I wanted retractable feet for a project and figured the click pen mechanism would be the perfect solution so I went looking for models.

I found a few on grabcad and then found 3d-printy's fidget button.
https://www.thingiverse.com/thing:4945227
I proceeded to modify that into what I needed.

Mechanism has just shy of a 1/4" throw but can be be modified.

Foot/Cam is left hand thread 1/4-20. Right hand threads self loosened.

These are the pads I used for the bottom of the feet,
https://www.amazon.com/gp/aw/d/B0BM434B1M?psc=1&ref=ppx_pop_mob_b_asin_title&th=1

Printed with a .35 Nozzle at .1 layer height.
Modeled in imperial so scale by 25.4 or 2540% depending on your software

Robo 3D

C2 R2

Yes