After finishing making up 6 1/8" bit with the motor, the driller lifted the whole assembly by BX Elevator then pushed towards Drawworks/Mud tanks side and rested it on the rotary mat to allow the crew to remove the bit breaker by winch from well center. While winch was being prepared to lift the bit breaker, the BX elevator opened and as a result, the drilling assembly which was in a tilted position fell on the rig floor (between the DPs setback and adjacent V door post) and bounced off the rig floor and fell into the ground. Motor got bent, No injury to Personnel.