Ok, I'm not really sure what happened, but for sure the ESC (Schulze 18.46) is toast.

Comming out of a hourglass (last corner) the plane sounded like it threw a blade.  A blurring sound for about a second and then the motor stopped.
 
Initial thought, at the field,  was that the shaft had slipped on the collett, due to the forces on the prop in the manuever,  causing a severe vibration that caused the shutdown of the system.

At home, switch out testing showed that the ESC was not working at all, kaput.  Everything else was ok.

I wonder now if the ESC just died and that is the sound that a dying ESC makes, like maybe pulses in the wrong sequence? or was it the slipping collett?

Any thoughts?

Hi Frank,
Diagnosing by written decriptions of sounds is getting to be awfully common around here!
The "blurring" sound is almost certainly the sound of a missing or misfiring commutation sequence.
I've heard it before, but at 3 kiloWatts it's more of a Bar-ar-ar-ar-ar-appp!
This can happen because of a transistor failure, or when two of the motor wires short to each other, or if a motor-ESC connector on one of the three wires comes loose. (Don't ask how I know!)
The end result, whether caused by the ESC or wiring, is a fried ESC.

oh well,
    Dean P.

Dennis
Frank's collet was loose and the whole prop & spinner and all came off the first time it flew
In that case the motor kept running but I was able to open up the cowl and pull the arming plug.
After tightening things up things went back to normal. Looking back could have set up the ESC
failure?
 

What have you changed, what have you kept the same?  Obviously you've changed the ESC -- how about the motor, the connectors, the wires (yes, the wires -- you can get hidden breaks)?

You mentioned that one of your connectors was a bit loose, but that you reconnected it and it seemed fine -- did you replace that connector?

If you did replace connectors, did you replace all the connectors?  Did you change the brand of connectors?

Does the Schulze ESC let you read a post-mortem report?  There may be clues there.

Do the motor bearings feel good?  No grind when you turn the motor?  No wiggle when you push the prop shaft from side to side?  No end play when you pull and push on the prop?  The maneuvers were high load, but they were also high G and high rotation rate -- I'm wondering if you don't have a loose bearing that's causing an intermittent short in the motor.

"Slight bind until cooled" and "black crud around the rear bearing" add up to "trouble" to me.  I'm not sure what may be causing it -- but if your motor seized up in flight it wouldn't make life easy on the ESC.