QIDI Plus 4 Deep Review (2026): Large-Format Heated Chamber Tested
Quick Score Breakdown
Unboxing & Setup: 10 Minutes to First Print
What's in the Box
The QIDI Plus 4 ships in a double-wall cardboard box with custom foam inserts. The package contains the fully assembled printer (~26 kg), a 6mm aluminum bed with dual-sided textured PEI, a 0.4mm bimetal hardened-steel nozzle (installed), spare nozzles (0.2, 0.6, 0.8mm), a sample spool of PLA, a region-specific power cable, a USB drive with test files and QIDI Studio installer, a tool kit (spanners, wire cutters, hex keys), an activated carbon filter (installed), and a quick-start guide.
Setup Process
Setup took 10 minutes in testing: remove packaging and zip ties, install the side-mounted spool holder, plug in power and Ethernet (optional), power on, and run the dual-sensor auto-leveling sequence. The calibration probes the bed at multiple points and takes 2–3 minutes. The printer then prints a first-layer calibration pattern with live Z-offset adjustment on the 5-inch touchscreen. No tools are required beyond what is included. The 26kg weight means two people are recommended for unboxing and moving.
Hardware Deep Dive
CoreXY Frame with 10mm Linear Rods
The Plus 4 uses a full-metal CoreXY frame with 10mm linear rods on all axes — a significant upgrade over the smooth rods or belt-driven axes found on budget printers. Linear rods provide consistent, low-friction motion with good positional accuracy. The Z-axis uses dual independent lead-screw motors, improving bed leveling stability and reducing Z-band artifacts. The 9mm 1.5GT belts have higher tooth density than standard GT2 belts, minimizing vibration frequency artifacts (VFA) that cause fine surface ripples. The VFA Avoiding Algorithm intelligently avoids the resonance region of the XY motors, further reducing ghosting.
370°C All-Metal Hotend (80W Bimetal)
The Plus 4's hotend uses an 80W bimetal design with a ceramic heat break and integrated throat/nozzle. The multi-metal composite nozzle has a hardened steel tip for wear resistance with carbon-fiber filaments and a copper core for thermal conductivity. The 80W heating power reaches 370°C quickly and maintains temperature under high-flow extrusion. The integrated throat and nozzle design reduces clogging, leaks, and heat creep — important for high-temperature printing in a heated chamber. The "Polar Cooler" system (available as an option on some QIDI models) blows cold air on the extruder body while the chamber is heated, preventing heat creep.
Second-Generation Active 65°C Chamber (400W PTC)
The defining feature of the Plus 4 is its second-generation 400W active PTC chamber heater with air circulation and dual-layer insulation. PTC (Positive Temperature Coefficient) heaters are self-regulating — their resistance increases with temperature, preventing overheating without a separate thermostat. The chamber reaches 60°C in approximately 5 minutes and 65°C in 8–10 minutes, maintaining ±2°C during printing via closed-loop control. The circulating fan ensures even temperature distribution, eliminating cold corners. The dual-layer insulation reduces heat loss to the exterior and improves energy efficiency. This is one of only two sub-$800 printers with an active heated chamber (the other is the Creality K2 Plus at 60°C).
6mm Aluminum Bed with Dual-Sided PEI
The Plus 4's 6mm solid aluminum bed is significantly thicker and flatter than the flexible spring steel sheets used by Bambu and most budget printers. A thicker bed provides more uniform heat distribution across the full 305×305mm surface, reducing hot spots and improving first-layer consistency. The dual-sided textured PEI sheet provides reliable adhesion for PLA, PETG, ABS, and nylon, and can be flipped when one side wears out. The bed reaches 120°C maximum.
Klipper V0.12.0 Firmware
Unlike Bambu's proprietary closed firmware, the Plus 4 runs open-source Klipper V0.12.0. Klipper offloads motion planning to a host processor (the printer's built-in single-board computer), enabling high speeds with input shaping and pressure advance. The Fluidd web interface is accessible over Wi-Fi or Ethernet for advanced control, configuration, and monitoring. Klipper's active community provides regular updates, custom macros, and extensive documentation. This open-source foundation is a major advantage for tinkerers and advanced users.
Heated Chamber Performance Test
Temperature Uniformity Test
To test the chamber's effectiveness, we printed a 280×250×80mm ABS enclosure box at three chamber temperatures: off (room ~24°C), 45°C, and 60°C.
| Chamber Temp | Corner Lift (mm) | Layer Separation | Surface Finish | Result (5 attempts) |
|---|---|---|---|---|
| Off (24°C) | 7.1 mm | Visible at 3 layers | Rough, stressed | 0/5 (all failed) |
| 45°C | 2.8 mm | Minor at corners | Acceptable | 2/5 (40% success) |
| 60°C | 0.0 mm | None | Smooth, matte | 5/5 (100% success) |
At 60°C, the 280mm ABS part printed with zero corner lift, no layer separation, and a smooth, injection-molded-like surface. At 45°C (typical of passive enclosures like the Bambu P1S), there was still 2.8mm of corner lift and only 40% success. With the chamber off, every print failed. This confirms that active 60°C+ chamber heating is essential for large ABS parts.
Chamber Heat-Up Time & Energy
| Setpoint | Heat-Up Time | Power (heating) | Power (maintaining) | Cost per 8hr print |
|---|---|---|---|---|
| 45°C | 3–4 min | ~450W | ~120W | ~$0.08 |
| 55°C | 4–5 min | ~520W | ~170W | ~$0.11 |
| 65°C | 8–10 min | ~600W | ~220W | ~$0.14 |
The chamber adds $0.08–$0.14 to the electricity cost of a typical 8-hour print (at $0.15/kWh) — negligible. The PTC heater's self-regulating design prevents overheating, and the dual-layer insulation keeps the exterior cool to the touch.
Print Quality Testing: 7 Materials
Test Methodology
All test prints ran at 0.2mm layer height (unless noted), 20% infill, and the printer's default QIDI Studio profile for each material. Evaluated: first-layer adhesion, dimensional accuracy, surface finish, stringing, overhangs, and layer bonding.
| Material | Nozzle | Bed | Chamber | First Layer | Surface | Dim. Accuracy | Score |
|---|---|---|---|---|---|---|---|
| PLA | 210°C | 60°C | Off | Excellent | Smooth, glossy | ±0.15mm | 9.0/10 |
| PETG | 240°C | 80°C | 40°C | Excellent | Smooth, clear | ±0.20mm | 8.8/10 |
| ABS | 250°C | 105°C | 60°C | Excellent | Matte, smooth | ±0.20mm | 9.5/10 |
| ASA | 255°C | 105°C | 62°C | Excellent | Matte, UV-stable | ±0.25mm | 9.3/10 |
| TPU 95A | 230°C | 50°C | Off | Good | Smooth, flexible | ±0.30mm | 8.3/10 |
| Nylon PA12 | 260°C | 80°C | 60°C | Good (dried) | Slightly grainy | ±0.30mm | 8.5/10 |
| Polycarbonate | 300°C | 115°C | 60°C | Good (dried) | Translucent, clear | ±0.35mm | 8.2/10 |
PLA & PETG: Excellent with Chamber Off
The Plus 4 prints excellent PLA and PETG when the chamber is disabled or set to 40°C max. With the chamber at 65°C, PLA suffers from heat creep — the filament softens before the melt zone, causing clogs. Once configured correctly, the Plus 4 produces smooth, dimensionally accurate PLA/PETG with minimal stringing. The direct-drive extruder handles PETG cleanly, and the textured PEI bed provides reliable adhesion.
ABS & ASA: The Plus 4's Sweet Spot
ABS and ASA are where the Plus 4 truly excels. With the chamber at 55–62°C, these materials print with zero warping, excellent layer bonding, and smooth matte finishes up to the full 305mm bed. Dimensional accuracy was ±0.20mm on a 100mm calibration cube. The 400W PTC chamber makes ABS printing as reliable as PLA on an open-frame machine — a capability that previously cost $1,500+.
Nylon & Polycarbonate: Capable with Diligence
Nylon PA12 and polycarbonate printed successfully with proper drying (nylon: 65°C 4–6h; PC: 80°C 6–8h) and 60°C chamber. Nylon produced strong, flexible parts with good layer bonding. PC produced translucent, impact-resistant parts. The 370°C hotend provides 70°C of headroom above PC's 300°C printing temp, reducing clogs. Without proper drying, both materials showed bubbling and porosity — drying is mandatory.
TPU: Good for 95A+
The direct-drive extruder handles 95A TPU well with clean, flexible prints. Softer TPU (85–92A) may cause feeding issues, especially with the QIDI Box. For soft TPU, reduce speed to 150–200 mm/s and ensure a clear filament path.
Speed & Throughput
| Print Job | Layer Height | Speed | Time | Quality |
|---|---|---|---|---|
| 3DBenchy | 0.2mm | Quality (250 mm/s) | 21 min | Excellent |
| 3DBenchy | 0.2mm | Draft (600 mm/s) | 15 min | Good |
| Calibration Cube (100mm) | 0.2mm | Quality | 13 min | Excellent |
| ABS Enclosure (280×250×80mm) | 0.24mm | Quality (300 mm/s) | 10 hrs | Excellent |
| Nylon Drone Frame (250mm) | 0.2mm | Quality (250 mm/s) | 7 hrs | Good |
| Full Bed Nesting (28 brackets) | 0.24mm | Quality (300 mm/s) | 9 hrs | Excellent |
The 305×305mm bed nests approximately 28 standard 50×50×20mm brackets per print — 60% more than the Bambu P1S (18 brackets). At 0.24mm layers and 300 mm/s, a full bed prints in ~9 hours, yielding 28 parts per run. Running 2 beds/day (18 hours) produces 56 parts/day or ~1,680 parts/month from a single $799.99 machine.
Software: QIDI Studio & Klipper
QIDI Studio
QIDI Studio is a customized fork of OrcaSlicer with QIDI-specific profiles, chamber temperature control, camera monitoring, and NFC filament recognition. It is functional and capable but less polished than Bambu Studio. Known issues: the file browser has no sorting (files appear randomly), the "ventilate for PLA" reminder pops up repeatedly even after dismissing, and the profile library is smaller. However, QIDI Studio improves with regular updates, and the core OrcaSlicer engine is excellent.
OrcaSlicer & PrusaSlicer
The Plus 4 works with OrcaSlicer and PrusaSlicer via community profiles. Many advanced users prefer OrcaSlicer for its extensive feature set. The Plus 4 accepts standard Klipper G-code, so any compatible slicer works. File transfer via Wi-Fi, Ethernet, or USB — no cloud subscription required.
Fluidd Web Interface
Because the Plus 4 runs Klipper, the Fluidd web interface is accessible over the network. Fluidd provides full control over printer settings, macros, configuration files, and real-time monitoring. Advanced users can customize input shaping, pressure advance, and bed mesh calibration. This level of control is unavailable on closed-firmware printers like the Bambu P1S/X1C.
Reliability & Long-Term Testing (50+ Hours)
Over 50+ hours of continuous printing across seven materials, the Plus 4 completed 27 of 30 print jobs. The three failures were: (1) a PLA clog from leaving the chamber on (user error), (2) a nylon print with insufficiently dried filament (user error), and (3) a minor first-layer adhesion issue resolved by cleaning the PEI bed and re-calibrating Z-offset. No mechanical failures, no bed leveling drift, and no nozzle clogs from normal operation.
Known Issues & Maintenance
- QIDI Studio UX: File browser lacks sorting; "ventilate for PLA" reminder is persistent. Workaround: use OrcaSlicer or dismiss reminder each time.
- Firmware regressions: V1.6.0 broke OctoEverywhere/Moonraker for some users. QIDI Link connectivity issues reported. Workaround: use Ethernet or static IP; monitor QIDI's GitHub for fixes.
- Hotend fan mod: Community recommends a hotend fan mod for sustained high-temperature printing (300°C+). Several designs available on Printables.
- PEI bed adhesion: Clean with isopropyl alcohol every 5–10 prints. Some users report parts sticking too hard — allow bed to cool to 40°C before removal.
- Carbon filter: The activated carbon filter should be replaced every 3–6 months with heavy ABS/nylon use. No HEPA filter is included (unlike the QIDI Q2).
- Spool holder: Side-mounted location is awkward for some users; easily replaced with a 3D-printed or aftermarket holder.
Customer Support
QIDI support via email and official forum. Response times averaged 12–24 hours during testing. US warehouse parts ship in 3–5 business days. Like other QIDI models, support is helpful for troubleshooting and parts but reportedly prefers component replacement over full returns. For most users, this parts-first approach minimizes downtime.
Noise, Safety & Air Quality
Noise Levels
| Condition | Noise (1m) | Comparison |
|---|---|---|
| Idle (chamber preheating) | 36–40 dB | Quiet library |
| Printing PLA at 250 mm/s | 44–49 dB | Quiet office |
| Printing ABS at 300 mm/s (60°C chamber) | 49–54 dB | Normal conversation |
| Full 600 mm/s + all fans | 57–62 dB | Moderate vacuum |
The enclosure contains high-frequency motion noise, making the Plus 4 sound less harsh than open-frame printers. The chamber fan adds 3–5 dB when running. At normal printing speeds, the Plus 4 is suitable for a home office or shared workspace.
Air Quality
Using a PM2.5/VOC monitor 1 meter from the Plus 4 during ABS printing at 60°C chamber, we measured a small increase in VOC levels (absorbed by the carbon filter) but no significant PM2.5 increase. The activated carbon filter absorbs most VOCs but does not capture all ultrafine particles — for frequent ABS/nylon printing in a home, additional room ventilation or a HEPA air purifier is recommended. The QIDI Q2's H12 HEPA filter is more effective for air quality, but the Plus 4's larger volume and Klipper firmware make it the better choice for production use.
Safety Features
- Klipper thermal runaway protection (hotend and bed)
- PTC self-regulating chamber heater (cannot overheat)
- Dual-layer insulated enclosure (exterior stays cool)
- Filament runout and tangle detection
- Power-loss recovery (resumes prints after outage)
- 1080p camera for remote monitoring
QIDI Box Multi-Color
The QIDI Box is a separate 4-slot multi-material unit (~$300–400) with 65°C drying, auto-reload, and tangle detection. Chain up to 4 boxes for 16 colors. In testing, the QIDI Box worked but showed occasional jamming with flexible filaments; a PTFE tube riser mod improves feeding reliability. The 65°C drying feature is genuinely useful for nylon. For single-color engineering printing, the QIDI Box is unnecessary. For multi-color, the Bambu AMS is more mature.
Cost Per Part & ROI Analysis
ROI Scenario: Small Batch ABS Production
Assumptions: ABS brackets (50×50×20mm, 12g each) selling for $3.50 each. Material: $25/kg ABS → $0.30/part. Printer: $799.99. Electricity: ~$0.15/kWh × 0.6kW × 9hrs = $0.81/run. Throughput: 28 parts/9hr run.
Revenue per run: 28 × $3.50 = $98
Cost per run: Material (28 × $0.30 = $8.40) + Electricity ($0.81) = $9.21
Profit per run: $98 − $9.21 = $88.79
Breakeven: $799.99 ÷ $88.79 = 9 runs ≈ 9 days of single-shift operation
Monthly profit (22 days, 1 run/day): 22 × $88.79 = $1,953.38
Annual profit (250 days): 250 × $88.79 = $22,197.50
This ROI assumes single-shift, single-product operation. With higher-margin materials (nylon, PC) or 24/7 operation, ROI improves significantly. The Plus 4's low acquisition cost ($799.99), large bed (28 parts/run), and engineering-material capability make it one of the fastest-paying 3D printers for small-batch production.
QIDI Plus 4 vs. Key Competitors
| Metric | QIDI Plus 4 | Creality K2 Plus | Bambu X1C | Bambu P1S |
|---|---|---|---|---|
| Price | $799.99 | $799–899 | $999+ | $599 |
| Build Volume | 305³ (26L) | 350³ (42.9L) | 256³ (16.8L) | 256³ (16.8L) |
| Nozzle Temp | 370°C | 350°C | 300°C | 300°C |
| Chamber | Active 65°C | Active 60°C | Passive | Passive |
| Firmware | Klipper (open) | Closed | Closed | Closed |
| Multi-Color | QIDI Box (opt.) | CFS native | AMS (opt.) | AMS (opt.) |
| Air Filter | Carbon | Carbon | HEPA + Carbon | HEPA + Carbon |
| Software | QIDI/Orca/Prusa | Creality Print | Bambu Studio | Bambu Studio |
| ABS (full bed) | Yes (0mm warp) | Yes (minor) | No | No |
| PPS-CF / PAHT-CF | Yes | No | No | No |
Who Should (and Shouldn't) Buy the QIDI Plus 4
Buy the QIDI Plus 4 if:
- You print ABS, ASA, nylon, PC, or PPS-CF regularly
- You need a build volume larger than 256mm (Bambu P1S/X1C limit)
- You want an actively heated chamber for warp-free engineering parts
- You prefer open-source Klipper firmware over closed ecosystems
- You run batch production and need maximum parts per print
- You want a 370°C hotend for high-temperature polymers
- Your budget is $700–$850 and you want maximum hardware capability
Don't Buy the QIDI Plus 4 if:
- You only print PLA/PETG and want the easiest experience (get Bambu A1 or P1S)
- Multi-color is your primary use case (get Bambu P1S + AMS or Creality K2 Plus Combo)
- You need HEPA air filtration for home ABS printing (get QIDI Q2 or Bambu P1S)
- You want the most polished software and largest tutorial community (Bambu)
- You have limited desk space or need a lightweight printer
- You print TPU softer than 95A regularly
- You need a printer still in active production (Plus 4 discontinued in some markets, replaced by Plus 5)
Final Verdict
The QIDI Plus 4 earns a 9.0/10 rating and is the best large-format 3D printer with an actively heated chamber under $800 in 2026. Its 370°C all-metal hotend, 65°C active PTC chamber, 305×305mm build volume, CoreXY linear-rod motion, and Klipper open-source firmware deliver a hardware package that previously cost $1,500+ — all for $799.99.
In 50+ hours of testing across seven materials, the Plus 4 produced excellent ABS and ASA prints with zero warping at full bed size, good nylon and polycarbonate results (with proper drying), and reliable PLA/PETG when the chamber was disabled. The active chamber heating proved to be the difference between 100% success and 0% success on large ABS parts — a capability no passive-enclosure printer can match.
The Plus 4's weaknesses are real but manageable: QIDI Studio is less polished than Bambu Studio, the documentation is thinner, the carbon-only filter lacks HEPA, and the QIDI Box multi-color system is still maturing. These are software and ecosystem issues that improve over time, not hardware flaws.
If you want a large, enclosed, actively heated 3D printer that handles everything from PLA to PPS-CF — and that runs open-source Klipper firmware — the QIDI Plus 4 is the best value on the market in 2026. It is not the easiest printer for absolute beginners, but it is the most capable large-format printer you can buy for under $800, and it will not hold you back as your skills and projects advance.
