Balancing a Wind Generator prop

[slowbat]

Hello Cruisers,

I have an Air-X with three carbon blades, any advice on how to balancing the prop? I understand it can make the quiet down a little bit.

All the best,
Dan

[Jim Cate]

G'Day Dan,

In my experience with our Air-X it isn't a balance problem but that the sockets in the hub don't align the blades precisely enough. What I have done is to lay the blade assembly flat and very carefully measure the distance between the blade tips. Slack the mounting bolts slightly and keep adjusting the blades until the distances are exactly equal. This has reduced vibration significantly for us, but does nothing for blade noise. For that, careful sanding with fine wet/dry paper (up to 800 or so) has helped somewhat but there is really nothing that will change the basic design and the associated wind noise. Replacing with the "blue blades" is reputed to cure the problem, and the next time I break a blade I will go that route.

Cheers,

Jim

[sailvayu]

Use a home made balance beam, with a stick and string, find the lightest blade and use that as your balance weight then just adjust the others to match. I tried a digital scale once but got better results with the balance beam.

[model 10]

If it were an aircraft propeller you would hang it from the center of the hub with a simple fitting and then balance the the whole assembly blades and all, probably at the hub end. You of course need to check the track of all 3 blades and the length also.
Im my very humble opinion, balance is probably not the problem, noise wise. Balance would affect vibration but not so much the sound.