Nozzle Notes

Original Prusa MK4S vs Bambu Lab A1

Two open printers: the MK4S has Prusa's load-cell levelling and a 120 °C bed, the A1 has the larger bed.

Original Prusa MK4S

Prusa Research product page
Bambu Lab A1 open-frame 3D printer with the AMS lite multi-colour filament feeder and green and blue spools on a pale blue background

Bambu Lab A1

Bambu Lab product page

Short verdict

Both are open printers. The A1 has the larger build volume at 256 x 256 x 256 mm (16.8 L) against 250 x 210 x 220 mm (11.6 L), and it weighs 8.3 kg against 7 kg for the MK4S. The MK4S lists a 120 °C bed against 100 °C, and a 290 °C nozzle against 300 °C on the A1.

Prusa publishes no maximum speed or acceleration for the MK4S, so those rows cannot be compared. Multicolour is an add-on on both: the optional MMU3 on the MK4S (up to 5 colours) or the AMS lite on the A1 (up to 4). The A1 lists a built-in camera and the MK4S does not.

Based on published specs only. We have not tested either printer.

Specs side by side

SpecificationOriginal Prusa MK4SPrusa ResearchBambu Lab A1Bambu Lab
Design
Motion systemNot publishedCartesian (bed moves on Y axis, toolhead on X)Wiki: "utilizes a Cartesian coordinate motion system"; heatbed slides on the Y-axis rail.
EnclosedNoSold open-frame; the maker offers a separate optional Enclosure accessory.NoStore FAQ cites the "open-frame design" and says "We don't recommend enclosing the A1".
Build volume (mm)250 x 210 x 220256 x 256 x 256
Build volume (litres)11.6 L16.8 LHigherComputed from 256 x 256 x 256.
Weight7 kgListed under 'Printer dimensions (without spool)': 7 kg, 500x550x400 mm.8.3 kgNet weight of the A1 (without AMS lite).
Printing
Max nozzle temperature290°C300°CHigher
Max bed temperature120°CHigher100°C
Max print speedNot published500 mm/sMaker lists this as "Max Speed of Tool Head".
Max accelerationNot published10000 mm/s²Maker lists this as "Max Acceleration of Tool Head".
Standard nozzle0.4 mmHigh-flow Prusa Nozzle brass CHT.0.4 mmStainless steel; 0.2, 0.6 and 0.8 mm also offered.
Features
Multicolour / multi-materialOptional MMU3 add-on, up to 5 coloursAMS lite (A1 Combo), up to 4 coloursStore FAQ: only one AMS lite supported, max 4 colours; AMS / AMS 2 Pro / AMS HT possible via the AMS HUB accessory.
Bed levellingAutomatic mesh bed levelling (print area only), Loadcell sensorAutomatic: nozzle-contact probing, 7 x 7 grid (49 points) height map
Built-in cameraNoMaker lists the camera as an optional standalone add-on.YesLow frame rate camera (up to 1080P), timelapse supported.
Screen3.5-inch graphic 65k colour screenNot publishedMaker pages call it a touchscreen but give no size.
ConnectivityEthernet, NFC receiver, removable ESP Wi-Fi module, USB driveWi-Fi and Bluetooth (mainboard SoC); Bambu Cloud or LAN-only modeWiki describes the SoC as having Wi-Fi and Bluetooth basebands; the store page lists Bambu Cloud and LAN-only mode.
Filament runout sensorYesYes
LaunchedNot publishedNot publishedNot stated on the maker pages checked.

Specs checked against the maker's pages on 2026-10-10. Want a different pairing? Open this in the comparison tool to add a third printer.

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