ORIGINAL: KC36330

back in the days i used to take 18" props and cut between 8 and 10 inches off them to get the RPM up while breaking in ducted fan engines on the bench, had to use the larger diameters because of the thicker hub so they'd take the RPM, I've also cut down 9" pylon props to 5-6 inches size for .21's with great results. the maximum you can take off really depends on the prop in question. as for balancing, just make sure you balance it before you run it. most of the time i don't go as far as balancing out the heavy side of the hub on props less then 14" in size unless they are very high RPM applications, I'll just laterally balance them.

kc

EDIT: here is a pic of a few of those cut down pylon props, as you can see they have 3" of their original diameter removed.