Had a wobbly doorknob so I made a shim so it could be firmly tightened down to the door. Now no more wobble! The flange on my doorknob is 76mm, but it is pretty old so this may or may not fit current standard doorknobs.
Full write up and details on my blog here:
http://makeshiftengineer.com/fix-a-loose-doorknob-with-3d-printing/
| Door_Knob_Collar_v1.stl | 991.6KB |
