PA6-CF (Carbon Fibre Nylon) on Prusa MK4

Nozzle Temp

280 °C

Range: 270 – 290 °C

Bed Temp

80 °C

Range: 60 – 90 °C

Print Speed

50

mm/s · max 60

Layer Height

0.20

mm · max 0.28

Fan Speed

10 %

1st layer: 0 %

1st Layer Speed

20

mm/s

Retraction

1.0 mm

@ 35 mm/s

Nozzle Type

Hardened

Required — abrasive

Retraction Note

• A hardened nozzle is mandatory. Minimal retraction.

Settings

Recommended

Range

Nozzle Temperature

280 °C

270 – 290 °C

Bed Temperature

80 °C

60 – 90 °C

Print Speed

50 mm/s

up to 60 mm/s on this printer

First Layer Speed

20 mm/s

slower is better for adhesion

Layer Height

0.16 – 0.24 mm

0.12 – 0.28 mm

Fan Speed (Normal)

0 – 20 %

–

Fan Speed (1st Layer)

0 %

–

Retraction Distance

1.0 mm

Direct drive

Retraction Speed

35 mm/s

–

Nozzle Type

Hardened steel

Required — this filament will destroy brass

Dry Filament

80 °C for ≥ 12 h

print from a dry box in humid weather

Enclosure

Required — add one

Required — this printer is open-frame, so an enclosure must be added

Support Material

PVA

–

Printing Notes

PA6-CF is the strongest filament OzFDM sells — 60 – 65 MPa tensile and a 4900 – 5000 MPa flexural modulus, with a 200 °C heat deflection temperature.

It demands a hardened nozzle, a hot chamber and genuinely dry filament. Treat any one of those as optional and the print will fail.

The Nextruder's short filament path keeps retraction around 1 mm — a fraction of what a Bowden machine needs, and close to PrusaSlicer's stock value.

Input Shaper is enabled by default on the MK4, so the speeds above are achievable without the ringing you would get on an older machine.

Slicer: PrusaSlicer. Dry the filament at 80 °C / ≥ 12 h before a long print — every figure above assumes dry filament.

Troubleshooting

Steam, popping and a furry surface — PA6 absorbs about 1 % moisture. Dry twelve hours at 80 °C and feed from a sealed dry box during the print.

Layers separating under load — Nozzle too cool for the speed. Push to 290 °C and slow to 40 mm/s — layer bonding in nylon is heat-driven.

Parts distorting after they come off the bed — PA6 continues to absorb moisture and grows slightly. Anneal, then condition the part before measuring it.