>>I, too am interested in what measures can be taken to reduce interior
noise. Do any of you know of the full range of options? I would guess
without knowing that there would be a weight penalty - am I right? Al.<<
Me too. Kwip is getting quieter as individual vibration sources, such as
silencer touching cowling, get fixed. After 100 hours the gearbox is
quieter too. I'm surprised Kim's is so noisy after 300 hours.
Upholstery helps with the higher prequencies and doesn't need to weigh
much.
Balance the prop, properly. that makes a big difference. Also make sure all
3 blades have the same pitch to within a 1/10th of a degree if you can.
Setting up a Warp Drive needs to be done carefully. First pull all three
blades outwards , HARD, with a the bolts just nipped, then adjust each and
tighten a bit at a time, checking after each tightening. They do move. A
big plywood "spanner" to fit over the blade close to the root will help to
turn it with the bolts partly tightened.
I've just noticed that the rear bulkhead booms loudly if thumped. I guess
it will amplify any vibration. Think I might add lightweight stiffening
next winter.
Graham
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