How to 3D Print a DIY Cold Drip Coffee Maker

If you’ve ever craved a crisp, smooth glass of iced coffee in the middle of summer but found store-bought versions too weak or watered down, there’s a better way. One designer has created a low-cost, at-home solution that makes rich, chilled coffee through slow, controlled dripping — and he’s sharing the blueprints with everyone.

The entire setup can be built at home using a 3D printer, some basic lab glassware, and maple rods — with all printable parts available for free. The whole device costs little and takes just hours to assemble.

What Is This 3D-Printed Coffee Maker?

Designed by Jonathan Odom, a product designer based in San Francisco and contributor to Instructables, this is a DIY cold drip coffee machine. It’s crafted mostly from 3D-printed components, a few pieces of standard laboratory glassware (like a flask and funnel), and some wooden rods. Odom made the STL files for all custom 3D parts available online for free download, so anyone with a printer can start building.

Why Slow Drip? The Science Behind Cold Coffee Extraction

Odom’s design uses the cold brew method — specifically, a slow-drip approach similar to Japanese-style cold drip or siphon cold brew. In this method, ground coffee is soaked in cold water and extracted drop by drop, typically at a rate of around three seconds per drop. This slow process allows the coffee to release its flavours gradually without extracting excessive acidity or bitterness. According to Odom, hot water pulls out coffee acids and caffeine much faster than cold water. By steeping coffee grounds in cold water over a period of two to six hours, you get less acidity and a smoother cup. He also notes that despite the cooler temperatures, the caffeine content remains comparable to that of a hot brew.

How to Build Your Own 3D-Printed Cold Drip Coffee Maker

To assemble the coffee maker, you’ll need the following materials: 3D-printed parts (all STL files are free to download), a laboratory flask (like those used in chemistry sets), a glass funnel, some tubing (including a small piece of brass tubing), maple rods for structural support, a valve, filter paper, and epoxy glue for assembling certain printed parts. Odom used Fusion 360 for designing all components, and says most standard consumer-grade 3D printers can handle the prints without issue. Surface finishing like sanding or painting with acrylic is optional.

The key engineering challenge is creating a stable and consistent drip system. Odom solves this by inserting a short piece of brass tubing into the valve area to ensure even water flow. The coffee grounds go into the funnel, which is lined with filter paper. Another filter sits on top of the coffee bed to ensure even saturation — without it, water could bore a hole straight through the grounds, leading to under-extracted, weak coffee.

Assembly is straightforward if you follow Odom’s step-by-step tutorial. Most of the parts slot or screw together easily, though some 3D-printed joints benefit from epoxy for a solid hold. The design is modular, and the final machine looks clean and functional — though Odom also added a cosmetic sanding and spray-paint step for a more polished look.

How to Use the Cold Drip Coffee Maker

Using the machine is simple once it’s built. Start by placing ice in the upper flask, which is positioned upside down to let melted ice water slowly drip through the system. The drip rate is controlled by the valve — aim for roughly one drop every three seconds. Place your coffee grounds in the funnel, making sure not to overfill, and cover them with a filter paper. Add another filter on top to promote even water distribution.

Then, let it drip. Odom reports that brewing a full batch — enough for roughly two cups of coffee — takes about four hours. That may sound long, but for coffee enthusiasts, it’s part of the experience: slow, controlled extraction that results in a cleaner, sweeter, and more complex cup. The final brew is chilled, smooth, and ideal for hot summer days.

Frequently Asked Questions

Do I need a high-end 3D printer to make this coffee maker?

No, you don’t need an expensive or industrial 3D printer. Jonathan Odom used a standard consumer-grade 3D printer to produce all the parts, and he confirmed that they print easily with common settings. The key is having a reliable printer that can handle the small, detailed components.

What kind of lab glassware do I need?

You’ll need a basic laboratory flask (like a round-bottom or Erlenmeyer flask) and a glass funnel. These are standard items often found in school or research lab supply kits. They’re not everyday household items, but they’re widely available online or from scientific equipment suppliers.

How long does it take to brew coffee with this drip system?

Brewing time is around four hours for a typical two-cup batch. The slow drip rate — approximately three seconds per drop — ensures a smooth and well-extracted cup. You can adjust the drip speed slightly depending on taste preferences, but slower usually means better flavour clarity.

Can I use any coffee beans with this cold drip system?

Yes, you can use any coffee beans, but the best results come from freshly roasted beans suited for cold brewing. For cold drip, medium to light roasts often highlight fruitier and more acidic profiles, while medium-dark roasts bring out deeper sweetness. Proper grind size — similar to coarse sea salt — is also important.

Is the brass tubing necessary for the drip mechanism?

Yes. The brass tubing inserted into the valve helps regulate a steady and even drip rate. Without it, achieving the ideal three-second interval per drop can be difficult, and the extraction may become inconsistent.

Recommended FrontStreet Beans for Cold Drip Coffee

For a refreshing cold drip brew, try FrontStreet Coffee’s Ethiopia Humbera — a bright, juicy single origin with notes of berry and citrus, perfect for highlighting the clean extraction of slow drip methods. Alternatively, their Classic Blend offers a balanced medium-dark roast with notes of chocolate and nuts, ideal for those who prefer a richer cold coffee. Both beans are freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.