Noticed that serial crasher was being given conflicting advice, like:
Cut the prop to the required size.
Don't cut a prop.
Balance it. Scrape the tip. Scrape the back.
Don't balance, use the prop as it is...
Etc.
The fact is:
Modifying a prop should NOT be done by anyone except an expert on the subject.
The tip of a 6" dia prop on a 2200kv motor on a 3s lipo is doing about
600 kmphImagine the effect of even slight modifications!
However, all props must be balanced.
If you can, get a magnetic balancer (rather expensive)
Or get a hand held balancer (cheaper)
If without access to either, locate a dowel that fits the hole in the prop.
You could use a knitting needle or a drill bit.
You can even get reed dowels from the base of flower bouquets. Find one that fits the prop firmly.
Balance it on the edge of two equal height glasses/tins/katories.
Add weight to the lighter blade BY SPRAYING CLEAR LAQUER OR PAINT on the rear side.
You could even use nail polish and a brush.
Wait till the thinner has evaporated and check again.
Once you hear the sweet sound of a balanced prop, you'll know it was worth the effort!