This is a Hog tool for espresso preparation. It was inspired by the following designs and the discussion around it on the Decent Espresso community. There was an earlier 3D print design posted to the same community, from which I also learned a lot.
https://www.instagram.com/p/CNpJBz7hRCG/
(original reddit post: https://www.reddit.com/r/espresso/comments/mqpqrm/advanced_espresso_comparing_two_shots_with_hog/)
https://community.baristahustle.com/t/lets-talk-about-the-hog/2000
https://sworksdesign.com/PorcuPress-p379522166
It uses acupuncture needles from Aliexpress in 0.6x40 mm (diameter/length of needle without handle). I'm adjusting the hole sizes for shrinkage in the model rather than in the slicer.
It uses brass tubing in 6mm diameter for the guides. I put soft helical springs on these.
It uses threaded rod and a nut for height stopper.
The top element can be made with different hole patterns.
The author hasn't provided the model origin yet.