128mm measuring rod

thingiverse

The 128mm-long measuring tool features 0.1mm markings each millimeter, 0.2mm every fifth mm, and 0.3mm on every tenth mm. If you're familiar with openSCAD (tutorial at http://www.makerbot.com/blog/2011/01/19/openscad-basics-the-setup/), you can modify the .scad file and recompile it. It's perfect for assessing your printer's accuracy - simply measure, compare to the actual size, and scale/reprint if needed.