I wanted a knurled thread protector for my airsoft g n, so I took aubenc's Knurled surface finishing library and enone's Airsoft M4 Threaded Flash Hiders and mashed the models together! This ends up being a bit wider than a standard metal knurled thread protector, but it works the same.
Note: Threading is 14MM COUNTER-CLOCKWISE. Meaning you screw it "tight" to the left and "loose" to the right. Airsoft g ns and real g ns are generally threaded this way. To print this as a right hand "clockwise" thread, you just need to mirror the model - as such, I've included the master Blender file.
Note: I don't know where to mark it in the upload, but this is a WIP.
I made this a long time ago, and while it's fairly simple and scrapped together from other uploads, I still can't get these to thread on right. While the threading IS- 14mmx1, 3D printers seem to generally struggle with threads this tight, so you end up re-tapping the threads once you put this on. In effect, the threads will slowly tear out of the thread protector over time. Just figured this would be a good note for people since this is still getting the occasional view/collect.
This is meant to be printed with PLA, though PETG should also take the print just fine. Presently untested with ABS and all other filaments because my Anet doesn't handle those well.