An espresso knockbox that really works for me. The upward pricks pierce into the dried 'cake' of coffee grounds that can be quite stubborn to remove when properly dried.
I separated two files because I placed them separately into Cura Ultimaker as to give different print settings to each section. They overlap in the disk that makes the base, so that the columns support the impact all the way to the bottom with higher infill and wall thickness. I went by this link to guide me through achieving this on Cura https://3dprinting.stackexchange.com/questions/6522/different-infill-in-the-same-part/6523

The base(cup) I printed with:

• 20% triangle infill, but 10 might be fine,
• 1.2mm wall thickness,
• 0.12 resolution,
• and 0.84mm top/bottom;
• fan speed at 20%;
• 105% material flow
• no support or raft.

For the columns I changed:

• 2mm wall/top/bottom thickness
• 80% infill

Ender 3 Pro white PLA

Issues:
There's some printing defects:

1. as the layering is slightly visible on the outside,
2. the columns seem to have some dots jutting out, but they are small and it doesn't bother me.
3. Somehow the disk at the bottom of the base, and the walls of the base seem to have some misalignment, don't know why.
4. Also, I've come to find the prongs very far apart and sometimes they hit the edge of the coffee filter.
5. It's a bit hard to clean, mostly because there's no treatment so everything gets lodged in the layers, but if edges were rounded would be a great help to make it more cleanable.

"It works perfectly, I love using it." my SO, true story.

Anyway, here's the project in Tinkercad, it's where I designed it.
https://www.tinkercad.com/embed/81gx03U7SxK