A significant amount of effort is put into making sure that all APC propellers are as close to being perfectly balanced as possible before they are shipped. Therefore, it is unlikely that a balance correction will be required. The following procedure should be used to check the balance of a propeller.

>We recommend that the drilled hole not be used for checking balance since it is sometimes not as straight as it should be.  Instead the user should check the balance of all APC propellers using the precision molded hole at the back side of the hub (see illustration below).  The tapered part of the balance cone should be used on this side.  A pin that is smaller than the through hole should be used to prevent any interference with the drilled hole.  Finally, a washer (or the flat end of the balance cone) should be used to secure the propeller at the forward face of the hub.  Similarly to the way it mounts to the motor.

If your propeller requires a balance correction, we recommend that material be removed from the upper and lower surfaces at the tip of the heavy blade.

Centering Propellers on Motor Shaft

We recommend that APC propellers be centered on the motor shaft in the manner illustrated below.  The through hole should be oversized for each particular motor shaft so that only the locating ring centers the propeller.

In addition to the supplied Locating Rings (electric propellers only), aluminum tubing and/or fuel tubing can be used to center the propeller on the shaft.  The standard through hole diameters for APC propellers are 3/16”, 1/4”, and 5/16”.