I am looking at buying a 3d printer and although i like getting quality, my budget will not accommodate. I have read many posts on here about what to do as a noob, but as these things are improving all the time as technology improves, I am left with a few questions. 1. How important is bed levelling, ie after you do it once, do you have to keep doing it. Reason, i have seen a couple of printers, http://www.aliexpress.com/item/Updated-Big-size-220-220-240mm-High-Quality-Precision-Reprap-Prusa-i3-DIY-3d-Printer-kit/32604869871.html?spm=2114.13010308.0.49.FIAEJg The newer one does not have auto levelling, but the older one does. 2. what is the most common file type used for these? I don't mind that it is a self build and I understand that a box for it is advantageous and I can build that. Any advise would be appreciated.