HPR28 Low-Backlash Precision Planetary Gearbox (≤15 arcmin) for 28mm (NEMA 11) Motors

This HPR28 precision planetary gearbox is engineered for 28 mm (NEMA 11) stepper, brushless DC, and servo motors or equivalents. Featuring a space-saving inline design with a built-in input shaft coupling, it accommodates motors with a 5 mm shaft diameter and a maximum shaft length of 10 mm. The gearbox delivers low-backlash gearing (≤15 arcmin for single-stage) with ratios from 4:1 to 200:1, providing 1–6 N·m rated output torque and 90%–96% transmission efficiency. Capable of handling up to 1,000 RPM rated input speed and loads of 100 N radial / 50 N axial, it operates at ≤55 dB with IP54 protection, lifetime lubrication, and a 20,000-hour lifespan. Its compact 35 mm flange and high torque density make it well suited to precision motion axes in desktop 3D printers, small CNC routers, medical and laboratory instruments, automated pick-and-place systems, optical positioning stages, and light-duty robotic joints.

General Specification

• Manufacturer Part Number: HPR28
• Product Type: Precision Planetary Gearbox
• Rated Input Speed: 1,000 RPM
• Max. Input Speed: 2,000 RPM
• Max. Radial Load: 100 N
• Max. Axial Load: 50 N
• Noise: ≤55 dB
• Protection Class: IP54
• Lifespan: 20,000 Hours
• Ambient Temperature: -20° to +150°
• Lubrication Type: Lifetime Lubrication
• Output Shaft Type: D-cut
• Output Shaft Diameter: Φ6 mm
• Output Shaft Length: 20 mm
• Input Shaft Diameter: Φ5 mm
• Input Shaft Length: Max. 10 mm