Rodin Wheels hopes to change the way that mountain biking is done by significantly altering the design of bike wheels. Using a patented technology called 3Drsr (Rapid Structural Replication), the company believes that it has overcome some of the time and cost limitations of 3D printing, while achieving some of the same design advantages. They’ve now turned to Kickstarter to finance the implementation of the technology and mass produce their Rodin Wheels.
Rodin Wheels utilizes an original, hollow design, made in a single piece from “aerospace-grade composites”. The material, combined with the lightweight nature, prevents the wheels from experiencing pinch flats, dented rims and eliminates the need for truing, according to the company. In demonstrating their brand of bike wheels for their Kickstarter video, Rodin commissioned Solid Concepts to 3D print prototype models with fused deposition modelling (FDM). The process of laying down material for each wheel took about 32 hours, 36 with sanding and painting, at $3,000 per wheel. Their test rider took the FDM wheels out for a spin, accomplishing all but the most impressive stunts and unable to “go big”, as the company puts it. You can watch the rider perform some more standard riding procedures in the KS video below:
When it comes to actually manufacturing their wheels, the company will be using their own 3Drsr process. Because the technology is intentionally kept somewhat hidden from the public eye, it’s difficult to determine if it uses any additive procedures. The company’s founder, Kirk Jones, sent me this description of 3Drsr, via e-mail:
3Drsr is a series of dramatic reductions in cost, complexity and required equipment floor space while at the same time increasing part production and reliability over what traditionally would be known as Lost Core Molding. The patented 3Drsr production cell with each cycle produces a low melt metal precision inside shape of the hollow structural part you would like to produce, such as the Mountain Bike wheels. At the very same time under extreme temperature and pressure the core from the previous cycle is over-molded with the desired composite material. Integrated in the cell are two 6-axis robots which perform the handling functions. The robot unloads the over-molded part and sends it through a tank filled with a heat transfer fluid that melts out and retrieves the low melt alloy for reuse, leaving a single-piece seamless hollow structural part. This process is automated and fast.
It does sound a bit like a subtractive process and less like additive manufacturing, but the company insists that it is “what comes after 3D printing.” The equipment of 3Drsr, which “costs about twice as much as the large format FDM Printer” and, with it, the Kickstarter claims that it can produce a single wheel “in less than 5 minutes for under $200”.
Though 3Drsr may not be a form of 3D printing, the prototype wheels, alone, are worthy of a story. The FDM wheels complement this laser-sintered bike frame nicely, even if they go some way to demonstrating the limits of 3D printed parts. And limitations such as structural strength are important to consider when using additive manufacturing for any given project. As Jones added in the email:
…we keep hearing about 3D Printed “functional parts” with new materials always being added and new material data sheets being published but the reality is for structural applications failure of the 3D Printed part is far below the materials base properties and occurs at the boundaries along a given layer due to the printing process. For structural parts 3D Printing is a great tool on the front end for form and fit but cannot sustain function so what is the best way to close the gap to producing “real “ parts, I believe it is 3Drsr for single-piece hollow molded structural ones.
Source: Kickstarter
