Prop Balancer

Only 10 hours of use and the prop had to be refinished! Even on clean pavement the nose wheel kicked up a lot of stuff until installing the nose wheel fender, which works very well. The only drawback was that pushing the plane backwards causes the nose wheel to swing 180 degrees. Not anymore. The fender gets in the way. But I still recommend the fender.

So now, with all the repair work, is the prop still in balance?

The whole deal with a prop balancer is arranging a center hub that fits the prop center hole securely and rides on two 'knife edges'. Turns out to be simple. I used 1/8" aluminum plate, but 1/4 " plywood would do. The trick is putting the 1/4" steel rod snugly in the center. For this you need a lathe. Sorry. Don't even try this without a lathe.

Both discs fit OK, but still, four small pieces of 1/8" masking tape on the edges made it fit nice and snug.

Now the steel tube rides on 1/2" aluminum tubes mounted on wood. All this is scrap you've got laying around from building the airplane. The aluminum 'rails' have to be perfectly level and parallel, of course.

The amazing thing is to watch the prop balancer work. Just set the prop in place and stand back. It moves all by itself, slowly and surely, until the heaviest part is at the bottom. Lead weight is seen above taped to the light side temporarily until the prop no longer moves by itself. Then a small hole is drilled in the hub and the lead set inside and finished with a glued in wood plug and varnish.

This setup is so sensitive that you MUST close all doors and windows to avoid any drafts. A coat of varnish on one blade will make a noticeable difference.