Are you trying to get a Darwin Award?
You are <expletive> lucky the motor rotor didn't grenade. It only takes one rotor bar to bow by a couple of mm or break at one end or a bearing to catastrophically fail and the rotor will seize inside the stator, and tear the motor apart.
Assuming a 2" dia 2" long rotor, at 16800 RPM, the rotor rim speed is 100 MPH, there's over 8000 g of centripetal acceleration, and 500 J of kinetic energy.
At the very least, a sane person would want containment round the motor that could safely withstand half the motor rotor mass hitting it at half the rim speed, and trap any high speed bouncing small parts.
Edit: corrected assumed rotor diameter - I did the math for 1" radius (and assumed a uniform steel cylinder for the K.E. calculation, so somewhat of a spherical cow).