inspired by https://www.materialise.com/en/hands-free-door-opener,
(Edit: found it just now on https://cults3d.com/en/3d-model/tool/printed-door-opener-to-help-against-the-spread-of-coronavirus), so all credit for the idea goes to them!
unfortunately their thing wasn't adaptable to my doors, couldn't open the source since i use openscad......
the source of this is in https://github.com/nohkumado/covid19_doorhandle
feel free to modify it!
rationale: places where people get in and out frequently, everyone touches the
doorhandle, even with appropriated metallic coating of certain sorts (copper,
silver etc) the handle is able to desinfect itself in a minimum time of 10 min,
if passage is more often, lets try to not let the handle be touched then.
Here comes this design, instead of using the hand, the forearm is used to make
lever on the handle and to pull the door closed (if you need to push, you can
Edit: i found a box of M6 screws with hex head and some winged nuts, added those stls one for straight knob, one for rounded knob (you can easily change the screw type on knob specs in the openscad source, be careful to take the git version!