Bragi is striving to integrate the most cutting edge manufacturing techniques possible to drive down product weight and cost while driving up performance, reliability and safety.
Everyone is aware of the limitations of traditional manufacturing techniques, whether it's machining, casting, forging, composite layups, etc. A Hubless fan works best being produced as a single piece rather than individual blades for both assembly and maintenance purposes, but isn't conducive to these traditional techniques due to the complexity of the blade geometries and their orientation; not to mention that all metal parts are heavy!
With the lightning fast innovation in the additive manufacturing space, it looks more and more to be the solution. DMLS printing of metal doesn't provide a great surface finish for an aerodynamic surface without significant post processing, and remember, it's heavy! Stereo Lithography provides an unparalleled surface finish, but the resin materials aren't strong enough to withstand long term use in the field. So what's the answer?
Bragi is researching the use of composite 3D printed parts. Companies like Form Labs produce photosensitive resins with different engineering characteristics that could be suitable for composite part manufacturing. Combining the high resolution, surface finish and temperature stability of their High Temp resin with a strong metallic exterior shell, we may have a solution. Previous experiments have shown promise electroplating resin 3D printed parts with a nickel outer layer on top of a copper substrate. This provides great stiffness and abrasion resistance on top of the accuracy and ease of printing the fan rings.
This process could greatly reduce the cost, weight, and complexity of Bragi's fan rings while making them more reliable!
