For the engineers - torsional vibration? - long winded! - Help!!

[penfold]

I read a monograph on the subject of harmonics in rotating systems a while ago, written by a chap who worked in the aircraft industry in the US; he had interesting things to say about how best to eliminate such things. I'll try and remember to track it down when I get home and post a link to it.

 

[Hypocacculus]

Well - rolling, yawing and surfing downhill in F5-6 and three reefs in this afternoon was not the best test conditions but my impression was that we were touch early 6 knots when I reckon we would have been over 7. But very unscientific. I think in very lights winds it will take the fun out of ditch crawling and short tacking etc. I'll let you know.

Thanks for the feedback. I shall continue to watch with interest!

 

[LittleSister]

my impression was that we were touch early 6 knots when I reckon we would have been over 7.

But presumably that's using the prop from the old set up? You quite likely need a different size/pitch for optimum results given your change of engine and gearbox. (apologies if I've missed/forgotten something said earlier.)

 

[dur]

But presumably that's using the prop from the old set up? You quite likely need a different size/pitch for optimum results given your change of engine and gearbox. (apologies if I've missed/forgotten something said earlier.)

No - I was just trying to compare having the fixed prop on compared with the feathering job. Very subjective!

The new engine was specifically sized around the feathering prop and this has been crossed checked by Darglow's own calcs.