On that last picture, note the large silver ring at the "business" end of the Scorpion motor. That's a ball bearing! It sits inside the spinning part of the motor and provides extra support.
SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz