Elegoo Neptune 4 Pro: The Klipper Bedslinger, Assessed
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The Neptune 4 Pro is a 225 × 225 × 265 mm open bedslinger running Klipper, with a 300 °C direct-drive hotend, 110 °C bed, 500 mm/s rated speed and 121-point auto levelling. It was the budget speed champion of its year. In 2026 it competes with the Ender-3 V3 KE and the Bambu A1 mini, and Amazon US stock has thinned. This page is based on manufacturer data and owner reports.
Where to buy
Specifications
| Item | Value | Note |
|---|---|---|
| Build volume | 225 × 225 × 265 mm | |
| Max nozzle temperature | 300 °C | Dual-gear direct drive |
| Max bed temperature | 110 °C | Segmented heatbed: heat only the centre for small parts |
| Speed / acceleration | 500 mm/s / 20000 mm/s² | Practical 150 to 250 mm/s |
| Levelling | Auto, 121 points | Manual Z-offset |
| Cooling | Dual 4015 part fans plus four 4020 auxiliary fans | Strong for PLA overhangs |
| Firmware | Klipper | Input shaping, pressure advance |
| Plate | Dual-sided PLA surface / textured PEI |
What it does well
- PLA at speed. The auxiliary fan bank is unusual at the price and shows in overhangs.
- Bed levelling. 121 points and a segmented heater that can warm just the middle of the bed for small parts.
- Klipper out of the box, with a real mainline-Klipper path for owners who want it.
Weak spots
- Open frame and 300 °C: PLA, PETG, TPU. Not an ABS machine.
- Manual Z-offset and occasional first-layer inconsistency on the stock firmware; see bed levelling.
- Elegoo’s stock Klipper build lags upstream; many owners flash community firmware.
In 2026
The Ender-3 V3 KE matches its speed class with a more active spares ecosystem, and the Bambu A1 mini beats it on automation at a smaller size. The Neptune 4 Pro remains a good buy if found at a low price and you are comfortable with Klipper. Elegoo’s own line has moved to the enclosed Centauri Carbon. See the KE page for the direct rival.
The units in the box
Neptune 4 Pro listings on Amazon US are inconsistent. Shown are the current Neptune 4 listing, the Neptune 3 Pro that preceded it and the Ender-3 V3 KE as the direct competitor.
FAQ
Neptune 4 or 4 Pro? Same size; the Pro adds the dual-gear extruder, more cooling and the segmented bed.
Can it print carbon fibre? After a hardened nozzle swap.
LayerWalker
Print defect diagnosis, calibration procedures and parts that actually fit. Corrections welcome through the contact page.
