Swap Nice, Dry Filament in Your Prusa CORE One with the COREBOXX and Semi-Smart

The Prusa CORE One is a very appealing 3D printer that gives the user complete freedom and many modern features. But it doesn’t have the Prusa XL’s multiple toolheads. Instead, CORE One owners need to rely on an MMU if they want to work with more than one filament roll automatically. Unfortunately, the current MMU3 can be a bit of a pain and leaves a lot to be desired. To solve its issues, Voxel3D designed the COREBOXX filament management system. Even better, they just upgraded it with smart humidity control.

The fact that this is even possible is a testament to Prusa’s commitment to user freedom — something that is becoming less and less common in the consumer 3D printer industry. Prusa is so dedicated to that philosophy that they gave the CORE One a “GPIO hackerboard,” which acts as a direct link between the printer’s control board and whatever other hardware the user wants to attach. That is crucial to the functionality of the COREBOXX and its ability to handle humidity.

Before we dive into that capability, which was the topic of Voxel3D’s most recent video, you should know that the COREBOXX is a filament management system that reconfigures the MMU3, with design inspiration from open-source community projects like the “Filamentalist” rewinder for the ERCF (Enraged Rabbit Carrot Feeder) v2, which is popular among Voron builders. COREBOXX does a lot to make the MMU3 user experience more pleasant, but one of the key features is that rewinder system that eliminates the MMU3’s troublesome filament buffer arrangement.

Voxel3D designed the COREBOXX specifically for the Prusa CORE One and there is a whole video about it, for those of you who want to know more.

But Voxel3D’s newest video is about filament drying and the COREBOXX’s system for handling that. Wet filament is bad and dry filament is good. Voxel3D designed COREBOXX to use desiccant, a heater, and a fan for drying and their custom controller lets the CORE One manage those. It interfaces through the GPIO hackerboard that we mentioned earlier, which allows for a seamless setup.

That custom controller is called the “Semi-smart” and it connects to the GPIO hackerboard. The controller hosts an Arduino Nano R3 development board and has connections for the MMU (in and out), a user interface (with buttons and OLED screen), an LED strip, a thermistor, a PTC heater, fans, and a servo. In the COREBOXX and paired with a CORE One, it provides control over all of the drying functions and works in conjunction with the MMU.

COREBOXX and Semi-smart are open-source and you can build them using the provided files without buying anything from Voxel3D. But if you want to make things easier on yourself and likely save money compared to self-sourcing components, there are kits available for both through Blurolls.