QIDI Plus4 — Research File (observed 2026-09-20)

Published · Researched 2026-09-20

Overview

The QIDI Plus4 is a fully enclosed CoreXY FDM 3D printer from QIDI Tech (Shenzhen), positioned as a prosumer/engineering-materials machine. It launched in 2024 as QIDI's flagship heated-chamber consumer printer: 370°C hotend, 120°C bed, 65°C actively heated chamber, 305×305×280 mm build volume, Klipper-based open firmware.

Current 2026 status: DISCONTINUED as a current model. QIDI's own product page (qidi3d.com/products/plus4-3d-printer, page crawled 2026-09-18) states: "This model has been discontinued. The QIDI Plus4 is no longer in production. Its direct successor is the QIDI Plus5." The successor QIDI Plus5 launched globally on 2026-08-06 at $749 ($899 Combo): 320×320×300 mm build volume (18% more), same cabinet footprint, 3rd-generation 65°C chamber heating at 550W (37.5% more power than Plus4), X-axis linear rails, nozzle-contact bed leveling sensor, AI camera, and a nozzle filament cutter (press release via Minnesota Headlines/Hope Tribune, 2026-08-06; 3dprinting.com launch coverage, last updated ~20 days before 2026-09-20).

Timing: a QIDI 3D-printer comparison article updated ~2026-07-28 still listed the Plus4 at $699 as part of the current lineup (Q2C $379 / Q2 $499 / Plus4 $699 / Max4 $1049), so the discontinuation landed roughly between late July and mid-September 2026, aligned with the Plus5 launch. The Plus4 remains purchasable from third-party retailers (Fabreeko, Amazon listings) while stock lasts, but the Plus4 and Plus4 Combo variants are sold out / no longer buyable on qidi3d.com itself.

Hardware revision history (important for buyers): early 120V-region units had a chamber-heater SSR (solid state relay) control board that melted; QIDI responded by (a) capping chamber-heater duty cycle in firmware and (b) designing a revised SSR board. Fabreeko's current Plus4 listing describes stock as "the latest edition with newer chamber heater controller and other quality of life improvements." However, 3DWithUs warns "it is unclear which machines have been updated and which still contain the old board" for older retail stock (3dwithus.com review, crawled 2026-09-20).

Key specs table

All figures from QIDI's published specs (qidi3d.com technical-specification page and product page, observed 2026-09-20) unless noted.

Pricing

All prices observed / dated 2026-09-20. MSRP: $799, current official price $699 (qidi3d.com product page, crawled 2026-09-18 — but the printer is discontinued and both Plus4 and Plus4 Combo variants show "Sold Out" on the official store, so it is effectively not purchasable direct from QIDI).

Successor reference: QIDI Plus5 MSRP $749 ($899 Combo), launched 2026-08-06.

What's included / what's needed

In the box (per 3DWithUs review unboxing, "What's in the Box" section, crawled 2026-09-20): the Plus4 printer itself, touch screen (separate install), door handle, filament holder with mount block, spare fuse, Allen keys, 7 mm wrench, flathead screwdriver, scraper, glue stick, USB drive, spare parts kit, Ethernet cable, power cable, user manual, lubricant, thermal paste, chamber-filter bag (inside the in-chamber filter box at the rear — reviewer notes to remove it from its plastic bag during setup). Two plastic shipping brackets + 4 bed screws must be removed before first use; setup takes ~10 minutes.

What's needed (not included):

• Filament — none listed in the box; buyer supplies 1.75 mm filament (any brand; QIDI publishes tuned profiles, e.g. ABS-GF, QIDI PAHT-CF). For PLA, QIDI/community guidance: print with the glass lid removed or vented to avoid chamber overheating/clogs.
• A computer or phone for QIDI Studio / Orca Slicer / the QIDI mobile app (printer also works via USB stick / LAN).
• Optional: QIDI Box multi-color unit (sold separately) for multi-filament printing; extra nozzles (0.2/0.6/0.8 mm) are optional accessories, not in the box.

Support reality

• Warranty terms (official store, observed 2026-09-20): 1-year coverage, 14-day no-reason return, 30-day price match, "lifetime tech guidance." These are store-policy headers on the Plus4 page; no separate Plus4-specific warranty document was located — treat as brand policy rather than model-specific fine print (UNVERIFIED whether labor-only vs parts-included).
• Known-issue response (verified, not rumor): QIDI's chamber-heater SSR fix is real and documented three ways: (1) the community Plus4-Wiki (updated 2026-09-14) documents the melting SSR board on early 120V units, QIDI's firmware duty-cycle cap, and the later revised SSR board; (2) an Amazon review from 2026-08-21 reports QIDI sent a replacement SSR upgrade kit "quickly with coherent and easy to follow instructions"; (3) 3DWithUs notes QIDI sent replacement boards to affected users. A 2024-era Reddit thread (r/QidiTech3D) shows QIDI support responding to a hot-chamber auto-leveling complaint by shipping a replacement leveling sensor, build plate, and nozzle, plus advising against preheating the chamber before leveling. Pattern: support is responsive with free replacement parts, but some fixes are workarounds pending firmware updates.
• Parts/service availability: qidi3d.com maintains a "For Plus4" spare-parts/accessories section (hotends, plates, nozzles, belts, etc.) — still listed on the 2026 storefront. Third-party replacement parts remain "readily available and competitively priced" per a 3dprint.com review (~2024-11; aging data, but consistent with continued 2026 retail listings). Community Plus4-Wiki is actively maintained (updated 6 days before 2026-09-20) with firmware tuning guides, SSR upgrade docs, and Orca profiles; QIDI also runs an official Discord.
• Reputation in 2026: broadly pragmatic-positive among owners — QIDI ships fixes and replacement hardware without much friction — tempered by the discontinuation: buying a Plus4 now means a discontinued platform with the Plus5 (and its $749 price, close to current Plus4 street prices) as the supported successor. Firmware continues via Klipper v0.12 base with community tweaks; note that official QIDI firmware 1.7.0 introduced breaking changes for Cartographer-probe users (per Plus4-Wiki, 2026).

Community verdict

Owners and reviewers consistently rate the Plus4 as a strong engineering-materials printer at a midrange price — 3DPut's 2026 verdict calls it "a specialized tool that delivers," a 2026 YouTube technical review calls it "an incredibly capable tool that handles demanding prints with ease," and a six-month owner on Amazon (review dated 2026-08-21) calls it "by far the most reliable printer I have owned" after ~20–30 rolls of filament. The counterweights are real and well-documented: the early SSR board failures (fixed in later units, but mixed stock persists), genuinely slow chamber heat-up after the firmware duty-cycle cap, loud operation, and the hot-chamber auto-leveling quirk — and as of ~August 2026 the verdict conversation has shifted to "buy the Plus5 instead," with owner-group chatter in September 2026 comparing the Plus5 against the Max4 and rivals like the Sovol SV08.

Images

• the bundled image library/qidi-plus4-01.jpg — primary/exact-model: official QIDI marketing shot, Plus4 with touchscreen and QIDI Box multi-color unit, "QIDI Plus4 / Every Detail Perfectly Printed" banner. (Source: qidi3d.com CDN, verified HTTP 200, converted PNG→JPEG.)
• the bundled image library/qidi-plus4-02.jpg — exact-model: clean front render of the Plus4 with "PLUS4 / QIDI" toolhead branding and 305×305×280 mm on the bed. (Source: qidi3d.com CDN, verified HTTP 200.)
• the bundled image library/qidi-plus4-03.jpg — exact-model: real review photo of the Plus4 printing a warrior bust, "QIDI PLUS4" visible. (Source: 3DWithUs review, verified HTTP 200.)
• Substitution note: the first candidate for image 03 (official performance_pattern.png) downloaded fine but turned out to be a decorative line-art graphic with no printer in it, so it was discarded and replaced with the 3DWithUs review photo; the swap is recorded here. No other images failed.
• Image-search caveat: one image-search result pointed at an X-Plus 4 (older, different model) photo; it was rejected as not the Plus4.

Deepening pass (2026-09-20)

Social-source attempts this pass

• Facebook CLI group-post searches ("Plus4" in 3D Printing / 3D Printing World): 0 results; CLI limitation, not evidence of absence.
• Plus4-Wiki on GitHub (community, updated Sep 2026): very active — SSR upgrade docs, probing/Z-offset guides, firmware notes. Strongest signal source this pass.

Price re-verification (2026-09-20)

• Official store: Plus4 and Plus4 Combo Sold Out / discontinued — no change. Fabreeko $649 (latest chamber-heater-controller edition) still the live US street option. Amazon US $699 — live price still not directly fetched (UNVERIFIED); stale data risk.

New evidence: firmware update broke Z-offset (owner review, Aug 2026)

• Retailer product review (shopabunda, Aug 11, 2026, Rich Weinberg): unit arrived with a broken filament cutter bar; then a firmware update turned a working machine into nozzle-rubbing after auto-level — owner had to set Z offset to +0.1 mm, and the printer re-runs auto bed-level before every print even with the option off, re-zeroing the plate and scraping prints. "A company who puts out firmware that just does not work right." Single-owner account, but the complaint pattern (firmware-era Z regression) is corroborated below. https://www.shopabunda.com/products/qidi-plus4-3d-printer-max-600mm-s-high-speed-printing-65-chamber-heat-fully-auto-leveling-370-c-direct-extruder-with-integrated-nozzle-support-pps-cf-filaments-large-print-size-12-x12-x11

New evidence: stock Z-offset "not entirely reliable" (Plus4-Wiki, Sep 2026)

• Community Plus4-Wiki (crawled Sep 2026): "stock Plus4 implementation is not entirely reliable. Multiple owners have reported unreliable first layers, or even gouged print plates despite ABL sensors." The reliability chain: nozzle torque at 300 °C, clean/lubed Z lead screws, scrubbing-brush + PEI cleaning plate condition, nozzle cleanliness — failure at any link degrades the nozzle-touch Z end stop. Aftermarket nozzles/hotends "poorly sized, ill-fitting" per the wiki. Firmware 1.7.0 introduced breaking changes for Cartographer-probe users; Cartographer firmware 5.1 has reported issues on Plus4 (5.0 recommended). https://github.com/qidi-community/plus4-wiki/blob/HEAD/content/Kuo-Steps-for-Improving-Z-Offset-Reliability/README.md ; https://github.com/qidi-community/plus4-wiki/blob/HEAD/content/bed-scanning-probes/cartographer3d/README.md

New evidence: 2026 review still flags the SSR on early units

• 3DPut review (crawled Sep 2026): loves — engineering material versatility, active chamber, industrial construction, open Klipper, high-flow hotend. Dislikes — "SSR concern on early units (verify upgraded relay if used)", bulk/weight, UI polish, plate changes may require re-meshing, thinner service network. Comparison table: vs Bambu P1S ($799), K1 Max ($799), Prusa Core One ($1,399) — Plus4 differentiator remains high-temp capability at midrange price. https://3dput.com/qidi-plus4-review-the-heated-chamber-powerhouse-for-engineering-filaments/

New evidence: 100+ hour prints are real — with maintenance

• 3dbgprint dealer review (crawled Sep 2026): Reddit/community owners share ASA-CF, PPS-CF, 100+ hour prints "without serious problems, provided good maintenance and calibration"; X-axis maintenance and guide lubrication are recurring forum topics — treat lubrication as a scheduled obligation, not optional. https://3dbgprint.com/en/produkt/qidi-plus4-corexy-3d-printer/

Open questions carried forward

• Which retail batches still carry the old SSR board.
• Discontinuation timing window (~2026-07-28 to 2026-09-18).
• QIDI warranty-honoring on a discontinued model in 2027+.
• Live Amazon US price on 2026-09-20.

UNVERIFIED / open items

• Live Amazon US price on 2026-09-20 (price-index data was stale; not directly fetched today).
• Whether discontinued-model warranty claims will continue to be honored by QIDI in 2027+; exact warranty fine print (parts vs labor).
• Exact discontinuation date (window: between ~2026-07-28 and ~2026-09-18 based on QIDI's own pages).
• Official dB noise spec (does not exist; only third-party measurements/qualitative notes).
• Which specific retail batches still contain the old SSR board (3DWithUs flags this as unclear).
• Instagram: site-scoped search returned mostly YouTube/TikTok cross-posts; no direct standalone Instagram post URLs were captured. Community presence is much stronger on Facebook (owners groups), Reddit r/QidiTech3D, Discord, and YouTube.

Deepening pass 3 (2026-09-21)

facebook-cli status: groups posts --group-id ... --query "..." re-tested 2026-09-21 — still returns [] (endpoint remains broken). No new group pass run; Plus4 coverage remains as captured in the pass-2 ledger (owner groups, Amazon owners, Plus4-Wiki, Reddit r/QidiTech3D, Discord).

Findings

• No new failure modes or owner-fix reports surfaced in this pass. The discontinuation (confirmed on QIDI's site, Sep 2026) and SSR-board saga remain the defining Plus4 story; the machine is effectively a clearance/used-market buy now.
• No fresh used-market prices captured this pass — live reseller-price gap from the pass-2 UNVERIFIED list persists. A reasonable working assumption (UNVERIFIED): used Plus4s should trade well below the $649–$699 MSRP given the discontinuation and the Plus5's aggressive $749 spec sheet, but no listings were captured to confirm.
• Plus5 context (see qidi-plus5 pass-3): Tom's Hardware's Aug 2026 Plus5 review ("toe-to-toe with Bambu's H2 series for nearly half the price") makes the Plus4's used value proposition harder — buyers should treat the Plus4 as a buy-it-cheap engineering workhorse, not a hold-value asset.

Sources added

• None new beyond the Plus5 cross-reference (qidi-plus5.md pass-3 section).

Sources

• qidi3d.com — retrieval date not recorded
• fabreeko.com — retrieval date not recorded
• shopabunda.com — retrieval date not recorded
• github.com — retrieval date not recorded
• github.com — retrieval date not recorded
• 3dput.com — retrieval date not recorded
• 3dbgprint.com — retrieval date not recorded