Improving Your 3D Printing Filament: A DIY Dryer Project Revisited

In this guide, we explore a fully DIY approach to drying 3D printing filament, based on the V2 iteration of a project by Saša Karanović. Designed to overcome common pitfalls of commercial dryers, this version uses a custom controller PCB, precise sensors, and a simple food container to create an effective, low-cost drying solution. Below, we answer frequent questions about the build, components, and performance.

What is the DIY filament dryer V2?

The DIY filament dryer V2 is a second-generation design by Saša Karanović, born from feedback on an earlier version that reused an existing commercial dryer. This time, the build is more genuinely DIY: it centers around a 5-liter food storage container, a custom controller board, an SHT30 temperature and humidity sensor, a 100K NTC temperature sensor, and a 12V polyimide resistive heater. The design is fully documented on GitHub with a bill of materials (BOM) and assembly instructions for anyone to replicate.

Improving Your 3D Printing Filament: A DIY Dryer Project Revisited — Source: hackaday.com

What components are needed to build this dryer?

The core components include: a 5L food storage container (acts as the chamber), an SHT30 sensor for precise temperature and humidity readings, a 100K NTC thermistor for additional temperature monitoring, a custom PCB controller board that processes sensor data and switches the heater on or off, and a 12V polyimide resistive heater. You’ll also need wiring, power supply, and basic soldering tools. The BOM and schematics are available in the project’s GitHub repository.

How does the controller board work?

The custom controller board is the brain of the dryer. It connects to the SHT30 and NTC sensors, reading real-time temperature and humidity. Using this data, it cycles the 12V polyimide resistive heater on and off to maintain a target drying temperature (typically around 50-60°C for PLA or PETG). The board can be programmed to adjust settings, and the design includes safety cutoffs. All firmware and PCB files are open source on GitHub, allowing users to modify the logic as needed.

What improvements does V2 have over V1?

The first version reused an existing filament dryer and added a custom controller. V2, however, builds everything from scratch, making it a true DIY project. Key improvements include: a dedicated custom PCB designed specifically for this application (V1 likely used a generic board), better sensor placement, and more detailed online documentation with a proper GitHub project. The V2 also addresses feedback on airflow by recommending the container be left slightly ajar to let moist air escape.

Why do filament dryers need to be left open?

A common issue with both DIY and commercial filament dryers (like Sunlu models) is that saturated warm air has no way to escape. The moisture absorbed from the filament evaporates into the heated air inside the chamber, but without ventilation, that humid air stays in contact with the filament and slows down drying. By leaving the container slightly ajar, cooler, drier air from outside is allowed in. That air can absorb more moisture, significantly improving drying efficiency. This simple trick is recommended even for commercial units.

Where can I find build instructions and files?

All documentation for the DIY filament dryer V2, including assembly guide, bill of materials, PCB design files, and firmware source code, is hosted on GitHub under Saša Karanović’s project. The page lists step-by-step instructions, wiring diagrams, and programming details. It is a complete resource for anyone wanting to replicate or modify the dryer. Make sure to check the latest revision for potential improvements.

Is this dryer suitable for all filament types?

Yes, the dryer can handle various filaments such as PLA, PETG, ABS, and nylon by adjusting the temperature setpoint via the firmware. The 12V polyimide heater can reach temperatures sufficient for most materials, and the SHT30 sensor ensures accuracy. However, for high-temperature filaments like polycarbonate, you may need to upgrade the container or insulation. Always follow material-specific drying guidelines and monitor humidity levels during the process.

What makes this design better than commercial dryers?

This DIY dryer offers several advantages over commercial units like Sunlu: it is fully customizable (you control the sensors, heater power, and chamber size), costs less to build if you have basic electronics skills, and the open-source nature means you can repair or upgrade it easily. The V2 design specifically addresses the common ventilation flaw, and the use of a high-quality SHT30 sensor provides more precise humidity readings than many budget commercial dryers. It’s an excellent project for makers who want full control and transparency in their filament drying process.