The Indie Project is an e-bike concept based on sheet metal structures.
The Indie is an open source vehicle concept based on sheet metal. The design is freely distributed and can be modified by anyone familiar to CAD. The idea is to utilize sheet metal in a panel structure instead of a tradition truss construction using tubes. Main advantages are simplicity, ease of manufacturing, assembly without jigs or advanced machinery, low skill level required and no heat input needed. The main drawback is added weight, but in the case of an e-bike with heavy batteries and motor the disadvantage is not significant. The required parts can be ordered from most modern sheet metal shops and assembled in one evening using a few cheap tools.
The frame consists of 23 sheet metal parts that are joined using adhesive bonding. Blind rivets are used for alignment and pressure during bonding. The sheet metal parts can be cut using a 2D laser or water-jet cutter and folded using simple tools. Most of the bends are 90 degrees. The prototype frame is made from 1,5 mm aluminium alloy and it weighs 3,5 kg. Thinner material will result in weight savings. However, more complicated stiffeners are required in places where buckling is an issue. The structure would be more efficient if it were more of a shell type construction, but we wanted to keep it as an open sandwich/stiffened panel solution.
Acknowledgements: We wish to thank SBA Components, SolidWorks Corp, Novelis and 3M Finland for supporting this project and Simon Lessels for giving the inspiration for this concept.
The Indie bike won an award in the biennial Plootu Fennica sheet metal design contest.