My C2 is only a few months old but it hasn't been as stellar a machine as hoped when I decided to upgrade from my New Matter 3D printer. Having heard read some positive reviews and comments online I was hopeful that spending the extra money would assure a smoother print, experience, and better service. Sadly, none of these things have happened yet. Issues with print bed adhesion have been a major headache, a touchscreen that has blacked (or whited whatever the case may be) out on me because if SD card malfunctions, a filament sensor that has never sensed, are just a few of the issues that have plagued me with the use of this machine. Which leads me to some questions I hope this community can help with: 1. Geof from the forums was great in helping with some hints about how to remedy the print adhesion issues. Although his recommendations have helped somewhat i mistakenly purchased and cut a sheet of PEI but now am not certain it is possible to use PEI on the unheated C2 print bed? 2. I'd also like to learn design but don't want to put the time and effort into getting comfortable with a good program that i won't be able to afford to continue working on for more than a little while. I currently have access to the full Autodesk 360 but is only a one year subscription. My understanding is this is one of the more complex design programs. To get into design would it be worth my while to purchase Simplify 3d Now to learn on or should i stick to free apps initially? 3. Is there a way to quickly and inexpensively fix the non working filament sensor? 4. Is it worth investing in, and cost effective to replace the print plate in the C2 with a heated boriscillate one? At Geof's suggestion in another post, I am attaching photos of 3 small pieces i recently printed showing the z-height adjustments I've made as well as one showing the single piece indicating the most recent adjustment (the single piece was at the highest setting and may have been too close since the piece was very difficult to remove). I'd appreciate all feedback on my questions as well as whether or not i should increase the distance from the extruder now by lowering the z-height level of the plate. Thanks for all the help and suggestions shared in these forums, they have been invaluable.