I had noticed that there were not a lot of realistic pocket knife options out there, so I ended up CADing one. It turned out better than I had anticipated. It comes with a locking mechanism and two notches. One makes it so you can open the knife with your finger and wrist. The second notch makes it so you can open the knife by drawing it out of your pocket. And like all pocket knives, it comes with a pocket clip. If you happen to be left-handed, mirror the handle in Slic3r (Prusa Slicer) along the Z-axis. Remember, this is a 3D PRINTED KNIFE, so don't expect it to work like a real one. This is a work in progress so if you have any suggestions on improving it, please let me know by writing a comment. Enjoy!

Print Details: 

Here are two things I should mention:

1. Print the knife blade vertically. It makes it look a lot better. 
2. You will have to split the STL file into multiple objects to print the knife blade.

Note: The entire knife blade assembly shown in the pictures was printed on a Prusa MK3S+ using a 0.4mm nozzle diameter and PLA, at a layer height of 0.1mm. Ideally, PETG will probably work better.

Assembly Instructions:

1. Insert the knife blade into the handle
2. Insert the round connector piece
3. Take the hexagonal connector piece and insert it into the round connector piece
4. You will most likely need a hammer to tap the pieces together lightly

And you're done!

Happy Printing!