Here are some 3D design STL files that can be downloaded and printed.
N Scale Weight Ruler
This ruler shows the NMRA recommended car weight in Ounces and Grams based on the car length. Just insert the wheels in the track and align one end of the car body with the starting line of the ruler. The target weight will be aligned with the other end of the car body.
Linear Switch Machine Drill Templates Version 2 for Atlas Code 55 Turnouts
These drill templates are for use with N3IX Engineering Linear Switch Machines and Atlas Code 55 N Scale Turnouts. The goal was to minimize the time spent underneath the layout when installing the switch machines. To use the template, align it with the desired turnout endpoints on top of the layout and then drill the hole for the throw wire and the pilot holes for the mounting screws. Mount the Switch Machine below the layout and fill the mounting screw pilot holes as desired.
Four separate templates are provided for mounting the switch machine on #5 and #7 turnouts on either side of the track. In addition the #5 templates have 2 sets of mounting screw pilot holes to allow the switch machine to be installed on either the facing point or trailing point side of the throwbar.
The drill templates have been updated with taller and stiffer drill guides to better keep the drill bit vertical. I also removed a short length of the center rib at each end so that the template can be easily secured with pushpins.