Tuesday, January 27, 2015

Dynamic prop balancing

Today I flew the HWD to have the props dynamically balanced.  I've been wanting to do this since I got new engines and props a few years ago, and now that they are all settled in it seemed like a good time to go for it.  I met Brian Sullivan from Sullivan propellor on the South ramp at HWD.  He came in his truck from their shop down the road with his assistant Nick. They got it done pretty quick, both engines took about 2.5 hours. They are outside taking readings and I'm in the plane running each engine up while they take the measurements. Brian really seems to know props and know what he's doing. 

My right engine had a .5 reading. One blade was basically heavier, but it had no static weights on it so for that engine, they had to add offsetting weights on the other side to balance it. For that, they drilled two small holes in the spinner backplate.  

On the backside some small washers are stacked there until the machine reads perfectly balanced. I ran the engine up about 4 or 5 times and each time it ran smoother. 

End result for the right engine was I went from .5 to .04. Definitely felt significantly smoother. 

The left side measured .4 but just needed to have the static weights adjusted. They removed a big one and we went back and forth a few times adjusting different static weights until that one read .04 as well.  

I'd say the props/engines are definitely smoother. I used to feel a little vibration in the yoke and that's gone now. I flew around for an hour afterwards and it's definitely noticeably smoother. Maybe not quite turbine smooth though. Worth $800? Hard to say but I think my Baron is now one of the smoothest running piston planes I've been in.   :thumbup:

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