Hey @Andrew_M, to do full sheet 49" MDF, personally added an extra 1/2" wiggle room, putting usable 49.5" into https://docs.v1e.com/lowrider/calculator recommended I cut 1440mm Struts (and 1440mm Pipes, however, if anything Pipe should be slightly undersized so Pipe don’t push/warp the plates attached to end braces).
Full disclosure… I’ve yet to cut full sheet MDF, but it’s nice having so much space on my ~2’x4’ usable everyday workbench that I can have multiple smaller projects tiled next to each other.
Am using cheap 3/4" EMT, which has been great. Knowing now how much I’d be using and tinkering with the machine, would’ve invested in thicker wall Pipe, especially for a full width machine. That said, cheap 3/4" EMT was a good choice back then when unsure how interesting this project would be. Am more likely to build another beefier LR3 gantry rather than upgrade my existing 3/4" EMT gantry, but not anytime soon.
Hope that helps!