Phaetus · next-generation High-Flow

Phaetus Rapido X
100+ mm³/s and up to 350 °C

The next generation of Phaetus' flagship hotend: Liber™ High-Flow Module, 120 W heater, PT1000, replaceable M6 nozzle, EndCoat® II and a construction designed for high-speed printing with engineering-grade materials.

100+
mm³/s max flow
350°C
temperature
120 W
heater
M6
replaceable nozzle
Phaetus Rapido X — next-generation high-performance hotend

Rapido X is not simply another Rapido version with a more powerful heater. Phaetus has effectively redesigned the key hotend components around one goal: giving modern high-speed 3D printers enough melting capacity without sacrificing temperature stability, extrusion quality or the ability to print engineering-grade materials.

At the heart of the design is the new Liber™ High-Flow Module, which changes the geometry of the melting zone itself. Add a 120 W heater, PT1000, temperatures up to 350 °C, a replaceable M6 nozzle and the new generation of EndCoat® II wear-resistant coating, and you get a hotend designed for both high-speed and engineering-material printing.

What's New in Rapido X

Liber™ High-Flow
A new melting-zone geometry instead of a conventional straight channel.
100+ mm³/s
Maximum volumetric flow rate claimed by Phaetus in its test configuration.
EndCoat® II
A new generation of wear-resistant coating for engineering and abrasive materials.
120 W + PT1000
High-temperature configuration for printing up to 350 °C.
M6
Replaceable nozzle with access to a broad ecosystem of compatible solutions.
50 N·m
Reinforced construction with high claimed torque resistance.
Key technologies of Phaetus Rapido X

Liber™: How Phaetus Rethought High-Flow

In a conventional hotend, increasing flow usually means extending the melting zone. It works, but the design quickly becomes longer, heavier and less suitable for high-speed motion systems.

With Rapido X, Phaetus took a different approach. The Liber™ High-Flow Module uses a more complex material path and increases the effective heat-transfer area. According to the manufacturer, this design improves heat-transfer efficiency by 117% compared with a conventional straight channel.

Larger Contact Area
The filament absorbs more heat before it even reaches the nozzle itself.
More Complete Melting
A smaller temperature difference between the outer and central regions of the material flow.
Higher Volumetric Flow
The hotend can deliver more molten material without a sharp drop in melt temperature.
Liber High-Flow Module in Phaetus Rapido X

100+ mm³/s: What Phaetus' Numbers Actually Mean

65 mm³/s
Stable Printing Flow
Stable extrusion performance claimed by the manufacturer in its test configuration.
100+ mm³/s
Max Flow Rate
Maximum volumetric flow rate achieved in Phaetus laboratory testing.
1300 mm/s
Max Printing Speed
Maximum speed achieved on the manufacturer's test platform.
!
1300 mm/s does not mean every printer will print at 1300 mm/s
These figures were achieved by Phaetus on a dedicated test platform using PLA+, a temperature of 230 °C, acceleration of 15,000 mm/s², a 0.2 mm layer height, 0.7 mm line width and Vase Mode. The actual system limit depends on printer kinematics, extruder, nozzle, material and model geometry.
Phaetus Rapido X performance test — 100 mm3/s and 1300 mm/s
Phaetus Rapido X printing speed comparison

It's Not Just About Flow Rate

Volumetric flow alone means little if high-speed printing leads to under-extrusion, stringing or a sharp drop in surface quality.

In Phaetus demonstration tests, Rapido X shows cleaner retractions, more stable bridges and smoother surfaces compared with a basic high-flow solution. The goal is therefore not simply to “push more plastic”, but to maintain controlled melting at high material throughput.

Phaetus Rapido X print quality comparison

Cooling: Fighting Heat Creep

The more powerful the heating zone, the more important it becomes to isolate it from the cold side of the hotend. Otherwise, heat travels upward through the heatbreak, the filament begins to soften too early and the system develops classic heat creep.

Rapido X doubles the cooling surface area. Phaetus has also optimized the heatsink and heatbreak geometry to remove heat more efficiently exactly where it is no longer needed.

Phaetus Rapido X cooling system and heat creep protection

Micron-Level Manufacturing Precision

High flow depends on more than heater power and melting-zone geometry. The faster the filament moves, the more critical the internal bore accuracy, surface quality and precision fit between hotend components become.

For Rapido X, Phaetus specifies an internal heatbreak bore roughness of Ra ≤ 0.2 µm. The smooth internal surface promotes smoother filament feeding and reduces material buildup, while high-precision component mating helps minimize gaps that can cause melt leakage or clogging.

Ra ≤ 0.2 µm
Low internal bore roughness promotes smoother filament travel and reduces material residue buildup.
Precision Fit
Micron-level machining precision ensures accurate alignment of the filament path components and reduces the risk of leaks and clogging.
Micron-level manufacturing precision and heatbreak of Phaetus Rapido X

EndCoat® II and Composite Printing

At high speeds, abrasive materials place even greater stress on the nozzle and internal filament path. This is why Phaetus places particular emphasis on its new-generation EndCoat® II coating.

10 kg
PA-CF processed by a hardened steel nozzle before reaching the specified wear level.
30 kg
PA-CF processed by an EndCoat® nozzle before reaching a comparable wear level.
70 kg
PA-CF processed in the silicon carbide nozzle test.
Phaetus Rapido X nozzle wear resistance comparison

Up to 350 °C: Not Just High-Speed PLA

Rapido X is equipped with a 120 W ceramic heater and a replaceable PT1000 sensor. Its maximum operating temperature is rated at 350 °C, so its application range extends far beyond PLA and PETG.

PLA TPU / TPE PETG ABS ASA PA PC PA-CF / GF PEI PEEK

Important: the ability to heat the hotend to the required temperature does not automatically make the entire printer ready for PEEK or PEI. These materials also require suitable chamber and build plate temperatures, printer kinematics, properly prepared filament and other compatible system components.

Phaetus Rapido X — high-temperature printing up to 350 degrees

M6 and a Universal DIY Platform

Phaetus has not locked Rapido X into a proprietary nozzle ecosystem. It uses a replaceable M6 threaded interface, while the mounting section provides eight open mounting holes: 4×M3 + 4×M2.5.

Replaceable M6 Nozzle
Choose nozzle material and diameter for a specific application without replacing the entire hotend.
Custom Adapters
Eight mounting points provide greater freedom when integrating Rapido X into custom toolhead systems.
Phaetus Rapido X universal interfaces and mounting

Reinforced Construction for High-Speed Motion Systems

At the speeds Rapido X was designed for, mechanical rigidity becomes just as important as heater power.

Phaetus uses its own anti-twist construction with titanium-alloy components. The manufacturer claims torque resistance of up to 50 N·m and separately tests the assembly for accidental collisions and repeated mechanical loads.

Reinforced anti-twist construction of Phaetus Rapido X

Technical Specifications

Model
Phaetus Rapido X
Filament
1.75 mm
High-Flow Module
Liber™ High-Flow Module
Maximum Flow Rate
100+ mm³/s*
Stable Flow Rate
65 mm³/s*
Maximum Test Speed
1300 mm/s*
Maximum Temperature
350 °C
Heater
120 W ceramic heater
Temperature Sensor
Replaceable PT1000
Nozzle
M6, replaceable
Mounting
4×M3 + 4×M2.5
Coating
EndCoat® II
Heatbreak
Ra ≤ 0.2 µm

* Speed and volumetric flow figures are based on Phaetus test results and depend on printer configuration, material, temperature, nozzle and print settings.

Who Is Rapido X For?

High-Speed CoreXY Printers
When printer mechanics can already move fast and the hotend becomes the limiting factor.
Engineering Materials
PA, PC, CF/GF composites and high-temperature polymers that require both high temperature and stable melt flow.
Large Nozzles
0.6–1.0 mm and above, where volumetric flow quickly becomes the main system limitation.
DIY and Custom Printers
Open mounting options and the M6 interface make Rapido X attractive for custom toolhead configurations.

Rapido X — a Hotend for the Next Generation of High-Speed Printers

Over the past few years, 3D printer motion systems have become so fast that the hotend itself is increasingly becoming the bottleneck. Simply using a longer nozzle or increasing the temperature is no longer enough.

What makes Rapido X particularly interesting is that Phaetus approaches the system as a whole: melting, cooling, mechanical rigidity, manufacturing precision, wear resistance, high-temperature capability and compatibility. That makes it far more than just another “high-flow hotend”.

 
Phaetus Rapido X

The Next Generation of Rapido Is Now at LFL3D

Phaetus Rapido X is designed for applications where a conventional hotend is already limiting the printer's capabilities. Explore the specifications and order Rapido X from LFL3D.

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