My friend’s daughter has a Stunttracks track toy set. But one of the connectors is relatively fragile, and several have broken. So I want to 3D-printe a replacement. I measured the dimensions with calipers and quickly drew up a prototype.

I printed several draft versions, but none of them were ideal. The upright post is too thin at 3.5 mm, and it is not strong enough in either PLA or PETG. Due to ventilation issues at home, I do not have ABS. This strength issue left me stuck for a while.

Later, I realized I could hollow out this section and use a 3.5 mm 304 stainless steel dowel pin instead. I finally made a version that is even sturdier than the original 😄, while perfectly matching the official dimensions and fitting snugly.

The model is open source here. If needed, you can print it directly. If your printer is precise enough, you don’t need glue. Just press it in firmly.

😄 Enjoy!