Technical Specifications

• Printer Compatibility: Anycubic Kobra S1 / Kobra S1 Combo
• Nozzle Diameter: 0.25 mm
• Maximum Operating Temp: Up to 320°C
• Nozzle/Hotend Material: All-Metal Construction / Brass Nozzle with Ceramic Composite Throat
• Filament Compatibility: 1.75 mm (PLA, PETG, ABS, ASA, TPU*)
• Max Flow Rate / Speed: Optimized for high speeds (up to 600 mm/s printer capabilities) Important Note: While the Kobra S1 hotend supports TPU, small 0.25mm nozzles create higher backpressure. Extremely soft filaments (e.g., TPU < 95A) require slower extrusion speeds to avoid jams.

Maintenance & Care Tips

Slicer Adjustment (Crucial)

• Adjust Line Width & Layer Heights: Update your Anycubic Slicer / OrcaSlicer profile to reflect the 0.25mm nozzle. Keep layer heights generally between 0.05mm and 0.16mm (the rule of thumb is keep layer height under 60-80% of nozzle diameter).
• Lower Print Speeds & Adjust Volumetric Flow: Because a 0.25mm nozzle restricts flow volume, lower the maximum volumetric speed in your slicer to avoid extruder slipping or skipping steps.

Prevention & Anti-Clogging

• Purge Filaments Properly: When transitioning from high-temperature materials (like ABS or ASA) back to lower-temperature filaments (like PLA), thoroughly purge at the higher temperature to ensure no high-temp residue stays inside to clog the small 0.25mm orifice.
• Keep Filaments Dry: Moisture in filament causes steam pockets that can lead to partial clogs—a issue magnified by smaller nozzle diameters.
• Avoid Abrasive Materials: Standard brass 0.25mm nozzles will wear out rapidly when printing carbon fiber, glass fiber, glow-in-the-dark, or wood-filled filaments. Stick to non-abrasive filaments or switch to a hardened steel variant for composite materials.

Cleaning Techniques

• Cold Pull (Atomic Method): If experiencing partial clogging or inconsistent extrusion, perform a cold pull using nylon or cleaning filament. Heat to ~230°C, let it cool down to ~90°C, and pull the filament firmly out to remove trapped debris from the nozzle tip.
• Nozzle Cleaning Needle: Use a 0.20mm or smaller cleaning needle from the tip upward only when the hotend is heated to clear minor blockages. Do not force thick needles into a 0.25mm orifice to prevent expanding or damaging the tip geometry.