Neptune 4 vs Neptune 4 Max: Differences and Verdict

The Elegoo Neptune 4 and Neptune 4 Max share a name, Klipper firmware and a claimed top speed of 500 mm/s, but in day-to-day use they are two very different machines. The difference is not just that one is bigger. They differ in hotend construction, bed heater power and maximum bed temperature, network connectivity and, above all, in how much space, table stability and calibration patience they demand. Choosing between them is not a budget question, it is a question of what you will actually print. This guide compares build volume, temperature limits, connectivity and the practical realities of running each machine, and ends with a concrete recommendation based on the kind of projects you have in mind.

What is the main difference between the Neptune 4 and Neptune 4 Max?

The base Neptune 4 has a build volume of 225 x 225 x 265 mm, roughly 13.4 liters. The Neptune 4 Max offers 420 x 420 x 480 mm, which works out to about 84.7 liters. So the gap is not double or triple, it is roughly sixfold. That matters, because when people compare printers they tend to look at a single dimension instead of working out how many parts will fit on the plate in a batch.

The two models have more in common than a first glance suggests. Both run Klipper firmware, both use a dual gear direct drive extruder, both come with a magnetic PEI plate and 121-point automatic bed leveling combined with manual fine-tuning via the knobs, and both handle nozzle temperatures up to 300 °C. Structurally, both are classic Cartesian machines with the bed moving along the Y axis, the so-called bed slinger layout.

Pricing across the range runs from roughly $299 for the Pro version to $470-550 for the Max, with the Neptune 4 Plus and its 320 x 320 x 385 mm volume sitting in between. Street prices vary by retailer and availability, but the ratio holds: expect to pay about one and a half to two times the price of the small model for the Max.

Put simply, the Max is not a better printer. It is a printer with a different purpose and a different set of trade-offs.

• Neptune 4: 225 x 225 x 265 mm, bed up to 100 °C, file transfer over LAN and USB
• Neptune 4 Plus: 320 x 320 x 385 mm, 320 W bed, WiFi
• Neptune 4 Max: 420 x 420 x 480 mm, 320 W bed capped at 85 °C, WiFi and 8 GB of internal storage
• Shared across the range: Klipper, 121-point ABL, 300 °C nozzle, a claimed 500 mm/s

How much of that bed area will you actually use?

A big build volume is easy to sell and harder to use than most first-time buyers expect. Typical hobby projects (brackets, organizers, boxes, household replacement parts, tabletop miniatures) fit comfortably within 225 x 225 mm. Model repository statistics back this up: the vast majority of freely available models are designed to fit a standard 220 mm plate, because that is the most common format on the market.

There are two situations where a large plate genuinely changes the rules. The first is printing a single large object in one piece: a helmet, a scale car model, a cabinet part, a planter or an equipment enclosure. You can always split a large object and glue it back together, but the seam is a weak point and gluing costs time. The second is batch printing, when you need forty identical parts at once and do not want to walk over and clear the plate four times a day.

Batch printing is the strongest argument for the Max. A 420 x 420 mm plate holds roughly 3.5 times as many parts as the base model, which fundamentally changes the ratio of machine time to human time in small-batch production. If you print individual parts on commission or for your own projects now and then, that advantage will never show up.

Before you decide based on dimensions, go through your last ten projects and count how many would not have fit on a 225 mm plate. If the answer is zero or one, the Max will not pay for itself. You can also compare specs across models and brands in the tool below.

Hotend and extruder: what the Max adds

A bigger build volume on its own is not enough, because large parts mean longer prints and higher demands on material flow. Elegoo addressed this on the larger models by reworking the hot zone. While the Pro version uses a bimetal heatbreak of copper and titanium, the Plus and Max use an all-titanium design with an extended hot zone, a 60 W ceramic heater and a brass heater block.

The practical impact is twofold. A stronger heater holds temperature steady at high flow rates, which is a prerequisite if you want to make even partial use of that 500 mm/s figure. The titanium heatbreak also copes better with sustained operation at higher temperatures, which is relevant for materials like ABS, ASA or nylon. The official supported filament list covers PLA, TPU, PETG, ABS, ASA and nylon.

The downside of the reworked hotend is serviceability. Changing the nozzle on the Neptune 4 Plus and Max is more involved than on the previous Neptune 3 generation, because you have to remove more parts before you reach the nozzle. On a printer you plan to feed abrasive carbon fiber composites, where nozzles are consumables, that is a real operational drawback.

Nozzle diameter and layer height affect print time on large parts more than raw speed does. Above 300 mm of footprint, switching from a 0.4 mm nozzle to a 0.6 mm nozzle often pays off more than any amount of acceleration tuning.

Heated bed: 100 °C on the small model, 85 °C on the Max

This is one of the most overlooked differences across the whole range. The Pro version, with its 225 x 225 mm bed, uses a 100 W plus 150 W heater and reaches 100 °C. The Neptune 4 Max has a far more powerful 320 W heating element, but because the surface area is many times larger, maximum bed temperature tops out at 85 °C.

For PLA and PETG that makes no difference, since both are normally printed with a bed between 60 and 80 °C. The problem shows up with ABS and ASA, where the recommended bed temperature sits around 90 to 110 °C and first-layer adhesion is critical. Printing ABS on a large open-frame printer at 85 °C means fighting warping on exactly the large parts you bought the Max for.

The fix is an enclosure, or at least a draft shield, which on a machine with a footprint over 60 cm is more expensive and more space-hungry than on the small model. Without one, the Max is primarily a PLA and PETG machine, plus PETG composites, which are less prone to shrinking.

The second issue with large beds is flatness. Reviews of big bed slingers repeatedly point out that a 420 mm aluminum plate is rarely perfectly flat, and that even 121-point mesh leveling does not always guarantee a good first layer across the whole surface. In those cases the community recommends printing the first layer with increased flow, using a raft for large-footprint parts, or fine-tuning the probe offset relative to the nozzle.

Connectivity and Klipper: the biggest convenience gap

The Neptune 4 brought Klipper firmware to the $300 price bracket, the same software that runs a substantial share of high-performance DIY printers. Reviewers criticized the base model for keeping Klipper effectively hidden, though: there is no built-in WiFi and no proper interface on the display, so an ordinary user simply cannot reach the features Klipper is used for in the first place. File transfer is limited to a LAN cable and USB.

The Neptune 4 Plus and Max have a WiFi antenna, LAN and USB, and the Max adds 8 GB of internal storage. The day-to-day difference is bigger than a single spec line suggests. Sending files wirelessly means the printer can live in a workshop, garage or basement without you walking over with a flash drive every time you tweak a model. On long prints across a big plate, which can easily run 30 hours, remote access to printer status is close to essential.

Klipper also opens up settings that standard firmware lacks: pressure advance to suppress corner bulging, input shaping to counter resonance, and the ability to monitor a print through a web interface. Pressure advance is supported across the entire Neptune 4 range.

If the openness of Klipper is what draws you in and you plan to tune the printer, the network connectivity on the Plus and Max saves a lot of frustration. On the base model you can add WiFi with an external single-board computer, but that is a project in itself and not an ideal entry point into 3D printing for a beginner.

Is 500 mm/s a real speed, or a catalog number?

Both printers list a 500 mm/s maximum. Reality is different: the Neptune 4 Max ships with defaults around 250 mm/s, and even that figure applies mostly to long straight infill paths rather than perimeters, where speed drops automatically to preserve surface quality.

Physics works against the large machine. A Cartesian design with a moving bed has to stop and accelerate the entire mass of the bed plus the print on every direction change in Y. On a 420 x 420 mm plate that mass is significantly higher than on a 225 mm plate, and with a tall, heavy part it keeps growing as the print progresses. High accelerations on large parts therefore show up as ringing and, in extreme cases, layer shifts.

The smaller Neptune 4 is friendlier to high speeds in this respect, because its moving mass is lighter and it is less prone to resonance. If you want genuinely fast printing without compromising quality, look at a CoreXY design, where the toolhead moves in both axes and the bed stays put.

In practice, you do not buy the Max for speed, you buy it because a large part comes off the plate in one piece. The time saving does not come from higher mm/s, it comes from not having to split the print into four sections and glue them together.

Living with it: table, weight, noise and power draw

This is the area spec sheets never capture, and the one that determines satisfaction most. The Neptune 4 Max is a large, heavy machine and it transmits considerable forces into whatever it sits on. Reviewers describe ordinary tables vibrating enough during printing to show up in print quality, with the printer eventually having to be moved to the floor. A concrete paving slab, a solid workbench top or an anti-vibration mat is not an optional accessory at this size.

The footprint of a machine with a 420 x 420 mm build area extends well beyond the bed itself, because the bed has to travel forward and back. The real depth of space you need is roughly twice the depth of the bed. If you are planning to put a printer on a desk in the living room, the Max is the wrong choice even before you factor in noise.

Assembly takes about half an hour on both models and follows the same pattern: mount the gantry to the base, then fit the extruder. On the larger models it is worth installing the extruder only after the gantry is secured, since the small screws are easier to reach that way.

Do not overlook power consumption. A 320 W bed heats essentially continuously, and on multi-day prints that shows up on the electricity bill. The smaller model, with its 100 W plus 150 W heater, is more modest here and easier to live with in an apartment.

• The Max needs a solid table or the floor; ordinary lightweight furniture passes vibration into your prints
• Real depth of space required is roughly twice the depth of the bed
• Assembly takes about 30 minutes; fit the extruder after the gantry
• Nozzle changes on the Plus and Max are more laborious than on the previous Neptune generation

Pros and cons of both models

The summary below covers what each model actually delivers and where its weaknesses show. No single point is disqualifying on its own, but together they add up to two distinct usage profiles.

A note on the Pro version: the base Neptune 4 and the Neptune 4 Pro share a build volume and differ in component quality, with the Pro getting a bimetal heatbreak and a split bed heater. If you are choosing in the small format, the Pro is usually the smarter buy over the base version.

• Neptune 4 pros: lower price, bed up to 100 °C and therefore better suited to ABS, lower moving mass, modest power draw, fits on a desk
• Neptune 4 cons: no built-in WiFi, Klipper is effectively inaccessible to the user, manual bed leveling is tedious, build volume limits larger projects
• Neptune 4 Max pros: 420 x 420 x 480 mm volume, WiFi and internal storage, stronger hotend with a titanium heatbreak and 60 W ceramic heater, ideal for batch printing
• Neptune 4 Max cons: bed limited to 85 °C, questionable flatness on the large plate, demanding on stable support and space, higher power draw, more laborious nozzle changes

Which model to choose, by project type

Choose the base Neptune 4 or the Pro version if you mostly print functional parts up to about shoebox size, repair parts, organizers, gaming accessories or prototypes. The smaller format gives you faster bed heat-up, a higher temperature ceiling for ABS and ASA, lower space requirements and fewer variables when dialing in the first layer. For a beginner it is the safer choice, because there are fewer mistakes to make and each one costs less in time and material.

The Neptune 4 Max makes sense in three scenarios: you print large single-piece objects where splitting and gluing would degrade the result, you regularly need to produce dozens of parts in one batch, or you have a specific project over 300 mm that you cannot solve any other way. In all three cases, expect to print mainly PLA and PETG unless you enclose the printer.

There is a middle path. The Neptune 4 Plus, with its 320 x 320 x 385 mm volume, offers the Max’s WiFi and reworked hotend with substantially lower space requirements and a lower price. For most hobby users who only occasionally hit the 225 mm wall, the Plus is a more sensible compromise than jumping straight to the Max.

If you are not sure where your projects fall, run through the printer selection quiz and compare specs across brands. Keep in mind that a large format solves one problem and adds three new ones: space, stability and the bed temperature limit.

The Neptune 4 and Neptune 4 Max are not two tiers of the same machine, they are two different briefs. The smaller model offers a higher bed temperature, easier calibration and undemanding operation at a lower price; the large one brings six times the volume and better connectivity in exchange for an 85 °C bed limit, a need for a stable surface and more laborious hotend maintenance. Practical advice: count how many of your recent projects would not have fit on a 225 mm plate. If it is fewer than a third, buy the small model and put the money you saved into a filament dryer and quality nozzles.

Affiliate link: You can buy the Elegoo Neptune 4 Max at Elegoo’s official store.