QIDI Max4 vs Plus4: Which Heated-Chamber Printer Should You Buy?

The QIDI Plus4 and QIDI Max4 are two enclosed CoreXY FDM printers with an actively heated chamber up to 65°C: both run a 370°C hotend and a 120°C bed, and both handle engineering materials like ABS, nylon, and carbon-fiber composites. The difference is size and price: the Plus4 gives you a 305×305×280 mm build volume for $649, while the Max4 offers 390×390×340 mm, higher speed, and factory HEPA filtration for $1099.

The Short Answer: Which QIDI to Get

In short: get the QIDI Plus4 if you want a heated chamber and high-temp materials on a budget and you don't print parts bigger than 30 cm. Get the QIDI Max4 if you need the large format, top speed, and factory filtration out of the box — and you're ready to pay more, make room, and give it a dedicated power circuit. We covered both machines in depth in our Plus4 review and Max4 review.

Spec Comparison

Build and Hardware

Both machines use a steel CoreXY gantry inside metal-look panels, with a glass lid and door. But under the hood they're two different generations. The Plus4 runs classic stepper motors with TMC2240 drivers — and that's its known weak spot: under load the drivers hit 90–100°C (confirmed by both Notebookcheck and the Russian-language 3DIY review), which can cause skipped steps and controller reboots. The fix is a mainboard cooling mod — we cover it in the Plus4 known issues guide.

The Max4 is newer and more serious mechanically: closed-loop (FOC) motors, wide 1.5GT 10 mm belts, and a linear rail on the X axis. Both printers use dual independent lead screws on Z, which helps keep the bed level across the whole area. There are no reports of driver overheating on the Max4 — a mix of different electronics and better cooling.

The Heated Chamber — Why You'd Buy Either One

The actively heated chamber is the main reason to buy either of these printers. It holds a stable temperature around the part (up to 65°C), which dramatically reduces warping and improves layer bonding on fussy materials like ABS, ASA, and nylon. The difference between models is heater power and generation: the Plus4 uses a 400 W PTC (2nd gen), the Max4 a 500 W unit (3rd gen), since it has to heat almost double the volume. In practice both reach working temperature in 5–8 minutes.

Print Quality

Both machines print well. In 3DPrint.com's tests the Plus4 hit 100.12 / 100.13 / 99.99 mm cubes with zero tuning — parts come out flat and square. On iXBT's calibration cube the Max4 showed 0.01–0.03 mm deviations, with no Z-banding and no ghosting on complex surfaces. One caveat: on very large parts the Max4 accumulates dimensional drift (up to −0.33 mm at 145 mm on X) — scale-compensate big models in the slicer. The Plus4, meanwhile, often needs temperature tuning out of the box: defaults give middling results, so expect to fiddle a bit.

Both are strong with engineering materials: the hot nozzle and heated chamber let them run polycarbonate, nylon, PA-CF, and PPS-CF. Just remember to dry your filament — carbon-fiber composites and nylon soak up moisture especially fast (which material for which job is in our filament guide). The first layer over a big area needs care, too: the Max4's 390 mm bed has a slight temperature gradient toward the edges (general tips in our first layer guide).

Speed and Throughput

The Max4 is clearly ahead here. Its real print speed is up to 600 mm/s, with 30,000 mm/s² acceleration and up to 40 mm³/s flow; it prints a PLA Benchy in about 18 minutes. The Plus4 is more modest: real print speed is 250–350 mm/s (the marketed 600 mm/s is travel, not extrusion), acceleration is 20,000 mm/s², and flow is around 25–30 mm³/s. For most household jobs the Plus4 is plenty fast, but if you're running large batches, the gap is noticeable.

Noise

The Plus4 is fairly quiet when closed — around 60 dB, up to 63 dB at high speeds. The Max4 is also calm in normal mode (56 dB), but switch on the optional Polar Cooler for fast PLA and the noise jumps to 62 dB; AppleInsider compared it to "an angry Roomba in the room with you." Add the QIDI Box and it climbs a little more — up to 65 dB.

Software and Ecosystem

Here the printers are near-twins, and that's a good thing. Both run open Klipper firmware with the Fluidd web interface — you can control them from a browser, dig into the configs, and skip the jailbreak hassle you get with Bambu Lab. The stock slicer is QIDI Studio (a Bambu Studio / OrcaSlicer fork), but nothing stops you from using vanilla OrcaSlicer or PrusaSlicer. There's no mandatory cloud: you can run everything on your local network.

Multicolor Printing: QIDI Box

Neither the Plus4 nor the Max4 has built-in multicolor — but both work with the QIDI Box add-on. It's QIDI's answer to Bambu Lab's AMS: 4 spools per module, up to 16 in a chain, NFC recognition, and automatic spool switching. The QIDI Box's key advantage is active filament drying during printing (a sealed chamber holds 65°C), which is a big deal for nylon and composites. Keep in mind: single-nozzle multicolor spends time and plastic on purging — that three-color Optimus Prime took about 14 hours on the Max4 versus roughly 2 hours in a single color.

Price and What You Get

The Plus4 starts at $649 (top config up to $799); the Max4 is $1099, and the Combo with the QIDI Box is $1249. For that near-double price, the Max4 gives you twice the build volume, noticeably higher speed, factory HEPA filtration, and heftier mechanics. The Plus4, meanwhile, is essentially the same high-temp capability in a compact body for far less money. Notebookcheck flat-out calls the Plus4 a rival to the pricier Bambu Lab X1C.

Verdict: Plus4 or Max4?

QIDI Plus4 is the smart-money pick. If you want a heated chamber for ABS, ASA, and composites and you print parts up to 30 cm, the Plus4 covers almost everything for less. Budget an evening for a driver-cooling mod and you get a near-professional printer at a hobbyist price.

QIDI Max4 is the pick for size and throughput. Big enclosures, helmets, whole functional parts, batch printing, factory filtration for engineering materials — that's all Max4 territory. But it costs more, weighs more (40 kg), is louder with the Polar Cooler, and needs a dedicated power circuit. If you don't need the large format, there's no reason to overpay. If you do, it's one of the best enclosed printers in its size class.

FAQ

Sources

• QIDI Tech — official product pages for Max4 and Plus4
• Tom's Hardware — QIDI Plus4 review
• 3DPrint.com — Plus4 test (300+ hours, accuracy, safety)
• AppleInsider — Max4 review (4.5/5)
• iXBT Live — Max4 review with accuracy tests
• Notebookcheck — Plus4 test (drivers, filtration)
• QIDI Plus4 Community Wiki — mainboard and driver cooling