This thing allows you to raise the position of your Z-axis end stop switch, allowing you to add longer nozzles, hotends, etc. without having to change the height of your bed and therefore relevel and/or change the tension of the springs.
6/23/18: Tested working on Creality Ender 3 printers.
6/23/18: Added 10mm spacer which adapts the shorter design to work with volcano-style heat block setups. Just press it on to the X-gantry bracket above the Z-endstop switch.
6/23/18: Added taller version for use only with volcano heatblock setups (or you can use the original design with the 10mm spacer mounted to the x gantry, if you plan to switch back and forth).
Print these parts in the orientation provided in the STLs.
I found the idea for this design as thing #2531282. After two days of printing that one and having parts that would not fit together I decided to give up and start from scratch with a redesign that prints better, yielding parts that fit together.
Print these parts in the orientation provided in the STLs. This will print without supports but depending on how well your printer bridges there may be some stringing inside the slot where the adjustment wheel goes (see pics). Just trim that away and/or use a file to smooth that upper surface out a bit.
You'll need a 30mm M3 machine screw and two M3 nuts along with the stock hardware for mounting the Z-axis end stop switch PCB. Study the pics for assembly hints.