Diagnosing and Fixing a Broken Gimbal Brushless Motor

After a recent road trip which I brought my Phantom and my hexacopter, I found that the Arris CM3000 3-axis camera gimbal on the Phantom became stuck.  The pitch motor would only move about 1/16 of an inch.  Something was blocking it.  I didn’t want to give it too much force for fear of breaking it.

I found a replacement for the motor online for about $18.  But before I ordered one from China and had to wait 17 million weeks for it to arrive, I thought I’d tear apart the broken brushless motor and see if I could fix it.

I’ve never torn apart a brushless motor before.  It was not hard.  I popped the clip on the drive shaft and unscrewed the shaft screw.  Then the outer cover came off with a little force.  It did not want to come out because of how strong the magnets were.

The problem was visibly obvious as soon as I had the cover off.  A couple of the magnets had broken and a piece of them came off, lodging between two other magnets (above).  I’m guessing the magnets were cracked during a Phantom crash, and eventually the piece broke loose.  You can see the loose chunk below:

I cleaned out the debris, put it back together and it appears to be working again.  I just hand tested it though.  A real flight test is up next.