There aren't many robust or cheap lever handle child proofing options. This solution prints a new knob with captive rotating cover for "Design House" brand lever handles. These have a 10 sided stem that the handle attaches to with a set screw. With lever removed, child lock knob can be installed. I used 2 longer set screws for installation.
Category: HouseholdThe author marked this model as their own original creation. Imported from Thingiverse.