First of all, I am new to all this 3D printing business and just got a Robo R2 for xmas. I was able to print with the included red PLA filament without issues and was actually pretty satisfied with the quality I got. Then I bought some generic ABS filament from amazon just to experiment (bought a few different brands, none of which was Robo) and tried to print with it but the filament would not stick at all. I even tried buying Buildtack and using it but although the filament now stick somewhat, it would always end up getting loose from the bed at some point and I had to abort the print. I have some questions about this: 1 - In general terms, would I have better success with Robo-branded ABS? It is almost double the price compared to the ones I bought. 2 - Is loading a generic ABS filament in the printer as "Robo ABS" ok? Should I create different profiles for different ABS brands? If so, based on what? 3 - Is there anything I am missing that would help getting ABS to stick to the bed? On a tangentially related note, I could not find replacement PEI sheets for the R2 on Robo's site (I was looking just out of curiosity. Not that I think that I need one now). If I ever need one, are they generic so I can buy it anywhere (taking into account the bed dimensions, of course). Also, should I remove the PEI sheet if I want to use Buildtak (because I just applied it over the PEI sheet)? Thanks in advance.