Belt sander angle gauges (configurable in OpenSCAD)

I use a 1" x 30" belt sander to grind high-speed steel lathe tools. These tools need to be ground to various angles to work properly, although the angles don't have to be too precise - "close enough" is good enough.

I don't want to put my precision measuring tools anywhere near grinding tools, so I designed these gauges to allow me to set the angle of the tool's table quickly and easily. They are accurate enough for my needs (they are actually quite accurate).

Note that the default angle between the belt and the table is 90 degrees - the angles shown on these gauges are relative to that. For example, if I want to grind a 3 degree angle on a piece of tool steel, I use the "3" gauge to set the angle between the belt and table at 93 degrees. This results in a 3 degree slope on the square-section tool steel - hopefully the picture explains it!

I have included STL files for 5 different angles, but any angle can be selected by making a simple change in the OpenSCAD code and recompiling it. However, larger angles will result in the right-hand side being clipped to prevent it getting too long (the 30-degree gauge gauge was photographed before the clipping was included in the OpenSCAD code).