attained.

Could this be the cause?

[rf3flyer]

Clipped from p36 of: http://www.kellymfg.com/images/RC%20ALLEN%20Catalog.pdf

My guess is that being a vacuum instrument it's starting to run up just as your engine is getting going and is itself probably a little lumpy and vibratory. Can it be caged until the engine has evened out and the vacuum supply has stabilised? If so does that improve things?

[GolfHotel]

Please bear in mind I am a pilot Hello Steve

I've never seen one wobble quite that much, it looks a bit under damped to me. But if it settles down and works well in flight just a call to the manufactures might give you a steer as to what to do.

[TonyC]

Was the aircraft moved around a few minutes before?

Brand new RC Allen 22-7 installed on Sunday. My A&P and most others say it's worse than they've seen before. One other guy who also installed a brand new 22-7 two weeks ago says his does the same.

After that initial 20 seconds it works perfectly. Haven't spoken to RC Allen yet; my A&P suggests running with it for a while to see if it settles down (warranty is good for a year).

Thoughts?

[Katamarino]

Doesn't seem to make a difference whether it's just been moved, or has sat for a few hours.

[TonyC]

I think you will find its been damaged inside during shipping. I had a similar thing with a DG once an internal part had come loose.

Doesn't seem to make a difference whether it's just been moved, or has sat for a few hours.