Ski Racing Arm Guards — Forearm Protection for GS

Body protection gear is extremely expensive in ski racing so I tried making my own arm guards. Designed to be 3D-printable without supports. Sized for adults but probably can be scaled down to fit a kid.

Yes, they broke…

… but they do work! Let me clarify and tell you the whole story so you can make your own (and even better) so they don't break.

Printing

• You have to print using ABS, ASA or nylon, maybe hard TPU. PETG and PLA definitely wouldn't work, don't waste your filament.
• I used Creality K1, 0.6 nozzle, 0.36 layer height using eSUN ABS. It was quite wet as you can see but I didn't have time to dry it. I couldn't get the same layer adhesion from ABS as I did with Eryone ASA so next time I'll try to print again using ASA or other materials I mentioned.
• After printing let the print cool slowly in the chamber to maximize strength.
• I used a brim to make sure it stays attached firmly to the bed.
• Punch through or cut the one-layer supports that cover the holes for straps.

Materials

1. Straps (20-30mm), about 2 meters, non-stretch, or whatever you prefer
2. Velcro, same width as a strap, about 0.8 meters
3. EVA foam of 2-4mm thickness and double-sided tape to attach it, or use foam that comes with adhesive already. It can be bought in stationery/art shops.
4. A couple small pieces of synthetic fabric (see step 5 below & last pic in the gallery)

Building

1. Print the guards, one normal and one mirrored (easy to do via a slicer)
2. Sew the velcro and the straps together. Look at some shin and arm guards online to see how they are strapped on.
3. Attach the EVA foam.
4. Attach velcro straps to the guard
5. I didn't do it but I highly recommend you to make some kind of fabric pouch that goes on the front of the guard, like on the last pic I attached (or look for Shred and POC arm guards for examples). In case the gate goes under the guard in the front (that's how mine broke), it would only pull the fabric and not the plastic so it shouldn't break — and the gate shouldn't get too far beneath the guard anyway, so make sure to attach the straps as close to the end as possible.

Usage

I made some mistakes while using them so they broke. They broke because the front of the guard came out of the glove and hit the gate. Generally speaking the front part shouldn't really be in contact with the gate, I learned it later. But in case it does, it should be under the glove to make sure the gate doesn't get caught inside and pull your arm. Mine broke when that happened so I can even say they saved my arms from potential injury this way. 

I hit some gates head-on, completely perpendicular like with a shield (for testing), the guard survived those hits without issues and my arm barely felt anything. For next time I'll probably even make them thinner, 4mm is a bit overkill. I'll upload the new files when/if they are ready. However usually the hits are sliding, not direct, which even a tiny bit of plastic should be able to handle with ease. 

If you need the Fusion360 files, let me know, I'll upload them.