Blown rotor
 

http://i113.photobucket.com/albums/n...EN206/neo1.jpg

What would be the cause off this ?

Being bonded and not sintered (I think), bonded doesn't have the longevity of a sintered rotor

It could be one of a few things:
1. Overheating. If the gearing was way off, or there was binding then rotor failure is one of the results.

2. Bonded rotor - this is basically where the magnets are glued to the rotor, temps rise and the magnets fly off.

3. Some massive impact - though unlikely considering the lack of marks on the can.

4. Manufacturing Defect - it can happen!

There are others too! Best bet would be to send it back to your Reedy distributor/LHS to see what they say - if it's a warranty job then :thumbsup:.

+1

I would add also the free spinning and rev too high (bonded rotors have a limit of less 60000rpm I seem to remember)... =centrifugal force

I agree with this last one, happened to one club mate and seems to be frequent with older motors.

Not many brushless motors should be revving higher than 60000rpm to be honest...

Particularly those made by car manufacturers as the quality seems poor in comparison to air designed motors (exceptions appear to be Castle CM2200 and CM2650 motors - which are Neu motors anyway, and Tekin motors. Novaks are pretty good too, though I'm not keen on Speed Passion motors).