The file 'Printable Square Ruler With Guide And Cutout (try Square) 3D Printer Model' is (scad,stl) file type, size is 4.7KB.
Just a simple square ruler with guide and cutout in the corner, so it can be easily used for marking metal or wooden parts (see first photo).
In German such a thingy is called: Schlosserwinkel. I just learned from yvans comment below that in english this is called try square. The second photo shows both the printed ruler and the original metal ruler which inspired the design.
The guide can be used to align the ruler with the edge of the work piece. At the base of the guide there is a small groove, so the guide aligns well with the edge of the work piece. Additionally, there is a cutout in the corner of the ruler, so it aligns well when measuring against two sides of the work piece (for measuring right angle).
Well, just after publishing, I noted
http://www.thingiverse.com/thing:143605
which has been published only a few days ago and which I hereby give the link to. However, I created my scad code from scratch using the existing metal square as inspiration.
square_ruler.scad | 4.2KB | |
square_ruler_50x50.stl | 8.3KB | |
square_ruler_50x50_mirrored.stl | 8.5KB | |
square_ruler_70x50.stl | 8.3KB | |
square_ruler_70x50_mirrored.stl | 8.5KB |