128mm measuring rod
by GoffinGuy, published
It is a 128mm long rod with 0.1mm notches every mm, 0.2mm notches on every 5th mm, and 0.3mm notches on every 10th mm. If you know openSCAD, (tutorial at http://www.makerbot.com/blog/2011/01/19/openscad-basics-the-setup/) then you can edit the .scad and recompile. Its great for testing the accuracy of your printer!
Print. Measure. If the rod is the wrong size, scale and reprint.