I needed a replacement shelf peg, well a bunch of them. It seemed easier to just code in OpenSCAD than to find them in a store somewhere. I started to make this parametric, variables are in place, but it's a work in progress and some of the relationships between pieces needs to be adjusted yet.

Updated: I think it should work now. You can change any size in the *.scad file to get it just how you need it, with the same basic shape.