Square Edge drawing tool

This is an OpenScad (customisable) version of the tool here: https://www.thingiverse.com/thing:4186423

The original version had some flaws: the files has some problems, the print needs support, and the tool does not have sharp edges to use it as a rule. These problems are fixed here.

This model can be print without support, "upside down" (text on the bed). I printed my version with a 0.2mm resolution, and it worked well.

Update: 7 Dec. 2020: a thicker version, as requested.