This is a clamp I designed to hold the PC bed on my ender3v2, one is a knob with a hole for an m4 threaded screw, you'll need to glue it or otherwise secure it in the knob and the other is a knob with a fully printable threaded section.

Creality

Ender-3 v2

No

No

.20mm

40%

Print it with 4 or so walls so the threaded part is strong.