3D Printer Filament Dryer

In summer 2024, I built a 3D printer filament dryer. Filament which has absorbed moisture produces poor quality prints and results in print failures.  Most drying boxes on the market at the time were expensive and the cheaper ones perform poorly due to a lack of exhaust of humid air, so I wanted to create my own dryer to solve these issues. My goal was to create a low-cost dryer which can maintain a temperature of 50°C using closed-loop control. I considered resistive heating elements, infrared heaters, and Peltier modules. I ultimately decided to use a Peltier module due to its precise temperature control at moderately high temperatures.

The entire box was designed using SolidWorks. I used laser cut polycarbonate for the walls and ABS 3D printed components for the Peltier support, rollers and brackets. The primary criteria in material selection was to ensure that the heat deflection temperature of all the components is greater than 50°C. Off-the-shelf components include 608 bearings due to their availability, a PC fan for air extraction, and an aluminum heatsink which I modified to integrate with the system. I chose aluminum over copper since it provided 2/3 of the thermal conductivity for 1/4 of the price.

On the electronics side, I used an Arduino Uno, relays, a DHT22 temperature/humidity sensor, a Peltier module, an external 12V power supply for the fan and Peltier, and an LCD display for the current and setpoint temperature.

I programmed the box for a simple on/off setpoint for several reasons, but mainly that I wasn't expecting rapid temperature fluctuations. When the temperature is 2 degrees below the setpoint, the peltier module turns on, and vice versa. I implemented the setpoint target with two buttons and added a display timeout to constantly display the real-time temperature and humidity.

My next steps include better characterization of the thermal performance of the Peltier module, miscellaneous thermal improvements, and better packaging of the electronics.

Overall, this project not only taught me a lot about electronics and heat transfer, but the result is also useful in my day-to-day life.