Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4487923.

These knobs just can't be torqued enough by hand, but I didn't want to damage them further by using channel locks either, so I designed this custom wrench just for them. Before you print the whole wrench, print the Knob test fit first to make sure the fit is right. You can adjust horizontal hole expansion to tune the fit of the knob. After you get the fit dialed, you can print Ver A4 Perfect.

I used some topology optimization and static analysis because why not.

17cm long from end to end