Roger Hamilton
Senior Heliman
Location: Surrey, England
| Following a long lay up I finally put my Concept 46 back together. However I like to run a fairly low headspeed for hovering around when not in idle up but the heli develops a very smooth low frequency wobble at low headspeeds of approx 1500 or less.
I've never experienced such a strange phenomenon. Most wobbles and shakes I've had on helis have been rough, but this is a really smooth swaying from side to side, like you were actually doing it from cyclic input. The head seems to be geostationary and the body is moving.
I've inspected the machine and I noticed that the blades do not hang completely symetrically, ie, at rest one drops some 2 cms further than the other at blade tip. However, I can't see why. The mainshaft is new and the feather shafts are true as far as I can see. The blades track up cleanly which would indicate that the feather shafts are OK.
Anyone got any suggestions? |
. This is normal at too low a head speed 
