Prop Balancing

[copterdoc]

While at work today a co-worker who runs a local FBO asked me about prop ballancing on RV's since I'm building an -8. I'm going to appologise up front for not having a lot of specific information so please think of this as a general question. He is trying to ballance a new Sensenich metal prop on an -4 that had a wooden prop previously installed. The owner installed the new prop and flew it in for ballancing. My friend removed the prop and re-indexed it to the 11-5 o'clock position. After the ballance was completed with readings in the 0.0 to 0.2 ips range the owner test flew the plane and claims it is worse than when he flew it in. We called Van's and they say the FBO did everything right. Anyone got any ideas or past experience? Is the owner just used to the smoothness of the wood prop? Engine mounts? NORMAL!? Ideas? Thanks!

Brad

 

[jhallrv4]

A good wood prop will be smoother than a metal prop. Having said that, the ips range you quote should be fairly smooth. You also said he flew it in with the new prop, so that would be the reference, the flight to get the prop balanced. It's hard to imagine 0.0 to 0.2 being considered rough, but 0.02 would be better. My Sensenich is the only prop I've had on the -4, but I hear great things about the smoothness of wood props. I wouldn't want the hassles associated with wood though.

Jeff

 

[jhallrv4]

One more thing...I originally had my engine mounts WAY to tight...(conical mt. O-360-J2A) much smoother since I followed a service bulletin from Aviat Aircraft. (Husky used to have conical mt. O-360)

Jeff

 

[94kb]

Jeff, I am building a 4 with an O-360C1G off a Husky. I have a Hartzell and am using the Lord motor mounts. Is the Aviat SB about re-indexing the prop? Does this require different inserts in the prop flange?

Ken