LEG0 compatable Technic Pins. Print with PETG for more strengths and longevity. 

Please read:

!After the print finishes let the print bed cool down. as I've found this helps the layers adhere better!

If you remove them from the bed while it's still warm, I've found that the pins may crack or break.

Ensure your print bed has solid bed adhesion, or the pins may come loose during printing.

Or use the “With Brim” print profile.

DISCLAIMER: LEG0 is very precise and hard to 3D print. Different filaments may yield different results.