I was looking for more accurate vertical angle calibration for my printer, since the included one is so short...but I had no idea how to do it. I found this video (I didn't create it), which has a great solution and the calculation is explained: http://www.youtube.com/watch?v=IP5NF1_ySpo Here is the calculator he used: http://www.csgnetwork.com/righttricalc.html If you use the STL attached, use an A value of 125mm. I printed with .4mm layer heights for speed.