For this project, I wanted to create my own high-quality composite skis inspired by Fischer Jib skates, twin-tipped park skis with a super short length that I'd always wanted but could never find. I had originally wanted to make a full-length pair; however, I had to work with the constraints of the CNC router. I designed and manufactured a pair from scratch using aerospace-grade materials and numerous steps.

I measured nearly 10 different pairs of cross-country skis to understand important parameters like camber profiles, length and width tapers, and tip curvature. Using Fusion360, I went through multiple complete redesigns as I learned more about ski geometry and manufacturing constraints.

Through research of publicly available manufacturer data and analysis of broken skis, I determined the optimal material stack-up. Salomon S/lab uses a nomex core, wood sidewalls, and a carbon topsheet, while Fischer uses their own proprietary core design.

Fischer uses a presumably in-house core

Unlike downhill skis that use sandwich construction with pressed camber, cross-country skis require pre-cut camber profiles due to their extreme flex characteristics. I decided to use a nomex core with carbon fiber sidewalls and a fiberglass topsheet. The tips would be 3D printed separately due to router size limitations and their tapered geometry.

I couldn't source nomex thick enough for the full ski height, so I stacked two cuts together, bonding them with resin and fiberglass. The fiberglass topsheet was chosen over carbon to showcase the internal structure. I had just enough material for three blanks, perfect for having one sacrificial prototype to learn from.

Using carpet tape for work-holding, I routed the ski profiles from the composite stack-up.

The first blank experienced some chatter that thinned the tips, but I corrected this in subsequent pieces by adjusting tab positions and fixturing. Between machining and topsheet application, I spent 3-4 hours hand-picking nomex material from the honeycomb cells for both aesthetics and proper resin adhesion.

I attached the 3D printed ASA tips first.

Next came the titanal binding plate for secure mounting hardware.

For the topsheet, I used vacuum bag lamination which was critical for proper sidewall conformity. The custom jig kept the ski elevated so the topsheet could flow down the sides and slightly underneath.

After curing, I trimmed excess material with an oscillating multitool and sanded everything flush.

Next I applied the base. I wanted to make sure that the fiberglass was easily visible, so for this portion I added black dye to the resin.

It wasn’t pictured but this is also where I implanted a programmable NFC tag at the front of each ski, between the base and the core. The purpose of this was to be able to store data relating to the ski, like wax history.

After it cured

At this point there were 2 ways of cutting off the excess material. Fischer skis have sides of the base flush with their sidewalls, whereas Salomon stick out approximately 1mm. This is for added stability in cornering and skiing in icy conditions. I went with the Salomon route as that’s what I’m used to. I made a 1mm spacer for the cutting tool. I then finished the sides with a scalpel blade to remove any thin plastic shavings still attached.

After trimming the excess base material

Next I had to flatten and grind the base. I reached out to a local place called Starthaus (https://www.starthaus.com/) and they let me come in and use their equipment to prep my bases.

After a couple passes, the darker sections are where it is removing material.

We continued until it was evenly ground, and then gave it a final universal grind pass (not pictured).

I then had to make the center groove. I made my own self-centering attachment for the router. This part was very nerve-wracking, as the depth could only be around 0.5mm, and any minor variance would be incredibly easy to notice.

I ended up throwing on a ring of PTFE around the cutting bit at the last second to reduce friction. This and spraying water onto the surface helped to keep the hand router moving smoothly across the ski.

Moving on to the bindings. I didn’t like the look of the metal pieces on the binding plate, so I used some gun blue to darken the metal.

I drilled out the hole pattern and put the bindings on (in the kitchen because I was running out of time…)

Finally, I waxed and scraped the skis with alternating coats of BP88 and BP99 to saturate the base material, finally finishing it off with a layer of Briko LP2 orange.

That morning, me and my team hiked up to one of the few remaining places that still had snow, Castle Peak.

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MD 2023