Gear Box
Senior Project at Cal Poly, San Luis Obispo
Team-based project, including myself and two of my peers
Our team was tasked by Professor Ramanan Sritharan to develop an improved power transmission system for the Mechanical Systems Design course at Cal Poly. The course teaches students how to design and optimize power transmission systems, currently using wooden and 3D-printed components. Our redesigned system features metal gears, machined shafts, and a robust housing to serve as a durable, high-quality demonstration model for future lab sections.
Early Prototype
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The first concept design of the gear box featured a hand crank input for a two parallel gear axis system to achieve gear reduction.​
Early Prototype
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Exploded view of all components in the gear box which features ball bearings, two 70 tooth carbon steel gears, two 18 tooth carbon steel gears and aluminum housing pannels.
Preliminary Design​
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We created this fully functional prototype using accessible materials to validate our design. It includes 3D-printed gears and shafts and flanged ball bearings.
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Result: This prototype demonstrated our design’s feasibility, and enabled us to identify areas for improvement before transitioning to machined metal components in the final version.
Final CAD Design
This second iteration CAD design allowed for easy gearbox disassembly and improved durability. It features adaptable human or electric input with either a hand crank or electric motor to achieve a 0.66 gear ratio.
Manufacturing
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Gearbox
• Contoured aluminum walls using water jet
• Bored holes using a manual mill for bearings
• Powder coated panels
• Press fit bearings
• 3D Printed handle and motor mount
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Wooden Housing
• Table saw using dado cutter for wooden dowels
• Routers and laser cutter to create top and bottom panels
• Coated with polyurethane
Final Product Design
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We developed a higher-quality power transmission system that utilizes metal gears, machined metal shafts, and better housing design. This final model will be used for years to come in future Cal Poly ME 329 labs and other classrooms to demonstrate a hand crank or motor-powered system.