Getting Great Prints on the Prusa MK4
The MK4 is the MK4S's direct predecessor: same open-frame, no-enclosure, no-auxiliary-fan design, without the newer input-shaper accelerometer built in as standard. For material tuning purposes the two are effectively identical.
Is the Prusa MK4 enclosed?
Enclosure: No. Auxiliary part-cooling fan: No.
Open-frame with no enclosure and no auxiliary fan, exactly like the MK4S. The main practical gap between MK4 and MK4S is input-shaping hardware and some sensing refinements — the thermal and cooling story this guide covers is the same on both.
Baseline settings for Prusa's Prusa MK4 profile
Prusa publishes one shared filament-profile baseline across its OrcaSlicer-family lineup rather than a separate one per model, so these are the numbers the Prusa MK4 starts from — use them as the floor and calibrate flow/retraction per spool:
| Material | Nozzle | Bed (textured/hot) | Fan max |
|---|---|---|---|
| PLA | 220 °C | 60 °C | 100 % |
| PETG | 240 °C | 85 °C | 90 % |
| ABS | 260 °C | 105 °C | 80 % |
| TPU | 240 °C | 35 °C | 100 % |
MK4 owners: what to check before assuming a settings problem
No built-in accelerometer means input shaping needs manual setup (or an add-on accelerometer) if ghosting appears at higher speeds. Until then, keep outer wall speed conservative rather than chasing print time — see the ghosting guide.
ABS/ASA needs the same enclosure workaround as any open Prusa. See the ABS/ASA warping guide.
PETG adhesion and stringing. Standard fix order applies: dry, cool 10 °C, then retraction. See PETG stringing and PETG bed adhesion.
Symptoms this machine's form factor is prone to
Without a chamber, the Prusa MK4 inherits the classic open-printer failure modes in full: warping and adhesion loss on hot materials, and higher sensitivity to room drafts than any enclosed machine has to deal with:
- Warping and bed adhesion — the two symptoms an enclosure would otherwise mitigate.
- First-layer problems — open frames are more exposed to bed-leveling drift from handling and transport.
- Ghosting and ringing — lighter open frames typically need more belt-tension attention than an enclosed cube at the same speed.
A sane first-print checklist
- Match the plate/surface selection in the slicer to what's actually on the bed, if the machine supports more than one build surface. Mismatches are the leading cause of "it should have stuck" reports.
- Run a flow-ratio calibration on any filament that isn't the exact spool Prusa's profile was written against. Off-brand and generic spools routinely land several percent off the stock flow ratio; that shows up as over- or under-extrusion that looks like a hardware problem but isn't.
- Change one variable per test print. Temperature, fan speed and retraction all interact; the fastest way to a dialed-in Prusa MK4 is small, single-variable tests read one at a time, not three changes at once.
For the full Prusa lineup and its common failure modes, see the Prusa troubleshooting hub.
Frequently asked questions
What baseline temperatures does the Prusa MK4 profile use?
Prusa’s stock profile starts PLA at 220 °C nozzle and 60 °C bed with 100 % fan, PETG at 240 °C and 85 °C with 90 % fan, ABS at 260 °C and 105 °C with 80 % fan, and TPU at 240 °C and 35 °C with 100 % fan. Use these as the floor and calibrate flow and retraction per spool — off-brand filament routinely lands several percent off the stock flow ratio.
Why does my Prusa MK4 show ghosting at higher speeds?
The MK4 has no built-in accelerometer, so input shaping needs manual setup or an add-on accelerometer if ghosting appears at higher speeds — that is the main hardware gap to the MK4S. Until input shaping is set up, keep outer wall speed conservative rather than chasing print time, and give belt tension the usual open-frame attention.
Do the Prusa MK4 and MK4S need different print settings?
No — for material tuning the two are effectively identical. The MK4 is the MK4S’s direct predecessor with the same open-frame, no-enclosure, no-auxiliary-fan design; the practical differences are input-shaping hardware and some sensing refinements. The thermal and cooling behaviour, and therefore the temperature, fan and adhesion settings, are the same on both machines.
Want these numbers turned into a personalized fix list for your Prusa MK4?
Answer five quick questions about your printer, filament and build plate, and our rule engine turns them into a prioritized fix list with exact slicer values — the same knowledge these guides are written from.
Get a personalized fix list in 2 minutes — free Works with Bambu Studio, OrcaSlicer, PrusaSlicer and Cura. No account needed.Sources
- OrcaSlicer vendor profiles — SoftFever/OrcaSlicer (GitHub)