Carriage bolt thumb head (imperial)

This is a thumb screw cap for a carriage bolt. Lots of people have made knobs that go on a hex screw or bolt, but it's sometimes hard to find a large hex bolt. This is for those times when you have to go to the big box store and get a carriage bolt.

The sizes are for the US carriage bolts: ["#10", "1/4", "5/16", "3/8", "7/16", "1/2", "5/8", "3/4", "7/8", "1"].

I included short&knurl=12 caps, and tall&knurl=50 caps, for sizes #10 thru 3/4".

The naming convention for a file named 5.8-h18k12f1.05.stl would indicate "for a 5/8" bolt, with a cap height of 18mm, 12 knurls, and an expansion factor of 1.05 to account for tolerances and plastic shrinkage."

The size has been engraved on the bottom (non-seen) side.

Customizer can customize: size, knurls, height.
If you download the file and run it through OpenSCAD, there are functions for rendering a carriage bolt, a carriage bolt cutout. Things like the diameter and font can easily be changed.

Comment if you notice any features or bugs that i didn't. e.g. chamfers, metric, bolts etc.