Over the past few years, 3D printer speeds have continued to increase. Early systems typically printed at around 50 mm/s, while newer printers can reach 150 to 600 mm/s. Some high speed printers now have motion speeds of up to 800 mm/s, allowing the printhead to move much faster. However, as motion speed increases, the extrusion system faces a different challenge. Can the extruder and hotend process enough material to keep up?

For users, higher printing speeds mean shorter print times. But increasing speed is not simply a matter of moving the printhead faster. At higher speeds, more filament needs to enter the hotend within the same amount of time. The extrusion system needs to deliver more material, and the hotend needs to melt and extrude it faster. When the extrusion and material processing capacity cannot keep up with the motion system, the printer cannot make full use of its available motion speed. This became one of the key limitations in further improving high speed printing.

The development of Liber™ started with this problem. We focused on what happens to the filament after it enters the hotend, particularly how it flows and melts inside the hotend. The goal was to improve the hotend's ability to process material at higher throughput.

Starting with Flow Path Design

Increasing the heating capacity of a hotend is one way to increase its flow rate. During development, however, we found that heating capacity alone does not determine how efficiently the material can be processed. After entering the hotend, the filament still needs to go through the melting and flow process. As printing speed increases, the time available for this process becomes shorter, making the internal flow path more important.

We therefore focused on the path the filament follows inside the hotend. Liber™ uses a Separated Flow Path Design. By redesigning the internal flow path, the filament can gradually melt as it moves through the flow channel before reaching the nozzle.

We continued to adjust the flow path, melting region, and material convergence area, and used testing to examine the melting and flow behavior of different designs. For a high flow hotend, the flow path is where the filament transitions from a solid state to a stable molten state. This became the main focus of Liber™'s early development.

23 Rounds of Iteration

A flow path cannot be finalized through a single design. During the development of Liber™, we completed 23 rounds of structural iteration. Each new version was adjusted based on the test results from the previous version and then tested again.

The early tests focused on the basic flow path and melting process. As development continued, we refined the local flow path, material convergence areas, and pressure and flow behavior at higher material throughput. Simulation was also used to help evaluate different structural designs. The final results were always verified through actual printing.

Testing also revealed issues that were difficult to identify during the initial design stage. Some designs performed well in simulation but produced different results during actual printing. These findings were used to make further changes in the next design iteration. Across the 23 iterations, we adjusted the melting region, local flow path, and material convergence path. The final design had to meet requirements for flow rate, melting performance, pressure, and manufacturability.

The core flow path of Liber™ was established through this process.

The First DIY Product: Testing in Real Printing Conditions

After the initial structural validation, Liber™ entered real printing environments through its first DIY product, Rapido X.

Compared with laboratory testing, DIY users work with a much wider range of printers, extrusion systems, materials, and printing parameters. These different combinations created a variety of operating conditions. They allowed us to continue evaluating Liber™ in actual use and bring user feedback back into the development process.

This stage provided further validation of the flow path under real printing conditions. It also gave us more experience with material compatibility, extrusion system matching, and different printing parameters. These results provided a useful basis for the next stage of Liber™'s development.

As the technology matured, we began to look at how Liber™ could be integrated into a complete printer system.

From DIY to Full System Integration

The DIY product gave Liber™ the opportunity to operate in real printing environments and allowed us to gain experience with different equipment, extrusion systems, materials, and printing parameters. In a DIY setup, however, users need to select and adjust individual components themselves. The final result depends to a large extent on the specific configuration and tuning.

As high speed printing became an important capability of complete printer systems, the hotend also needed to work as part of the entire system. In a complete printer, the hotend needs sufficient material processing capacity and needs to work reliably with the extrusion system, temperature control system, printhead structure, and software parameters.

Early this year, we began discussions with Snapmaker. The two teams discussed the Liber™ technology and its application in a complete printing system, and then evaluated the potential for cooperation.

From the Technical Solution to Snapmaker U1

After the cooperation was confirmed, Liber™ entered the U1 integration stage. By this point, the core flow path had already completed its initial validation. The focus then shifted to adapting the high flow hotend to the specific requirements of U1.

The first step was hardware integration. This included matching the hotend with U1's extrusion system, mounting structure, and heating components. We also needed to verify the actual printing performance together with U1's temperature control system and software parameters. Through multiple rounds of prototype testing and actual printing, the two teams evaluated extrusion, melting, and flow performance under different conditions. The results were then used to adjust the relevant structures and parameters.

The testing gradually expanded from the hotend itself to its performance as part of the complete printing system. This allowed us to confirm the operating condition of Liber™ and its compatibility with U1.

Under the same test conditions, Liber™ achieved an up to 87% increase in maximum volumetric flow rate compared with the stock stainless steel hotend on U1.[1]

After Liber™ entered the U1 integration stage, Phaetus also evaluated the product structure and manufacturing process under mass production conditions. Precision machining, dimensional inspection, and assembly control were used to ensure that the validated design could be reproduced consistently across production units. For a hotend that needs to work with U1's extrusion system, mounting structure, and temperature control system, manufacturing consistency is an important part of the overall integration.

The transition from development prototypes to mass production requires consistency in the design, manufacturing process, and quality control. This allows the validated Liber™ design to be produced reliably and used in actual printing.

Following final confirmation of the solution, Liber™ will officially launch for Snapmaker U1 on September 22, 2026.

From One Flow Path to More Applications

The development of Liber™ started with the melting and flow of material inside the hotend.

The Separated Flow Path Design was developed through 23 rounds of structural iteration to establish the core flow path. Liber™ then entered real printing environments through a DIY product, where the design was tested with different equipment and materials. Early this year, Phaetus and Snapmaker began working together to adapt the existing technology to U1, including hardware and software integration, actual printing tests, and performance validation.

The U1 project extends Liber™ from an independent hotend solution to a complete printer system. We will continue to work on flow path design, material compatibility, manufacturing processes, control strategies, and system integration, and apply Liber™ to more products and printing applications.

[1] Under laboratory test conditions, printing speed increased by 87%. Test parameters: ambient temperature 24°C; heated bed temperature 100°C; material: Snapmaker ABS; nozzle temperature 280°C; acceleration 1000 mm/s²; single wall; layer height 0.2 mm; spiral vase mode; enclosed printing. The control group was the stock stainless steel hotend tested under the same conditions. Actual results may vary depending on model selection, test environment, and filament.