Hub balancing?

The prop should really rest in _ANY_ position, including level, with no preference to the angle if it is truly balanced in all ways.

If you are going to go through the full effort...

Correct run out, concentricity, and twist by mounting the prop, and checking the blade tips are in the same plane, and the angle of the blade is identical, and the length of each blade is identical.  Alter the bore or trim the tip length, mark and file the face and back, until this is corrected.  There should be very little, if any, correction needed on modern molded props, although wooden props require more effort.

Then proceed to balance the system now that it is running true.

Remember that you must reseal wood propellers after filing, sanding, carving, or otherwise reshaping.  A fuel proof sealant is necessary.  You can apply some more of this said fuel proof sealant to the prop to ADD weight to balance, instead of merely subtracting weight from the heavy side.

Phil

It's important to know which hole, front or back is the supposed center. Use the cone in that one and the flat on the other side. Read this from APC regarding balancing:
http://www.apcprop.com/v/html/balancing.html

This video tells the story a little better, and the balancer is one that lets you find the heavy spots for all 360 deg. I haven't ever used the velcro trick, but I have packed the holes in back of the hub with clay. That's best. Removing hub material is my last resort.

https://youtu.be/N02NHYrpA0g

Rusty

Good video there.

Phil

Great video Rusty, thanks.

Jim

That is a good video! I didn't realize I already had the tools to balance hubs.

I mentioned using clay earlier. If you pack clay into the back of the hub, you have to seal it to keep it from drying. A dab of JB skinned over it is good for that. Personally, I don't worry too much about the hub unless I'm running a high RPM engine like a Tee Dee or Norvel. Not to worry, I will get the Tach Race props in tip top balance though. Rubber duckies are frequently impossible to balance. I've never seen a brand of sport prop that didn't sometimes have a really bad one in a batch. And once in a while a batch has one that is well balanced.

I think it works on the bearings more than affecting the whole machine as an unbalanced blade will. It's probably not much of a problem with ball bearing engines either. I'd be interested in any opinions on whether or not my thinking is correct on those points.

Rusty