Cup for grinding directly into, and / or giving the ground coffee a firm shake to break down the clumps to get a good distribution and extraction. I designed it for my 58 mm Rocket portafilter.
I designed it after watching this video:
https://www.youtube.com/watch?v=C9u9S_-PcwQ
Uploaded after watching this video:
https://www.youtube.com/watch?v=X3bEjJ_S2V0&t=630s
espresso_piston_cap_rocket.stl | 248.7KB |