HF-KP13 New Original Mitsubishi AC Servo Motor HFKP13

The Mitsubishi HF-KP13 sits at the compact end of the MELSERVO-J3 HF-KP series — a 100W AC brushless servo motor designed for applications where installation space is tight, response demands are high, and the load is light enough that a small, direct-coupled motor handles the job without a gearbox.

At just 40×40mm flange size, the HF-KP13 occupies roughly the footprint of a domestic electrical outlet, yet it produces 0.32Nm of rated torque and can accelerate smoothly to 6,000rpm at maximum speed.

• Low Inertia Rotor: Lightweight rotor (0.088 kg*cm²) enables quick acceleration and deceleration for shorter cycle times
• 18-Bit Absolute Encoder: Provides 262,144 pulses per revolution for precise position control without homing procedures
• Natural Cooling: Self-cooling design eliminates fan noise and maintenance requirements
• IP65 Protection: Dust-tight and protected against water jets for harsh industrial environments
• Compact Design: Minimal footprint ideal for space-constrained applications

The HF-KP13 is commonly used in:

• Belt-driven positioning stages on assembly automation lines
• Direct-drive paper feed mechanisms on cutting machines
• Multi-axis robot joint drives in SCARA-type light robots
• X-Y stages on semiconductor inspection equipment
• Feed axes on industrial sewing and embroidery machines
• Automatic insertion head drives on electronics PCB assembly equipment
• Tool indexing axes on small CNC machining centres and engravers

The HF-KP13 pairs with the MR-J3-10A (analogue/pulse interface) or MR-J3-10B (SSCNET III network interface) servo amplifier. The MR-J3 amplifier reads the motor's absolute encoder via dedicated encoder cable and provides battery backup to retain position across power cycles.

Without an EM brake, the axis is held by the servo loop's position control while the amplifier is energised. When the servo is disabled, the axis is not mechanically held. For horizontal axes where gravity does not act on the load, this is usually acceptable. For vertical or inclined axes, the brake variant HF-KP13B is recommended.

The ratio limit means the total load inertia seen at the motor shaft should not exceed 15 times the motor's own rotor inertia (0.088 kg*cm² × 15 = 1.32 kg*cm² maximum). Exceeding this ratio makes the control system difficult to tune and can lead to overshooting and oscillation.

The maximum speed of 6,000 rpm is an intermittent peak rating — the motor can reach this speed but should not sustain it indefinitely. Continuous operation is rated at 3,000 rpm. For high-speed sustained operation, verify the torque-speed characteristic at the operating speed.

The MR-J3 amplifier contains a battery that backs up the encoder's position data. Mitsubishi recommends replacing this battery every 3 years. If the battery depletes completely, the encoder position data is lost and requires a homing procedure on the next power-up.

The HF-KP series was designed for the MR-J3 amplifier generation. Direct plug-in compatibility with MR-J4/MR-J5 amplifiers should be confirmed against Mitsubishi's compatibility documentation. For system upgrades, upgrading to the corresponding motor series (HG-KR for J4/J5) is often recommended.