About this 3D model

Used Espresso grinds have to go somewhere! Knockboxes can start at $30 each... but you can make one at home for the cost of a flexi-straw, a screw, and an old coffee can! Note that because there is no shock absorption, this could damage your portaholder or filter baskets. So far, I haven't noticed any damage to my own equipment, but your mileage may vary. Flexi-straws are food-safe, but if it cracks, it could expose the non-safe screw underneath. For maximum safety, I recommend using a stainless steel screw. Warning: I do not guarantee the food safety of this Thing.