I have only published the parts I've modified please download the original design for additional parts. The screws required are around 160mm for vertical and 60mm for horizontal should be sufficient.   I printed it with a 26% infill and with a 2mm shell so the X beams are just about solid.I also cut 2mm off the bottom when printing in with cura and its strong enough but I left it thick so you can decide. Print time with above settings and at 50mm/s 0.25mm LH was about 4 hours.   I used a M5 threaded rod for the larger screw as I couldn't find M3 in the required length the bottom nut is a nylock nut to keep it inplace at the top I have a standard nut and a wingnut adjusted to remove all slack and then tightened together, the adjustment is smooth actually much better than I anticipated.