Assemble
the prop balancer and find the shaft that is a close fit into the
propeller. Put the shaft between the magnets so that it touches one
magnet and is close to the other. It may be necessary to adjust
the width of the balancer to do this. The prop will rotate and then
stop. Mark the prop with a marker pen at the lowest point. Spin the prop
again and it should stop in the same position. Draw a vertical
line downwards from the shaft on the lower blade. This is the area where
you must remove material to balance it. If the prop stops with the
blades level the material can be removed from the hub or better
still from the lowest edges of each blade. Material removed from towards
the tip of the prop will have more of an effect on the balance. Remove
material with a file from the front of the blade ONLY, i.e. the convex
side which is the same side as the drive dog slot. Use a fairly large
file, the small swiss type files are not coarse enough. Keep checking
the balance of the prop. When it is balanced it will be possible to spin
the prop and will not stop in the same position each time.
To sharpen the prop use the file again making file strokes towards the
edge of the prop until it is sharp. This must only be done on the convex
side, front side.Sharpening the prop can be done before balancing but if
not then rebalance after sharpening. The trailing edge of the prop
(thick edge) should be squared off so that it has sharp edges , i.e, 2
sharp edges.