Modules

Every module on this page exists because buying it turned out to be blocked. Rarely because the thing does not exist usually because it is sold only to businesses ordering hundreds, or arrives undocumented and needs weeks of work before it runs, or comes locked inside a system we are not allowed to modify.

Chapter 7 explain the barriers. These pages document our attempt to get past them.

Each module is documented so that someone else can build it without talking to us: what it does, what it weighs, what it cost, what interfaces it exposes, what failed, and how to reproduce it.

Corner Module

Hub motor, disc brake, and suspension fork as a single self-contained corner unit. Lets us change vehicle topology without redesigning the drivetrain.

Steer-by-Wire

Capstan-and-cable steering with a mechanical brake line, decoupling the steering column from the chassis so the corner module drops into almost any frame.

Open FOC Firmware

Firmware for ~30 CHF MKS Odrive clone field-oriented control boards, tuned for e-bike hub motors.

Battery Pack

15S3P LiFePO4, 2.88 kWh, built cell-up with bolted bus bars. Serviceable at cell level, designed to outlive the prototype it was built for.

CAN Commodo

Handlebar controls and throttle over CAN. One bus, one connector, arbitrary number of inputs.

Pedal-by-Wire Generator

Chainless pedal generation. Makes assistance level a software parameter instead of a mechanical one.

Design rules

Every module here is held to the same standard, taken directly from Making It Viable and Living Within Limits:

• Reproducible — commodity parts, published BOM, no unobtainable components
• Serviceable — repairable in the field with common tools, at the level of the part that failed
• Instrumentable — open protocols, logged data, no black boxes we cannot measure
• Reusable — designed to survive across prototype generations rather than be discarded with the chassis
• Documented — mass, cost, and interfaces published, including when the numbers are unflattering