Custom bicycles can be very expensive due to the manual labour involved when fabricating without tooling. ideas2cycles has developed a process that allows the use of modern materials and joining methods in custom bicycles without the need for expensive tools. The solution is casting metal nodes for joining carbon fiber tubes. The tooling is printed using an industrial 3D printer VX1000 from voxeljet.
There are two reasons why projects such as this one can be implemented: In the first place Antin is a graduate engineer who has required know-how, and secondly he knows about the digital production methods which allow for the cost-effective implementation of putting creative ideas into practice. In this context, Antin bases the concept of the bike frame on a simple but ingenious design, and combines the various frame tubes with exactly calculated sleeves. An magnesium alloy is used for the precision casting parts to save on weight.
The process starts with simulation-based design. Load cases and boundary conditions are defined and topology optimization is performed. The optimal shape is then transferred to a CAD model that contains the tailored dimensions for each customer. The tooling is designed and the casting process is simulated. When the design is ready, the STL files of the tools are sent to a company (Hetitec Oy) for printing. Within a week the tools arrive at the foundry and the casting can be done. Difficulties in casting the metal matrix composite (Al-SiC) material led to a failed first attempt. Changes in the mold design were required, but fortunately the fast lead time of the molds meant that the problems were quickly solved. The successful nodes are post-machined and bonded to carbon fiber tubes. The bike is now ready for a test ride!