Big models calibration
thingiverse
This file will help you to calibrate big models like my other thing: http://www.thingiverse.com/thing:2288841 It is a 210 x 210 mm piece. It has curves so in case the z-offset is not well calibrated the curves won't be made correctly. Try to adjust the z-offset and in case the bed is a bit tilted, adjust it (add paper or something).
Download Model from thingiverse
With this file you will be able to print Big models calibration with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Big models calibration.