First metal 3D printed bicycle frame manufactured
Renishaw, the UK's only manufacturer of metal based additive manufacturing machines, has collaborated with Empire Cycles, a British bicycle company, to create the world's first 3D-printed metal bike frame.
Empire designed the mountain bike to be stronger and lighter by using a process called topological optimization and employing Renishaw's AM250 additive manufacturing system.
The additive process offers design, construction, and performance advantages that include: blending complex shapes or hollow structures with internal strengthening features, flexibility to make design improvements right up to the start of production and the convenience of making one off parts as easily as batches, which allows for customization. The new titanium-alloy frame, about 33 percent lighter than the original, was manufactured in sections and bonded together.
After successful production of the bike's seat post bracket, improvement of the whole frame became a new goal. Empire started with a full-size 3D-printed replica of its current aluminum alloy bike and the frame was sectioned into parts that could be formed in the AM250's 12-in. build height. With guidance from Renishaw, an optimized design was created using topological optimization that eliminates many of the downward-facing surfaces that require wasteful support structures.
Topological optimization software programs use iterative steps and finite element analysis to determine the logical material placement. Material is removed from areas of low stress until a design optimized for load bearing is created, resulting in a model that is light and strong. Historical challenges in manufacturing these computer generated shapes are overcome through the additive manufacturing process.
The AM250 uses a high-power fiber laser to produce fully dense metal parts direct from 3D CAD data. Parts are built layer by layer, in thicknesses ranging from 20 to 100µm, using a range of fine metal powders melted in a tightly controlled atmosphere. A fully welded vacuum chamber and ultra-low oxygen content in the build atmosphere allow processing of reactive materials, including titanium and aluminum.
Mr Chris Williams MD at Empire Cycles said that "There are lighter carbon fiber bikes available, but the durability of carbon fiber can't compare to a metal bike. When you start chucking yourself down a mountain, you risk damaging the frame. We over-engineer our bikes to ensure there are no warranty claims."
Source – Renishaw.com