If you get vibration, then you must remove and balance the fan, and also look for blade rubbing before running it up!

This is standard with all EDF's.

You - MUST - check it out.

John appears to be sending you a new blade set.

Look in the F-35 thread here where I outlined the proceedure for testing and breaking in the EDF.

You must sand the blades slightly to avoid them rubbing with the shell.

Because this was not done on your EDF, the blades contacted the shell which broke them off..

The blades will splay out and hit the shell because of centripetal force... you must sand down about 2mm of plastic to avoid this.

The best way to do it is to spin the fan on a drill against fine grit sandpaper.

It only takes a few minutes to do but it means the difference between a broken EDF and a good flying plane.