This is now a full 98" deep and 2" deep. That’s 1" longer than 4x8 sheets, so you don’t have to run your sheet to the edges. It’s best to move a bit away from the edges because nails/screws tend to crumble the MDF.
I want to give it a bit and make sure everything’s working and staying in place before leveling it. It’s pretty level as-is though.
Don’t surface it yet, please. I didn’t because there’s some things to check and tune before doing that. At this point it would just be wasting the new board, and really it’s quite level already.
I will hold off. One of the things I noticed is the verticals for the gantry are not parallel. I think it is causing tension in the frame. I think the gantry needs to made more narrow or widen the x axis running rails.
FYI, unfortunately I left a potential landmine for resurfacing today: one of my brass screws broke off about 1/8” below the surface. Is that a concern for flycutting? It’s a #6 brass screw, I think, and I couldn’t find it again on the board after removing my piece, so it is fairly buried. I believe the coordinates are around X:12, Y:12.
The irony in this case is that I did plan out drill holes for this design, so I could have used less-fragile screws. My failure was not packing better screws. Sigh.