This is to help with the process of scanning 35mm film on a desk(loading and catching). This model is made for a 1.25" thick desk. If printed at 97% it will be a snug press fit and will not need the added screw. Make sure to not print supports on threads if you are panning to use them. Also with tree supports you might need to slow down the print for the top half. Or maybe other supports would work better? Happy printing and scanning:)