Modular Knock Box for Portafilter Machines

 

 

 

🇺🇸 **Modular Knock Box System for Portafilter Espresso Machines** This modular knock box system is designed for portafilter espresso machines such as the **Ninja dual-brew espresso maker**. After brewing, the used coffee grounds form a “puck” that can be cleanly and conveniently disposed of in this stylish container The system consists of multiple layers (“parts”) that align through **small guiding pins**. These pins make the assembly extremely precise — no manual positioning required. Once glued, the elements fit perfectly together. I use UHU Plastic Glue The base footprint of the system is **130 × 160 mm**, while the total height depends on the selected modules **Assembly note**: To build a complete box, print **one variant** of each part (Parts 1–6 + pins) The mid section (Part 2) is **optional** — if you leave it out, only **14 pins** are needed instead of 22

Available Modules

Part 1: Knock Box Container
• Variant 1 – 70 mm height
• Variant 2 – 90 mm height
• Variant 3 – 110 mm height

Part 2: Mid Section (optional)
• Variant 1 – 10 mm height
• Variant 2 – 16 mm height
• Variant 3 – 22 mm height

Part 3: Bottom Plate
• Variant 1 – 45° corner
• Variant 2 – Rounded
• Variant 3 – Straight
• Variant 4 – Modern angled (floating appearance)

Part 4: Lid Base
• Variant 1 – Solid
• Variant 2 – With ventilation openings

Part 5: Lid Top
• Variant 1 – Closed surface
• Variant 2 – Patterned closed surface
• Variant 3 – With ventilation openings

Part 6: Knock Bar
• Variant 1 – Round
• Variant 2 – Flattened

Special Features

Mid Section (Part 2)
This module includes two large inner cavities that are not visible after assembly. They reduce material usage and give you the option to insert weights if you want a more premium, heavier feeling. It also serves as a visual accent, since it can be printed in a contrasting color

Lid (Parts 4 & 5)
Both parts are available with optional **ventilation openings**. These can help with moisture from fresh coffee pucks, or simply be chosen for aesthetic reasons. The ventilated top (Part 5) can also be combined with the closed lower lid (Part 4) if you prefer

Knock Bar (Part 6)
The knock bar includes a **small anti-rotation nose** that prevents the bar from twisting or sliding out during use. This ensures that the bar stays exactly where it should while knocking out the coffee puck

Print Recommendations
• Some parts are sliced with **adaptive layer heights**, allowing for improved detail quality.
• For **Part 5 (Lid Top)** I strongly recommend enabling **ironing**, which creates a very smooth and refined top surface.
• All test prints were performed using **PLA**, with **no temperature-related issues** from hot coffee pucks

Customization

This system was designed to be mixed and matched. I’m excited to see your creative combinations — both in **shape variations** and **color choices**. Feel free to combine modules in any arrangement you like

Thanks for checking out my design

And remember: Life’s too short for bad coffee — and for boring prints. ☕😉

 

Lastly:

 

Commercial use of any of my designs is strictly prohibited**. All of my designs are exclusively available on my profile on Makerworld.
If you come across my designs on other platforms, please let me know so I can take appropriate action.
From the beginning, I’ve relied on the honesty of users in order to offer all my content for free.

 

Regards, Niklas