I saw the gravity knife fidget toys that were popping up and wanted one I could actually use so I designed one. It takes disposable X-ACTO style blades it takes one m2.5x16 shcs and one m3x16 it was designed for a m3 flat head screw but I didn't have any on hand so a shcs works fine too. The latch requires support but nothing else does. If your printer is calibrated it works right of the printer but it will be smoother if you sand the sled a little. The small bushing goes next to the head of the m2.5 screw and the other bushing goes on the other side.  I printed the latch separately so i didn't have supports on anything else and so I could easily do a different color.