912 S heavy vibratios as putting less power.

Re: 912 S heavy vibratios as putting less power.

by bill martin » 13 years ago

bill martin

10 757 0

Jorge,

It sound a lot like what Ralph described. Worn isolation pads or loose engine mounts can cause vibrations which only become noticeable at certain angles of pitch or roll until the wear becomes bad enough to be noticed constantly.

Bill.

Re: 912 S heavy vibratios as putting less power.

by MARK JACKSON » 13 years ago

MARK JACKSON

12 332 11

Hi Jorge

Warp drive props are a bit hit and miss. I have tried 5 different new ones, all of which were not acceptable, until I finally found one set of blades that all had the same amount of twist/washout. I made a simple gauge to check the blade twist.
I'm not sure how they are made but there always seemed to be two blades the same, and one with a different amount of twist. I wanted a nickel leading edge prop, but gave up after three attempts and settled for a standard one.

It meant that it was impossible to set up the blades properly, and no matter what you did you would always have some vibration at a certain RPM.

The prop that I have now has the same amount of twist in each blade, the individual blades are 5 grams difference in weight , but when built and set the prop is perfectly balanced, within 0.1 grams, and it tracks within 1-2 mm :-)

Before you do anything, try a different prop, maybe borrow one to try.

This is after you have checked you carb balance and engine mounts first.

Cheers Mark

Re: 912 S heavy vibratios as putting less power.

by jorge wenke » 13 years ago

jorge wenke

2 5 0

Mark,
thankyou for telling me your experience. I think exactly as you do about Warp Drive behavior when propeller effort changes. I also belive 3 blades twist not equal at puttig less power.
Im going to check engine engine mounts. Carburator balance is already done!
Thankyou again
Regards,
Jorge