Orbital Gearbox

A prototype gearbox design that combines planetary and strain wave gearing to create a multi-material 3D printed reduction drive that is compact while providing very high gear ratios for high torque applications.

If you would like to support this project you can boost this model to help fund further development and testing. Any support is greatly appreciated!

Features

• High positional accuracy with virtually zero backlash
• Two-speed compound gearbox design
  • Capable of being driven by either the sun gear or planet carrier
• Modular design made for 3D printing and easy assembly
  • Quickly experiment with new materials and processes
• Custom print profile and STEP files for accurate functional prints
  • Build plates separated by component and material capability

Specifications

• Planetary gearing with ratio of 4:1
  • 32 tooth sun gear, planet gears offset by +/- 2 teeth
• Strain wave gearing with ratio of 40:1
  • 80 tooth flex spline, 82 tooth ring gear
  • 2 mm flex spline wall thickness
• Integrated 2 degree planetary gear bevel allows flex spline to bend more naturally
• Outer dimensions: 74 mm x 100 mm x 100 mm
  • Housing can be mounted with eight M3 screws (49mm radius)

Assembly

Printed Parts

• Planetary Gears
  • SunGear.step (1x)
  • SunGearPost.step (1x)
  • MajorPlanetGear.step (2x)
  • MinorPlanetGear.step (2x)
  • CarrierFront.step (1x)
  • CarrierBack.step (1x)
  • CarrierSpacerFront.step (1x)
  • CarrierSpacerBack.step (1x)
• Flex spline
  • FlexSpline.step (1x)
  • FlexSplineCore.step (1x)
  • FlexSplineCap.step (1x)
• Housing
  • HousingBody.step (1x)
  • HousingCover.step (1x)

Hardware

• M3x16mm Socket Head Cap Screw (1 pcs)
• M3x20mm Socket Head Cap Screw (6 pcs)
• M3x35mm Socket Head Cap Screw (12 pcs)
• MR106-2RS Deep Groove Ball Bearings 6mm x 10mm x 3mm (8 pcs)
• 608-2RS Ball Bearings 8mm x 22mm x 7mm (2 pcs)
• 6806-2RS Deep Groove Ball Bearings 30mm x 42mm x 7mm (1 pcs)
• 6812-2RS Deep Groove Ball Bearings 60mm x 78mm x 10mm (2 pcs)

Instructions