DC Servomotor(BLDC?), harmonic + planetary gear reducer, Field Oriented vector control (FOC) servomotor is usually close loop control and higher cost than stepper motor 齒槽轉矩 low Cogging torque 齒槽轉矩是永磁電機繞組不通電時永磁體和定子鐵心之間相互作用產生的轉矩，是由永磁體與電樞齒之間相互作用力的切向分量引起的。 Weight 3.7kg Capacity 15kg On Step 0.6 arcsec RMS 0 s some background info stepper vs servo: SimpleFOC simplefoc cn github yaskawa . Amberobotics GYEMS K tech MS9025 ERob Rmb 9600. Btw, RST135 is also using Servomotor