Re: Looking for DynaVibe in Phoenix
Quote:
Originally Posted by
JetFox
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I came to the conclusion the the prop dynamic balance with Dyna Vibe help me to reduce the vibration, however I did not achieve a prefect numbers of 10 IPS or less through the whole RPM range. The lower the numbers you get, the harder it is to re-produce during the next test. I will do a balancing on a metal prop on a C145 next and see how Dyna Vibe works out there.
Regards
Peter Buehlmann
Kitfox4-1200 IVO prop inflight adjustable on Rotax 80HP
Hey Peter,
I don't want to discourage you, but 10 ips would represent a lot of vibration. That would be a very high number. When I balance a prop, I aim for a velocity of less than .05 ips. If it's not just a simple out of balance propeller situation - for instance if you have something loose, or a gearbox or engine problem - it will be hard or impossible to balance the prop. It will be interesting to see what results you get with the C145.
Re: Looking for DynaVibe in Phoenix
Hi John, after a hot summer in Arizona I am back in the hangar. Yes you are right, 10 ips is not a good number. This was a typo, I tried to achieve 0.10 ips. I did get 0.10 and below but not through the whole RPM range. I balanced for around 4800 RPM and I got it down there to 0.09 to 0.05 ips. I am still wondering why I do not have an equal result through the whole RPM range as the prob balance should stay the same in regards to weight distribution over the prop. I have to assume that engine vibration on different RPM influenced the prop balance result. Anyway, I have a much smoother ride around my cruising RPM of 4800. The vibration around 3200 just after pulling the power on a final has significantly increased. However this is just for a short time on final. I am happy the way it is now.
I have not done the C145 yet, will report back later.
Regards Peter
Re: Looking for DynaVibe in Phoenix
Try clocking the prop differently. What I mean by that is rotate it one set of
bolt holes and try again. That can make a huge difference.
Jeff
Quote:
Originally Posted by
JetFox
Here is an update from my balancing. I did remove all the added weights and measured again, just to prove that I am out of balance...
Re: Looking for DynaVibe in Phoenix
Jeff, I will give it a try next time I remove the prop.
Re: Looking for DynaVibe in Phoenix
Peter not that I've ever jumped in to a fun task without double checking the basics - but - did you check the prop track? That will create the condition you're describing.
Re: Looking for DynaVibe in Phoenix
Delta Whisky, no I did not check the track of the prop blades. I did not consider it as important as these blades are very flexible (Ivo Prop). I did it on metal props on other planes. Well this is a good input and easy to do. Currently the prop is off, will check it once it is back on. Will report on the findings, thanks for the hint.
Regards
Peter Buehlmann