I have an issue on my printer where it will slam into the build plate on the z calibration. The weird thing is that it only hits in the middle back point of all 9 points. I was just wondering if anyone had any ideas what to do, or if it had happened to other people before. The last print I ran worked perfectly and now I can’t get past the calibration. Thanks for any help you may be able to give me. http://ift.tt/2ag4TQN