Gears

Part: Gears

Transformations:	3D Printing, Hobbing, Casting, Injection molding
Tools:	3D printers, Metal lathes, Laser cutters, Plasma cutters, Wire EDM Cutters

Introduction

We need Gear Families that all work with each other. This includes popular construction toys. But we're also scaling stuff up to work with Big Iron, like 40mm and 100mm frames. And rack and pinion.

Challenges

Compatibility with existing gear and sprocket families:

• Meccano/Erector/Vex
• LEGO Technic

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• Bicycle
• Rack (unrolled gear) and pinion

Approaches

Laser Cutter

• Fabrication on laser cutters is common, works well.

CNC mill/router

• Sherline examples
• Taig Mill examples
• Bridgeport examples

Hybrid

Hybrid fabrication; RepRapping and then precise tidying of each layer with a milling/routing head is the most promising.

• Direct: We can make the plastic gear directly
• Mold: We can make the molds for filled epoxy gears. See HandmadeGears.

Hobbing

• Timothy Edward's build of a Meccano Gear Making Machine, technically a gear hobber:

via http://edwards.web.users.btopenworld.com/meccano/modelgear.htm

Wire EDM

Main page: ElectrochemicalPrintedCircuitBoardHead#electric discharge machining

• Forrest Higgs proposed this once.

Casting/Mouldmaking

• We can make molds for Filled epoxy

CNC plasma cutting

2D cuts can be stacked, with through holes for bolts to provide alignment and compression, allowing for the construction of sturdy power transmission components for keyed shafts.

Off the shelf

• PRO Gear Rack, 39" (1 meter) / PRO Rack and Pinion Drive, NEMA 34
• Internal Insert Module 1.0 Gear Rack (0.5 meter) / Module 1.0 Pinion Gear 16 / 20 / 32 / 40 teeth
• Module 1.0 Gear Rack – External (0.5 meter) / Module 1.0 Pinion Gear 16 / 20 / 32 / 40 teeth

References

• RepRap gear design
• Spline and gear mill inserts