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Prusa Research
Prusa Research Original Prusa MK4S
FDM filament printer. Build volume: 250 × 210 × 220 mm.
Assessed from documentation Updated on October 4, 2026
How to recognize it: Check the full model name “Original Prusa MK4S” on the label or in device information. Suffixes and revisions identify different models; check the source before selecting parts.
Technical specifications
Manufacturer specifications for the listed configuration. Notes identify accessories, measurement conditions and calculated values.
Technology and structure2
| Technology | FDM |
|---|---|
| Build area shape | Rectangular |
Build area and volume4
| Build area X | 250 mm |
|---|---|
| Build area Y | 210 mm |
| Build area Z | 220 mm |
| Build volume | 11.55 L Calculated from nominal X × Y × Z dimensions. |
Hardware6
| Installed toolheads / extruders | 1 |
|---|---|
| Extruder type | Direct drive |
| Filament diameter | 1.75 mm |
| Standard nozzle | 0.4 mm |
| Nozzle material | Brass CHT high-flow |
| Build plate | Removable magnetic PEI spring steel |
Temperatures2
| Maximum hotend temperature | 290 °C |
|---|---|
| Maximum bed temperature | 120 °C |
Resolution2
| Minimum layer thickness | 0.05 mm |
|---|---|
| Maximum layer thickness | 0.3 mm |
Features5
| Multicolor system | MMU3 Optional accessory. |
|---|---|
| Colors with documented configuration | 5 With optional MMU3. |
| Automatic leveling | Yes |
| Filament runout sensor | Yes |
| Power loss recovery | Yes |
Connectivity2
| Control display diagonal | 3.5 in |
|---|---|
| Listed slicers | PrusaSlicer |
Dimensions and weight4
| Machine width | 500 mm |
|---|---|
| Machine depth | 550 mm |
| Machine height | 400 mm |
| Net weight | 7 kg |
Technical sources: Original Prusa MK4S — documentazione ufficiale
Undocumented specifications (25)
- Kinematics: Not documented
- Shared dual-nozzle area X: Not documented
- Shared dual-nozzle area Y: Not documented
- Shared dual-nozzle area Z: Not documented
- Enclosed as standard: Not documented
- Available nozzle diameters: Not documented
- Chamber heating: Not documented
- Maximum chamber temperature: Not documented
- Advertised maximum print speed: Not documented
- Advertised typical print speed: Not documented
- Maximum travel speed: Not documented
- Maximum acceleration: Not documented
- Maximum volumetric flow: Not documented
- Camera: Not documented
- Air filtration: Not documented
- Control display: Not documented
- Connectivity: Not documented
- Firmware: Not documented
- Internal storage: Not documented
- Manufacturer-listed materials: Not documented
- Rated power: Not documented
- Power supply: Not documented
- Advertised noise: Not documented
- Leveling method: Not documented
- Advertised Z accuracy: Not documented
No published compatibility for this printer.
Accessories with verified compatibility
| Accessory | Printer variant | Status |
|---|---|---|
| eSUN eBOX Pro filament dryer eBOX Pro | Original Prusa MK4S | Compatibility declared by the seller Verified on October 12, 2026 1.75 mm filament documented by the printer manufacturer; the dryer does not connect to the printer. No hands-on test. |
Related guides
General guides help identify print defects. Follow the manual for your exact model and variant for disassembly, maintenance and calibration.
- First layer not sticking: causes and checks
How to recognise a first layer that is too high, too squished or uneven and fix it in order: plate cleaning, slicer profile, leveling, Z offset. Based on official guidance from Bambu Lab, Prusa, Creality, Elegoo and Anycubic.
- Warping: corners lifting off the bed with ABS, ASA, PETG and PLA
Why corners curl and how to reduce it: plate cleaning, drafts, enclosure, bed temperature, brim and ears, cooling and glue. Based on official guidance from Bambu Lab and Prusa and on user experience.
- Clogged nozzle and under-extrusion: find where the blockage is and fix it
How to tell a blockage in the PTFE tube, the extruder or the hotend apart, when to use the needle and cold pull, how to recognise heat creep, and when replacing the nozzle, PTFE tube or gears is actually justified.
- Wet filament: recognise it, dry it and store it
Symptoms of filament that has absorbed moisture, the most sensitive materials, how to dry following Bambu Lab and Prusa official tables without damaging spool or filament, and how to keep it dry.
- Stringing and oozing: how to get rid of filament strings and blobs
How to recognise stringing and oozing, the main causes (wet filament, temperature, retraction, travel moves, nozzle) and the checks to do in order, with official guidance from Prusa, Bambu Lab, Creality and Elegoo.
- Layer shifting: causes and checks in order
Why layers shift along X or Y and how to find the cause: obstructions, collisions with curled parts, belts, pulleys, speed, electronics cooling and motors, with official guidance from Prusa, Bambu Lab, Creality, Elegoo and Anycubic.
- Ringing and ghosting: getting rid of ripples on FDM print walls
What ringing (or ghosting) is, why it appears after corners and lettering, and how to fix it in order: printer surface, loose parts, belts, lubrication, vibration calibration (input shaping), speed and acceleration.
Dates and news
-
The Original Prusa MK4S arrives
Prusa Research launched the MK4S with redesigned 360° cooling and higher speeds, shipping immediately as assembled, kit and MMU3 bundle. Unshipped MK4 orders were converted to MK4S, and an MK4-to-MK4S upgrade kit was announced at US$99 / €109.
Sources: The Original Prusa MK4S is here (Prusa Research)
Official documentation
Manuals and guides published by Prusa Research. Links go to the manufacturer’s site; we consulted them on the date shown.
- Support page
-
- Support hub (Knowledge Base) — English, accessed on October 5, 2026
- User manual
-
- MK4S, MK3.9S — user manual (3D Printing Handbook 1.01, PDF) — English, accessed on October 5, 2026
- Assembly
-
- Kit assembly manual (1.01) — English, accessed on October 5, 2026
- Maintenance
-
- Prusa Research, 4 models — regular maintenance — English, accessed on October 5, 2026
- Printer maintenance category — English, accessed on October 5, 2026
- Prusa Research, 8 models — belt tension adjustment — English, accessed on October 5, 2026
- Troubleshooting
-
- QR error codes — English, accessed on October 5, 2026
- MK4S, MK3.9 — hotend thermal runaway error #26204 — English, accessed on October 5, 2026
- Print fan error #26816 — English, accessed on October 5, 2026
- Parts replacement
-
- MK4S, MK3.9S — Prusa Nozzle replacement — English, accessed on October 5, 2026
- MK4S, MK3.9S — hotend assembly replacement — English, accessed on October 5, 2026
- MK4S, MK3.9S — print fan replacement — English, accessed on October 5, 2026
- Firmware and software
-
- Firmware and downloads — English, accessed on October 5, 2026
- Technical specifications
-
- Official documentation — English, accessed on October 5, 2026
Sources
- Original Prusa MK4S — official documentation — Prusa Research, accessed on October 5, 2026