About this 3D model
This is the second version. The older version is here: http://www.thingiverse.com/thing:7091 This is a simple piece that forces the extruder to start and stop on short strips. If the strips are clean and the exact same length as the control box, the start and stop calibration of the extruder is good! This version has better control of the test stripe so you can tweak it to one pass of the head, and prints out multiple sets of bars, each at a different length. Slightly related to: http://www.thingiverse.com/thing:8859