Prop Balancing issue
Hi everyone,
I'm trying to resolve an issue with prob balancing (presumably) causing vibration in the engine.
The combination is an MT 2 blade fixed pitch with fibreglass coating and metal leading edge on a Continental IO-F-240-B (Fadec).
The prop was statically balanced and admittedly one blade is noticeably heavier than the other, but with some weight added to the bulkhead, it's perfectly balanced statically.
With the dynamic balancer (Vitratex) and a around 15 grams strategically placed we get near perfect results, .02 on the display (for those unsure, anything up to .25 is the norm on this unit) so good results there. That is at 2,300rpm.
My assumption is therefore that the engine / crank is A-OK.
However at 2,450 and above a vibration starts and up to 2,850 redline, it's quite bad, the higher the RPM the more vibrations present.
I'm trying to work out why?
My thoughts are that under high load, one prop blade is either twisting or bending differently to the other, thus causing an inbalance. It's the only thing that I can think of.
Any suggestions?