Case Study: Collaborative innovations in high precision CNC machining for Gevenalle

Sherpa’s high precision CNC machine shop worked to develop cyclocross shifter brackets for Gavenalle utilizing the fourth axis to reduce setups and save on manufacturing costs.

Background

Cyclocross is a unique discipline of cycling that combines elements of road cycling, mountain biking, and steeplechase. Gevenalle is a Portland based provider of custom kits for converting road bikes into cyclocross bikes.

Design Challenge

Gevenalle asked Sherpa Design to improve their shifter conversion kits. The objective was to design and manufacture shifter brackets that were not only light, strong, and fast, but also sleek in design. Sherpa had to optimize the design for manufacturing, CNC machining, and align the target pricing for Bill of Materials (BOM).

Sherpa’s design team embarked on the project by creating redesigned CAD models. They specifically focused on enhancing the mechanical robustness of the brackets to withstand harsh cyclocross conditions. From there, our design team created a whole family of parts.

NX CAM simulation of precision CNC machining on shifter brackets for Gevenalle.
NX CAM Simulation of CNC Machining shifter components.

Machining Challenge

With the focus now shifting to prototyping, Sherpa fabricated double-sized prototypes to evaluate the fit and alignment of surfaces. This meticulous approach allowed them to closely examine the functionality and ensure optimal performance of the shifter brackets. Once prototyping validated the design, we moved on to production size fabrication.

High precision CNC machining of finished parts for client Gevenalle.
High precision CNC machining of finished parts.

One major machining challenge arose when we attempted to create an off-angle hole in the shifters with our 4th axis machine. Sherpa developed a custom work holding to secure multiple parts at once to maximize machine throughput. Creating an entirely new setup for each off-angle hole was time-consuming and carried the risk of misalignment. This could result in scrapped parts. Sherpa’s NX CAM Machine Shop team explored innovative approaches for the production phase to resolve this issue.


The solution involved strategically rotating the part placement on the fixture and utilizing the 4th axis. This enabled them to machine the parts and drill the off-angle holes within the same setup. Leveraging NX’s built-in simulation capabilities allowed the programmer to confirm the feasibility of this machining process before commencing production. This helped reduce the time to first good parts. 

Conclusion

The collaboration between Sherpa and Gevenalle culminated in the successful delivery of the final shifter brackets. The machined parts meet their stringent requirements for quality, design, and competitive pricing. Gevenalle took the designs to their overseas contract manufacturers for mass production.  Sherpa handled bridge parts until their manufacturers were up to speed.  Gevenalle’s products are available for purchase on their website as well as in bike shops nationwide.

Gevenalle cyclocross shifter brackets.


Sherpa looks forward to continued collaboration with Gevenalle on upcoming projects and product development initiatives. As a trusted machine shop with deep expertise in high precision machining and design for manufacturing, Sherpa is a reliable partner for clients seeking exceptional CNC design support.

To learn more about Gevenalle and their range of products, please visit their website at Gevenalle.