Thanks for your designs, here is my make of the easy print knife and cap.
The knife blade is held in place with a tiny M2X15mm round head wood screw. After tightening the blade into the holder, the exposed screw thread is cut flush with the handle with a wire cutter. The cap is tight as printed -as noted, likely just needs some light sanding around the handle's edge.
No real post-print work was required, except to clear out the blade mounting slot and enlarge the mount hole slightly for the screw.
Printed fast @50mm/sec as suggested -no problemo.
Definitely a useful tool to add to anyone's toolbox. Thanks again!