Why has FDM print speed increased so dramatically in the last two years?

FDM printers from 2020 and earlier were largely built around Cartesian motion systems — where either the print bed or the print head moves on a single axis at a time. These systems have mechanical limits on how fast they can accelerate and decelerate without producing vibration artefacts (ghosting or ringing) in the finished print.

The speed jump in current-generation machines comes from two changes arriving together. First, the widespread adoption of CoreXY motion systems — where two motors drive the print head simultaneously in X and Y, dramatically reducing the moving mass and allowing much higher acceleration. Second, input shaping algorithms in the printer's firmware that actively compensate for vibration at high speeds, allowing the machine to print fast without the quality degradation that high speeds previously produced.

The combination of these two changes — CoreXY hardware plus input shaping firmware — is what separates the current generation of high-speed printers from the machines that came before them. It's a genuine capability improvement, not a marketing number inflated by looser definitions.

What does the rated speed figure actually mean in practice?

The rated maximum speed — 500mm/s on the Neptune 4 Pro, for example — is the peak speed the print head can travel in open straight lines. Real-world print jobs are not a series of open straight lines. They consist of curves, sharp corners, overhangs, infill patterns, and perimeters at varying sizes — each of which requires the printer to accelerate and decelerate rather than maintain peak speed throughout.

In practice, most hobbyist prints run at an average of 40–60% of the printer's maximum rated speed. A printer rated at 500mm/s will typically produce average print speeds in the 200–300mm/s range across a full print job — which is still dramatically faster than the 60–80mm/s average of an older entry-level machine.

The practical impact is significant. A print that took 8 hours on an older machine takes 3–4 hours on a current high-speed machine. Over dozens of prints per month, this compounds into genuinely reclaimed time.

Where does the ELEGOO Neptune 4 range sit in the current speed landscape?

Is speed worth paying for — or is it mostly marketing?

Speed is worth paying for under specific conditions. If you print infrequently — a few objects per month — the time saving per print is real but not life-changing. A 4-hour job versus an 8-hour job matters more if you're printing 20 jobs per month than if you're printing two.

Speed becomes genuinely valuable when you're producing multiple parts in a session, running a print service for others, prototyping iteratively (where the sooner you have the result in hand, the sooner you can iterate), or working to deadlines. The Neptune 4 series hits the price-to-performance point where the speed improvement over older entry machines is meaningful and the cost premium over those machines is justifiable.

Frequently asked questions about high-speed FDM printing