Camping Carabiner 20mm - 55mm

This model has a long history, beginning as a simple clip for USB drives. After some iterations, I redesigned it to follow the design rules of crane hooks. A crane hook is designed as a cross-section with the same tension according to the bending moment. I tried to implement this in my new design to make the Key clip / Carabiner as strong as possible.

This new iteration has a stronger eye portion compared to the original Crane Hook design to make it even stronger.

Best printed in something sturdy like ABS, ASA or PETG, but PLA should also work.

To have more spring tension, you can store the Carabiners “inside out” like in the last picture. Put them back in just before bringing them back into work.

The whole design is parametric, you only need to type in the size in the “Size” field of the attached table in Freecad, and the magic reshapes the whole thing to size. The closing section gets bigger on smaller sizes to keep it printable. The thickness is also adjusted to the size.

Sizes from 20mm to 55mm are attached for your convenience. 

The original Crane Hook Carabiner had a rather thin eye portion, compared to the Hook portion. I corrected this to have now an even stronger Carabiner.