For my Voron 2.4, I wanted some caps at the end of the z rails to prevent the carriages from falling off the rails in a worst-case scenario. For that I printed one of the available models. I wasn't happy with it, because it was bulky, ugly and broke while tightening to the 2020 rail.

This is my own take on an endcap for a linear rail. If you are planning to use this with a warm chamber, consider printing it in ABS or PETG.

For tightening it down, I used a M3x8 SHCS screw with a roll-in nut.