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Direct answer: do not buy the QIDI Plus4 at near-current-model money in 2026. QIDI now identifies the Plus 5 as the Plus4's direct successor and says the Plus4 is discontinued, although regional stock can remain. A verified discounted, used, or open-box Plus4 can still be the right 305 x 305 x 280 mm active-chamber machine when its condition, warranty, exact QIDI Box hardware, and smaller envelope all pass. For a normal new purchase with a modest price gap, start with Plus 5.
| Your actual workload | Plus4 fit | Why |
|---|---|---|
| Recurring parts need more than 256 mm in X or Y and benefit from enclosure control | Strong fit | The 305 x 305 mm bed can remove a measured one-piece-part bottleneck |
| ABS, ASA, nylon, or similar shrink-sensitive work is a normal queue | Good fit | The active chamber has a real job instead of being unused specification overhead |
| Mostly PLA and PETG parts below 250 mm | Usually overkill | A smaller enclosed or open printer can cover the work with less footprint and machine commitment |
| Multicolor is useful and QIDI Box compatibility matters | Possible fit | QIDI's current listing says the Plus4 is compatible with QIDI Box, but this is not the same architecture as independent nozzles |
| Soluble supports, independent tools, or minimal material switching is the purchase thesis | Wrong architecture | Compare a dual-nozzle or toolchanger platform rather than asking size and chamber heat to solve a tool-separation problem |
QIDI's regional Plus4 product listing still documents the 305 x 305 x 280 mm build size, second-generation 65°C active chamber, full-auto calibration, and QIDI Box compatibility. QIDI's current main-store comparison and Plus 5 upgrade guide now identify Plus4 as discontinued and Plus 5 as its direct successor. Treat a live regional listing as stock evidence for that region, not proof that Plus4 remains the current Plus-series default. Verify seller, region, condition, warranty, return terms, included revision-specific hardware, and support before paying.
Setup-spool shortcut after the Plus4 decision: If the machine wins and the first jobs are cool, indoor prototypes, organizers, fixtures, or fit checks, Matte Black AF PLA+ is a live GoodPrints candidate for a low-complexity setup lane. It is a setup and profile-learning spool, not a reason to buy a 305 mm active-chamber printer.
- Good fit: ordinary PLA-family parts where dimensional checks, surface quality, and repeatable handling matter more than heat, weather, repeated flex, chemical exposure, or abrasive reinforcement.
- Skip this shortcut: the ABS, ASA, nylon, PC, flexible, filled-material, hot-service, outdoor, chemical, or consequence-heavy work that actually justified the Plus4.
- Compatibility boundary: PLA+ and PLA Pro are not standardized classes. This third-party spool is not a QIDI preset, QIDI Box, high-speed, performance, or feed-fit guarantee; qualify the exact spool, feed path, build surface, profile, cooling, and part geometry together.
Shop Matte Black AF PLA+ on GoodPrints
GoodPrints sells this live Shopify Collective product directly. Inventory can change; the product page is the current source for availability.
Plus4 or Plus 5: the current buyer decision
Answer first: choose Plus4 only when its verified all-in price or a specific retained feature beats the lifecycle risk. Choose Plus 5 for an ordinary new Plus-size purchase. QIDI says Plus 5 launched on August 5, 2026, is the current Plus-series model, and succeeds the discontinued Plus4. Remaining regional inventory does not erase that product-cycle change.
| Your actual decision | Cleaner choice | What must be proved |
|---|---|---|
| Buying new with a small price gap | Plus 5 | Compare delivered price, warranty, return terms, current regional support, and the complete QIDI Box configuration rather than a stale list price. |
| Discounted, used, refurbished, or open-box Plus4 | Plus4 can win | Confirm serial and revision, chamber and bed heat, full-plate first layer, motion, camera, filter path, included Box hardware, service history, parts access, and a return or repair allowance. |
| Existing Plus4 that fits every real file | Keep Plus4 | Plus 5 keeps the same published 370°C hotend, 120°C bed, 65°C chamber ceiling, and 600 mm/s maximum. Do not replace a qualified machine merely for the model number. |
| Recurring parts cross 305 mm or 280 mm tall | Plus 5 first | Slice the supported production geometry. Plus 5 is 320 x 320 x 300 mm; the gain is 15 mm on X and Y and 20 mm on Z, not unlimited large-format capacity. |
| Every job fits within 270 x 270 x 256 mm | Compare Q2 | If chamber heat is the real requirement and size is not, the smaller current machine may avoid idle capacity. |
| Real files exceed 320 x 320 x 300 mm | Compare Max4 | QIDI lists 390 x 390 x 340 mm, but confirm footprint, mass, power, failed-job exposure, material use, and whether the part can be split safely. |
Plus 5 changes the workflow more than the material list
QIDI's current official comparison lists Plus4 at 305 x 305 x 280 mm and Plus 5 at 320 x 320 x 300 mm. It also lists a 400 W second-generation Plus4 chamber heater and a 550 W third-generation Plus 5 heater, while both retain the same 65°C chamber ceiling. The larger heater can change warm-up and recovery; it does not raise the published ceiling or certify a finished part for heat.
Plus 5 also changes the ownership package: load-cell leveling in the hotend, a G3 pre-filter plus H12 HEPA plus carbon stack, AI camera functions, and 2.4/5 GHz Wi-Fi. Plus4 keeps a larger 5-inch screen and its built-in tangle sensor, while the official Plus 5 comparison says Plus 5 tangle detection requires QIDI Box. Those are workflow differences, not automatic reasons to discard a proven Plus4.
Material boundary: the official guide says both machines retain a 370°C hotend, 120°C bed, and 65°C chamber ceiling and support the same broad material families. That does not make every PLA, PETG, TPU, ABS, ASA, PA, PC, or fiber-filled grade interchangeable. The exact spool's nozzle material and diameter, drying, bed, chamber, ventilation, filtration, speed, layer-bond, annealing, and post-conditioning requirements still control. A filter reduces some emissions; it does not certify room air or replace appropriate ventilation.
Check QIDI Box hardware as part of the purchase
Do not reduce this decision to a generic "QIDI Box compatible" badge. QIDI's current expansion-kit page says the Plus4 kit is not compatible with Q2 and directs buyers to select the machine-specific kit. QIDI's Plus 5 transition guide says a Box carried from Plus4 or Q2 needs the QIDI Box hub and signal cable for Plus 5, while a Max4-origin Box works directly. Confirm the printer, Box, hub, signal cable, tubing, firmware, cutter or adapter parts, and intended color count as one configuration before pricing the deal.
Use a discount threshold that pays for lifecycle risk
There is no universal safe discount because condition, region, freight, tax, warranty, included Box hardware, spare parts, and seller support vary. Build a delivered-cell comparison instead: printer, required Box parts, enclosure and filtration maintenance, build surfaces, nozzles, material drying, bench and power needs, likely repair allowance, and the cost of one failed large job. The Plus4 discount should be large enough to cover the specific support and condition risk you are accepting, not merely large enough to look cheaper in a product grid.
For an existing Plus4, upgrade only when measured files need the added 15 x 15 x 20 mm envelope, the newer filtration or leveling workflow solves a recurring problem, or the current machine's condition makes replacement sensible. For a new buyer, the burden of proof is reversed: Plus4 must be meaningfully better for the exact deal, because Plus 5 is the current successor.
Safety and use limits
Neither printer specification is a safe-working-load, heat-life, pressure, sealing, chemical-resistance, fatigue, electrical, food-contact, medical, vehicle, protective-equipment, or regulatory certification. Qualify the exact material, orientation, layer bond, moisture state, geometry, hardware, environment, inspection plan, and finished part. Use appropriate supervision, placement, electrical capacity, clearance, ventilation, and current manufacturer instructions. High-consequence parts need an appropriate professional process and documented engineering review.
Current official sources: QIDI's 2026 printer comparison, QIDI's Plus 5 versus Plus4 transition guide, the regional Plus4 product listing, and the model-specific QIDI Box expansion-kit page.
The four-question Plus4 buyer test
1. Do real files exceed the smaller enclosed class?
Start with finished-part bounding boxes, required orientation, brim or support allowance, and the space needed to remove the part safely. Do not buy from the nominal dimension alone. A 280 mm part may fit the 305 mm axis on paper but still become awkward once orientation, adhesion margin, or support geometry enters the job.
The useful comparison is how many recent jobs could not be placed sensibly on a smaller machine. Use the Plus4 build-size guide when dimensions, rather than the whole buyer verdict, are the unresolved question.
2. Does the active chamber solve a recurring material problem?
A 65°C active chamber is meaningful when the queue repeatedly includes materials and geometries that benefit from controlled chamber heat. Larger ABS and ASA housings, long nylon parts, broad flat fixtures, and similar work can make chamber control part of the process argument. A chamber is not a substitute for the exact filament maker's settings, dry material, correct build surface, wear-ready hardware, or a validated profile.
If material compatibility is the real uncertainty, route into what materials the Plus4 can print. For a narrower decision, use the Plus4 ABS and ASA buyer guide or the Plus4 TPU buyer guide. This page should decide whether the machine fits, not duplicate every material workflow.
3. Is QIDI Box compatibility enough, or do you need separate tools?
The current QIDI listing changes an older buyer assumption: the Plus4 is listed as compatible with QIDI Box for multicolor work. That makes it more relevant to buyers who want a larger enclosed QIDI plus managed material switching. It does not turn the printer into a dual-nozzle or toolchanger machine.
If the job depends on separate support-interface material, reduced single-nozzle switching, or independent tool assignment, compare X2D vs QIDI Plus4. If multicolor is a convenience rather than the whole purchase thesis, QIDI Box compatibility can stay a useful secondary benefit.
4. Will the machine have a defined job after the first month?
The strongest Plus4 purchase has an assigned workload: larger enclosed fixtures, recurring housings, heat-managed functional parts, or batch layouts that use the bed. The weakest purchase is a general desire for a bigger, hotter, more serious-looking printer. Define what gets routed to the Plus4 and what stays on the existing machine before ordering.
Run a ten-job bottleneck audit
Review ten representative upcoming jobs and record the finished size, required orientation, material, quantity, chamber need, support strategy, and acceptance check. Then classify each job:
- Needs the Plus4 class: it exceeds the smaller machine in a useful orientation or repeatedly needs active chamber control.
- Benefits but does not need it: the larger bed improves batching or convenience but a smaller enclosed printer still completes the part.
- Does not use the step-up: the job is ordinary PLA or PETG, fits easily on a smaller bed, and gains little from chamber capability.
- Needs a different architecture: the bottleneck is independent tools, soluble-support workflow, office deployment, or something the Plus4's size and chamber do not address.
If only one speculative job lands in the first category, wait. If several recurring jobs do, and their cost is visible in splitting, warping, queue delay, outsourcing, or rejected parts, the machine has a defensible role.
Who should buy the QIDI Plus4?
- Larger functional-part owners: people with recurring one-piece geometry that genuinely uses the 305 x 305 mm bed.
- Material-first small shops: operators who already dry, profile, and qualify ABS, ASA, nylon, or comparable demanding filaments and want a larger active-chamber station.
- QIDI owners outgrowing the compact lane: buyers who know why they like QIDI's enclosed approach and can name what a larger machine fixes.
- Mixed-queue buyers: people who will use the Plus4 for larger enclosed work while treating QIDI Box compatibility as a useful addition, not as proof that every multicolor workflow is ideal.
Who should skip it?
- Buyers whose work fits a smaller enclosed printer: extra capacity is not free if it adds footprint, inventory, and maintenance without changing output.
- PLA-first hobby queues: active chamber capability and larger enclosed volume may sit mostly unused.
- Buyers shopping by future possibility: “I might print a large nylon part someday” is weaker evidence than ten known jobs.
- Independent-tool buyers: a dual-nozzle or toolchanger decision should not be disguised as a Plus4 size decision.
- Teams without process ownership: the machine does not replace material storage, profile control, maintenance, or first-article approval.
Choose the alternative by the failed test
| Why the Plus4 is not the fit | Cleaner next comparison | Decision it answers |
|---|---|---|
| You want a smaller mainstream enclosed default | P2S vs Plus4 | Compact everyday ownership versus larger active-chamber capacity |
| You want another large enclosed platform | Plus4 vs K2 Plus | Two larger enclosed machine paths |
| You value serviceable ownership over maximum bed area | CORE One vs Plus4 | Ownership model versus larger heated-chamber room |
| You need independent tool workflow | X2D vs Plus4 | Dual-nozzle value versus larger single-tool capacity |
| You know the Plus4 is wrong but not why | Best Plus4 alternatives | Route out by size, ecosystem, or tool architecture |
Use a representative proof job
Before standardizing the machine, qualify the exact workflow that justified it. Use the planned filament, geometry, orientation, chamber strategy, build surface, and acceptance limits. Check dimensions, flatness, layer bonding, surface quality, support removal, restart behavior, and repeatability. A small demo model does not prove a 290 mm ASA housing or a long nylon fixture.
For a business queue, document who owns the profile, how filament is dried and stored, what triggers requalification, and which machine takes the work if the Plus4 is unavailable. The full QIDI Plus4 review is the better next page once the broad buyer fit is confirmed.
Prove the setup spool before the demanding queue
- Start with the real setup job: choose geometry that checks first-layer behavior, dimensions, holes, walls, bridges, and surface finish without pretending PLA proves active-chamber materials.
- Use current official guidance: begin with the printer and spool makers' current PLA-family instructions, then record the actual nozzle, plate, feed path, temperature, cooling, and speed used.
- Validate the feed path: test the exact external-spool or managed-feed route planned for use; the spool label alone does not prove QIDI Box or every holder and buffer path.
- Check release and repeatability: inspect plate release, warping, dimensions, layer bonding, surface quality, and a second representative print before calling the profile stable.
- Keep the machine thesis separate: qualify ABS, ASA, nylon, PC, TPU, or filled materials independently when those workflows are why the Plus4 was purchased.
Buy one setup spool, then qualify the real workload: Matte Black AF PLA+ is a focused GoodPrints option when the first Plus4 job is cool, indoor, and genuinely belongs in the PLA family. Choose and validate the required material separately when chamber heat, weather, flex, chemicals, wear, reinforcement, or consequence sets the requirement.
Check current Matte Black AF PLA+ availability
Start with one spool and approve a representative setup part before a long print or repeat batch.
Buyer verdict
Buy the QIDI Plus4 when several real jobs use its 305 x 305 x 280 mm build space, active chamber control matters to the material plan, and the machine will have a defined larger enclosed workload. Treat current QIDI Box compatibility as an added multicolor route, not as a substitute for a dual-nozzle or toolchanger architecture.
Skip or delay it when the queue fits a smaller printer, mostly uses easy materials, or depends on future possibilities. If finished parts matter more than printer ownership, use the buy-versus-service checkpoint before adding another machine; if material, process ownership, or repeatability is still open, review JC Print Farm first. If the file, quantity, material, finish, and delivery target are already defined, work through the quote-prep checklist before the tracked quote intake.
Common questions
What is the QIDI Plus4 build volume?
QIDI currently lists 305 x 305 x 280 mm. Confirm the real part orientation, adhesion margin, and support allowance rather than assuming every model below those nominal dimensions fits equally well.
Does the QIDI Plus4 have an active heated chamber?
Yes. QIDI's current product listing states second-generation active chamber heating up to 65°C. Whether that matters depends on the exact filament, geometry, and process guidance.
Does the QIDI Plus4 work with QIDI Box?
QIDI's current listing says the Plus4 is compatible with QIDI Box for multicolor work. That does not make it an independent dual-nozzle or toolchanger printer.
Is the Plus4 worth buying for PLA and PETG?
It can print an ordinary-material queue, but PLA or PETG alone rarely proves the need for a 305 mm active-chamber machine. Buy it when size, material range, or a mixed workload uses the step-up.
Should a small shop buy the Plus4?
Yes when it can assign recurring larger enclosed jobs, document profiles and material handling, and name the acceptance checks. No when it would be a general spare machine without a defined queue.
Availability note (checked July 27, 2026): PrintDry Pro 3 currently has no active Amazon offer. The compact recommendation points to the buyable EIBOS Polyphemus for larger and engineering-material spool recovery; it is not the unavailable PrintDry model.