Door Knob Lever Adapter

Recently, a friend of mine both broke of his wrists in a bicycle crash. On his first day home, someone came to the door while he was alone and he realized that he couldn't actually open the front door- or any other doors in apartment if they had been closed.

I took photos of the four different styles of knob in his apartment and printed up these levers. they weren't designed to be svelte, they were designed to be opened with a cast or a knee or whatever he could, so they are big, clunky, and have ends that are easy to hook onto for leverage.

I've included stl files of the knob shapes that I used as the boolean tool for each of the handle styles, in case that helps. The BaseHandle shapes fit no particular knobs, but you can model and cut your own door knob shape out of them if you like.

Here are the rough diameters of the different style knobs. They're all pretty similar, which makes me think that there's some kind of standard, and I'm just bad at measuring:

Ball: ~47.6