pedal_generator_gearbox

Pedal-generator gearbox exploration for the ProjectNeoDrive pedal-by-wire concept.

Goal

This project is used to find a decent gearbox configuration for a pedal generator that:

• is cheap
• stays reasonably backdrivable,
• minimizes wear,
• keeps efficiency acceptable,
• and works with a BLDC motor around Kv=100 (the motor class we already have in stock).

The current script searches valid gear train combinations and ranks them with a weighted score (backdrivability, wear, efficiency, and stage count/cost), then plots expected regen efficiency over pedal RPM and battery SOC.

Main script

• gear.py

Run:

python3 gear.py

Outputs include:

• ranked gearbox candidates,
• best_match_efficiency_map.png,
• best_match_efficiency_map_kv_compare.png.

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Sourcing links (initial shortlist)

Note: AliExpress listings can change over time (title, specs, stock, URL behavior).

BLDC motor candidates

• https://de.aliexpress.com/item/1005009622680232.html
• https://de.aliexpress.com/item/1005010776963168.html
• https://de.aliexpress.com/item/1005010041210790.html
• https://de.aliexpress.com/item/1005011728500156.html
• https://de.aliexpress.com/item/1005008043040484.html

Gear candidates (module 1 steel spur gears)

• 70T: https://de.aliexpress.com/item/1005004090227296.html
• 60T: https://de.aliexpress.com/item/1005004090213302.html
• 38T: https://de.aliexpress.com/item/1005004090075755.html
• 25T: https://de.aliexpress.com/item/1005004089851114.html
• 21T: https://de.aliexpress.com/item/1005004089721227.html
• 18T: https://de.aliexpress.com/item/1005004089640535.html
• 12T: https://de.aliexpress.com/item/1005004088412911.html

Full pedal + gearbox / pedal assembly candidates

• Foot pedal + reduction gearbox assembly: https://de.aliexpress.com/item/1005004857033022.html
• BMX crank + pedal set (mechanical pedal source): https://de.aliexpress.com/item/1005007805733704.html
• Bicycle pedal set: https://de.aliexpress.com/item/1005001871077322.html

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