Door or window alarm switch/magnet holder

prusaprinters

Many older alarm systems use reed-switch/magnet pairs on doors and windows to detect if they are opened - the magnet is normally adjacent to the reed-switch when the door or window is closed. Opening the door/window moves the magnet away which causes the reed-switch to go open-circuit, notifying the alarm system of the change.My house has just such a system, but over the years the original plastic shells have turned that horrible shade of yellow. Rather than buy new shells complete with reed-switch/magnet, I decided to design printable shell replacements to the exact same dimensions, and with the same knock-out sections, as the originals.There's no need to disconnect any wiring - the reed-switch module pops out the original shell and clips right into the replacement, as does the magnet.I recommend using cutters on the original magnet shell to extract the magnet - the magnet is very brittle and can easily break if pried out.The replacement shells have countersunk screw holes in the same place as the originals, so no need to drill new holes in windows or doors.I recommend printing in white PETG as it's less brittle and more resilient to UV light.Note: The OpenSCAD source depends on https://github.com/revarbat/BOSL.git