Pilot Carbon Fiber Stitching Robot

Date: October 30, 2018

Company: Seriforge

I joined Seriforge as they were designing their second generation carbon fiber stitching robot. Seriforge was working to automate the production of high volume carbon fiber parts, by creating a robot capable of stitching thick layers of carbon fiber fabric with carbon fiber tow (thread). This could then create complicated, 3 dimensional, dry carbon pre-forms which could be easily handled, and later added to a mold and cured with epoxy. The stitches also increased the interlayer strength of the final molded part.

There were considerable challenges around stitching through thick (up to 1in) layers of carbon fiber plys. My role on the team was as a mechanical engineer and system architect. I worked closely with the 2 other ME's, as well as our EE and Software team to ensure the system came together quickly. I designed our Safety system (Safety PLC w multiple E-Stops, door sensors, and sensor inputs), welded + Bosch extrusion machine frame, X-Y Gantry for positioning parts (with an outside vendor), and assisted heavily in the design of our electrical cables as well as electrical layout (including panels). I also tuned the servo motors on the system, and assisted in a few small mechatronic designs that employed retro-reflective fiber optic sensors from Keyence.

The first "Pilot" machine we built came together within a year of conception, stitching customer parts. We battled a few challenges, namely reliably stitching without bending needle tips, or losing the fiber tow from the needle (at times we were only getting 10 successful stitches before running into issues). Early on I helped restrain the team from trying to tackle these issues with a shotgun approach, rather taking the time to identify the root causes of our issues (via brainstorms and design of experiments). We were able to identify the major contributors to our issues, and try small iterations on our design on a test bench setup. Within a month (with a few new rounds of CNC parts) we had our system stitching reliably, able to perform 100s of stitches without any errors or faults.

This was a fantastic project to work on. We had a fantastic team dynamic, and accomplished remarkable tasks in short time frames. I felt privileged to contribute to an amazing team effort.

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