ASA-CF (Carbon Fibre ASA) on Prusa XL

Nozzle Temp

270 °C

Range: 250 – 280 °C

Bed Temp

110 °C

Range: 100 – 120 °C

Print Speed

50

mm/s · max 60

Layer Height

0.20

mm · max 0.28

Fan Speed

20 %

1st layer: 0 %

1st Layer Speed

20

mm/s

Retraction

0.8 mm

@ 35 mm/s

Nozzle Type

Hardened

Required, abrasive

  Retraction Note

• A hardened nozzle is required for carbon fibre. Keep retraction short at 0.8 mm.

Settings

Recommended

Range

Nozzle Temperature

265 – 275 °C

250 – 280 °C

Bed Temperature

105 – 110 °C

100 – 120 °C

Print Speed

40 – 60 mm/s

up to 60 mm/s on this printer

First Layer Speed

20 mm/s

slower is better for adhesion

Layer Height

0.20 – 0.25 mm

0.20 – 0.28 mm

Fan Speed (Normal)

20 %

10 – 30 %

Fan Speed (1st Layer)

0 %

off for the first few layers

Retraction Distance

0.8 mm

Direct drive (Nextruder)

Retraction Speed

35 mm/s

30 – 40 mm/s

Nozzle Type

Hardened steel or ObXidian

Required, never brass; 0.6 mm is ideal

Dry Filament

80 °C for ≥ 5 h

print from a dry box in humid weather

Enclosure

Required

with filtration or good ventilation

Support Material

HIPS, ASA-CF (interface)

HIPS from a second toolhead

Wipe Tower Minimal Purge

35 mm³

Prusa's default for non-PLA materials

Printing Notes

ASA-CF adds carbon fibre to ASA for stiffness and less warping and shrinkage, with 80 – 82.5 MPa flexural strength and an 88 °C heat deflection temperature. It is more brittle than plain ASA (10.5 – 12 kJ/m² impact strength against 19 – 20), so handle spools and parts with care.

Carbon fibre is abrasive and wears brass nozzles. Fit a hardened nozzle, such as Prusa's ObXidian or nickel-plated hardened nozzle, on the toolhead that runs ASA-CF. On a multi-tool XL it is easiest to dedicate one toolhead to abrasive filaments.

Prusa gives 0.4 mm as the smallest nozzle and 0.2 mm as the thinnest layer for fibre-filled filaments, and OzFDM suggests a 0.6 mm hardened nozzle is ideal. The XL's 290 °C hotend limit sits above ASA-CF's 280 °C maximum.

Print ASA-CF enclosed, with filtration or good ventilation for the fumes. The XL heats only the bed tiles under and around your parts, so let a closed enclosure warm up before starting a small part.

Slicer: PrusaSlicer with the Prusa XL printer profile and a 0.4 mm nozzle. Dry the filament at 80 °C for ≥ 5 h before a long print; every figure above assumes dry filament.

Troubleshooting

Nozzle clogging partway through a print: Do a cold pull before printing, as Prusa recommends for composites, and dry the roll. OzFDM suggests a 0.6 mm hardened nozzle as the ideal size for ASA-CF.

Layers separating: Fibre-filled filaments bond less well between layers. Raise the nozzle toward 280 °C, drop the fan to 10 % and keep the enclosure closed.

Filament snapping in the feed path: ASA-CF is more brittle than plain ASA. Avoid sharp bends in the PTFE tube, keep the spool dry and do not leave loose filament kinked.