So, in addition to working on my resin printer (which I really need to get moving on), I've been thinking about making a new FDM style printer to replace my QUBD Two-Up. It was/is my first printer, and has served me pretty well in learning the ins and outs of 3D printing, but it's showing its limitations in speed, quality, and build size. I've done a number of mods to it to make it much more reliable and consistent (Bulldog XL extruder, E3D v6 Lite hot end, various mechanical improvements), but it's still not enough. The replacement for it must be accurate, and faster than what I'm running now (~45mm/sec). I know that the usual rule of thumb is to not use lead screws in this application because they usually aren't fast enough, but I figure with the belt reduction plates for the C-Beam (which have been pulled since their initial release) and changing the ratio from 2:1 to 1:2, the lead screws will be plenty fast enough. Couple that with a 24v power supply running the show, and it should be able to throw around a direct drive extruder accurately at a pretty good clip. I was looking at building a C-Bot, which would get me the build volume I'm looking for (12"x12"x12", give or take), but I've been having issues printing the parts in ABS. I can print well enough in PLA, and I guess I could print the parts in ABS once the C-Bot was built. Part of me wants something that I can just bolt together with minimal fabrication. I have a design that will do just that, with only the extruder mount and the build plate needing to be fabricated (both very simple parts). The design is a lot like most printers with a moving print bed on the Y, similar to the typical Prusa i3 design. The X-axis C-Beam will be bolted to C-Beams on the Z (all 500mm units). Initially I was going to use two full C-Beams on the Z, but I have been thinking about using just one. It saves me about $70 (not huge in the grand scheme of things, but it's still $70), but I'm not sure if I will suffer sag on the X-axis as a result. If the wheels are properly preloaded on each gantry plate, then sag should be virtually non-existent, at least in my head, but I wanted to get your thoughts before committing to it. At least with this setup I can add the parts as necessary to add the lead screw back in if I see problems. Thoughts?