A parametric FreeCAD model, within the spreadsheet there are 3 simple parameters:

1. Width - set the width of the nylon strap you wish to make a buckle for
2. EndThickness - set the thickness of the material on either side of the strap
3. Depth - for how deep the buckle is; the bigger the depth, the more the strap has to bend around the centre pin so don't set this too high

The number of gripping “teeth” on the underside of the buckle will be automatically adjusted to fit.

The buckle can be printed flat on the bed without any supports and is best printed in a strong material. I use Prusament PETG and it stands up to everyday use.

Included are 25mm and 38mm STLs at “default” settings for quick printing.