... Panel Optional Parts Optional Parts The controller feature: 1)Low inertia, high speed, medium torque servo motor, precise ... control range: 0-5000RPM. Needle up/Down Correction Thread Trimming, wiping, Back tacking presser foot lift control. 4)Needle ... trimming, thread wiping, back tacking, presser foot lift solenoid short circuit protection to make the power circuit more reliable. 6)Low noise, low ...