This reduction gearbox is a great way to demonstrate to students how gear ratios compound (it's also just fun to have as a desk toy).
Each compound gear has a 32-tooth and 8-tooth gear stacked resulting in a 4:1 gear ratio. With 9 gears in sequence, the total gear ratio is 262,144:1 and would require around 1,145,320 N to turn the final gear in 1 full rotation.
The design has a crank at both ends of the gearbox, one at the ‘light end’ (spin 262,144 times for a single rotation on the other end) and one at the ‘heavy end’ (you cannot move it).
The design should either screw or snap together easily, if they do not then scale the female parts up by 1% and that should fix the issue.
If you want to remove gears from the gearbox to reduce the ratio, you can replace them with one shim per removed gear and keep the teeth snugly fit. There is also a small notch on the gears so you can colour them in and line them up to see the different gear speeds and travel.
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Print settings:
- 0.2mm layer height
- Supports on the stand and both handles
- 2 walls & 15% infill
Reduction Gearbox (262,144:1 Gear Ratio)
by The Engineering Teacher · original on Printables ↗
Learning / Engineering
♥ 141⬇ 1.0k🖨 7 prints
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Rear Driving Gear.stlDEFAULT
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Driving Gear.stl
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Gear.stl
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Bolt.stl
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Nut.stl
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Stand.stl
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6mm Shim.stl
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12mm Shim.stl
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Handles.stl
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Gear Box.3mf
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