Cyclone Pre-Separator

Identity

• Scope. This entry is about auxiliary cyclone pre-separators: passive, Dust Deputy-class accessories installed between a dust-producing tool and a compatible powered vacuum or dust collector. A Thien-baffle (lid-style) separator is a related subtype with its own anatomy (below). Complete motorized cyclone dust collectors are a different system and belong to the Dust Collector entry. Industrial cyclones are lineage and context only.
• Names: cyclone pre-separator; auxiliary cyclone; two-stage cyclone; Dust Deputy® (a marked Oneida Air Systems product family; no evidence was produced here that it became a generic term); Thien baffle (a lid-style subtype, documented publicly by Phil Thien); cyclone lid.
• Family/category: an add-on separation stage — not a standalone dust collector or vacuum — that sits inline between a tool's dust port and a compatible shop vacuum or dust collector, using centrifugal and inertial forces to move a portion of the larger or denser particles toward the wall and into a collection receptacle while the remaining airstream continues to the downstream machine and filter.
• One-line: a passive separator installed upstream of a compatible vacuum or collector that drops a portion of the chips and dust into a sealed bin before the air reaches the host machine's filter, which can slow filter loading and help preserve airflow. It is one stage in a system and not itself a filter, a source-capture hood or a barrier to prohibited materials.
• Explicitly NOT: a Dust Collector or Shop Vacuum on its own — the unit itself has no motor or impeller and provides no suction; the collection system it sits in needs a fan or vacuum source and may have electrical, mechanical and explosion-protection components. Also not an Ambient Air Cleaner — a cyclone separates heavy particulate from a moving airstream at the source; an ambient air cleaner recirculates and filters the whole room's air after fine dust is already airborne. Confusing "this tool removes dust from my shop air" with "this tool separates chips from my dust-collection airstream" is this entry's central Beginner-trap finding (below).

✦ How NOT to use it

• Not-for: stand-alone dust collection or air filtration; prohibited, hot or unassessed material; grain, cement, mining or other industrial combustible-dust service.
• Dangerous — read the manuals first. Put the exact separator manual and host-machine manual first: identify the collected material, and never use a hobby unit for a prohibited or unassessed dust, liquid or gas.
  • Prohibited materials (Oneida manual page, read in this pass [DUST-ONEIDA]): do not vacuum flammable or combustible liquids or gases such as gasoline, lighter fluid or natural gas, and do not use the cyclone near them; do not vacuum anything burning or smoking (cigarettes, matches, hot ashes); explosive dusts named include coal, magnesium, grain, aluminum, sugar, flour and gunpowder; the page also says "Wood dust mixtures are highly flammable and can be explosive," not to introduce sparks or ignition sources, and not to vacuum toxic materials without a HEPA filter. Also do not collect hot, burning, sparking, flammable, explosive, toxic or otherwise prohibited material.
  • Foreign objects and ignition (corrected). The earlier claim that a screw or nail "hits the impeller and puts a spark in the cyclone's bin" is withdrawn. A separator sits upstream of the host machine; material it drops falls into its own bin and does not reach the impeller, while material that bypasses it can reach downstream equipment, where an impact is a downstream event. Foreign objects can damage downstream equipment or create ignition hazards if they pass the separator. Diagram the actual tool, separator and bin, host machine and filter path for the specific configuration. Pentz's impeller-spark warning concerns a dust collector used as a vacuum and is not a universal path for every auxiliary layout.
  • Static discharge is a real ignition source (restored). OSHA's Woodworking eTool lists static electrical discharge among ignition sources and recommends grounding equipment prone to static charge [DUST-OSHA] (read in this pass). Oneida's manual recommends grounding for fine dust (conductive tape at the openings on a steel cyclone and connections) and says to follow all local, state, federal and NFPA codes, with licensed-electrician wiring and insurance requirements checked [DUST-ONEIDA]. Oneida's product page says its anti-static components "significantly reduce the likelihood of static shocks," a reduction and not elimination [DUST-ONEIDA2]. Static behavior and required bonding depend on the equipment, materials, ducting, scale and applicable code; do not infer safety from hobby anecdotes such as one person's PVC ducting without incident.
  • Housekeeping. Never blow accumulated dust down with compressed air; OSHA says it produces the dust cloud with the greatest explosion hazard [DUST-OSHA]. Emptying a bin is an exposure task: shut down and isolate the system, avoid raising dust, use the manufacturer's emptying method, and clean up with an approved vacuum or other method that does not disperse dust. Combustible-dust installations beyond a hobby accessory need professional design and applicable fire and explosion controls.
  • Material gate. Wood, treated wood, old paint, drywall, silica-bearing material, metal, composites and finishing residues present different toxic, reactive, abrasive and combustible hazards [manual, relayed].
• Commissioning checklist (pressure loss, airtightness, collapse, stability). Based on Oneida's product page and manual page read in this pass, plus the review:
  • Use the specified pressure-rated or reinforced receptacle and lid. The product page says the bucket should not be old, damaged or thin-walled, recommends 90 mil wall thickness or higher, and says stacking two thin-walled buckets can help [DUST-ONEIDA2]. A blocked hose can put a pail and lid under substantial negative pressure and collapse an unsuitable receptacle [manual, relayed].
  • Secure and stabilize the assembly; tall bucket-and-cyclone stacks can tip and hoses can detach [manual, relayed] (neither Oneida page read addresses tipping).
  • Use the correct inlet and outlet orientation and supported hoses; match the 2.5-inch connection to the 2.5-inch vacuum hose as the product page specifies [DUST-ONEIDA2].
  • Seal every joint; air inleakage degrades collection efficiency and inlet velocity [DUST-EPA].
  • Expect lower initial airflow with the separator and fittings added; test actual capture and airflow at the tool.
  • Keep at least one open air path as the host system requires [manual, relayed].
  • Inspect for leaks and collapse, and empty the bin at the manufacturer's interval before material re-entrains.
• Damaging:
  • Mismatch with the host system. A shop-vacuum cyclone is a high-pressure, low-airflow product and a dust-collector cyclone a low-pressure, high-airflow one. Oneida's manual page says the small Dust Deputy is not suitable upstream of a 650 CFM single-stage collector [DUST-ONEIDA]. A mismatched or leaking system can pass material it should have separated.
  • Letting the collection bin overfill. A full bin can lose separating volume and allow separated material to re-entrain into the outlet airstream.
• Beginner-trap:
  • Mistaking separation for filtration. A pre-separator drops a portion of the chips and dust; it is not a barrier filter, and "does not filter" must not be read as "does not remove particulate." Visible chip capture is not proof of adequate fine-dust exposure control; the fine dust that continues on is handled by the downstream filter and source capture.
  • Trusting the word "cyclone" alone as a performance guarantee. Efficiency is a curve set by particle size and density, geometry, inlet velocity, pressure drop, loading and leakage [DUST-EPA]; a manufacturer's "up to 99.9%" is tied on Oneida's own spec table to fine wood dust ("Removes over 99% of fine wood dusts") and does not disclose test detail [DUST-ONEIDA2].
• Lineage-misuse:
  • Comparing unlike products by name. Pentz's self-published targets for a larger source-capture system, Oneida's small vacuum-class unit and a bucket-lid baffle are different products with different matching rules; none stands in for another. This is the lineage-misuse class: treating variants as interchangeable.
  • Neglecting the downstream filter on the belief that the separator is "catching everything".

Correct use

• What it's genuinely good at: when matched to the host machine, reducing the dust load that reaches a vacuum's or collector's filter, which can slow filter loading, reduce cleaning frequency and help preserve airflow, and keeping the receptacle handling to a sealed bin.
• How to use it well (short version — the workbench holds deep operation): follow the exact manuals for the separator and the host machine first. Match the separator to the host machine's pressure/airflow class, port and hose/duct size, the tool's capture requirement, the collected material and the manufacturer's performance data. Do not use a figure like "1,000 CFM through 7-inch ducting" as a pass/fail threshold; that is Bill Pentz's self-published design target for source capture and transport on larger shop machines, a different question from separator efficiency. Empty the bin before the manufacturer's fill limit; Oneida's manual page says to empty the drum after each use.

✦ Matching

• Does: moves a portion of the chips and dust out of a moving airstream into a bin upstream of a compatible vacuum or collector; can slow filter loading and help sustain airflow compared with the same machine without one. Cyclone efficiency is particle- and design-dependent: many units are used as pre-cleaners for larger particles, higher-efficiency designs can collect some smaller particles at greater pressure drop and energy cost, and the downstream filter and verified source capture remain essential [DUST-EPA].
• Best fit: an auxiliary separator explicitly sized and approved for the existing wet/dry vacuum or dust collector, where reducing filter loading and bin handling is the goal.
• Conditional: planers, jointers, table saws, sanders, drywall, concrete, liquids and abrasive material. Suitability depends on host airflow and static-pressure class, source hood, ports and ducting, material hazards, separator model, receptacle and filter.
• Poor fit: any prohibited dust or liquid; hot, smoldering or sparking material; explosive atmospheres; a host with incompatible pressure or airflow; a non-rated collection drum; or any use that treats the separator as a substitute for source capture and final filtration.
• Kit-fit — pairs with: a Shop Vacuum (small Dust Deputy-class line) within the manufacturer's stated matching; for dust collectors, the manufacturer's model for that collector class; rigid or reinforced hose supported and sealed; a downstream filter rated for the material.
• Kit-fit — substitutes for: nothing on its own. It does not substitute for an Ambient Air Cleaner, source-capture design or a proper final filter. A pre-separator does not establish adequate source capture or breathing-zone exposure control; NIOSH woodworking guidance emphasizes local exhaust design at the generating machine [manual, relayed].
• Thien-baffle subtype, separate block: a bucket-lid baffle separator is matched to a wet/dry vacuum and its own lid and bucket; it is described by its maker as a separation and filter-life improvement, not a health-protection device; use the subtype's own design documentation and the same prohibited-material and commissioning gates below.
• Not-for (project-keyed): a shop with no compatible host machine; any prohibited or unassessed dust, liquid or gas; any host whose airflow class does not match the model; relying on it as a stand-alone air-quality solution.
• Suggested match fields: separator_type, host_system_class, port_size, rated_airflow_or_matching_rule, pressure_drop, fractional_efficiency_basis, approved_materials, prohibited_materials, receptacle_rating, grounding_requirements, filter_requirement, industrial_code_gate (the reviewer's suggestion).
• Access — not "straightforward". The unit is passive, but setup is not consequence-free: adding a separator and fittings reduces initial airflow, air leaks degrade separation, and the receptacle, hoses and stability need the commissioning checks below. Beginner mistakes are likely at sizing, sealing and material choice.
• Revival: a maker reaches for this when a compatible vacuum or collector is loading its filter too fast; the Fine Woodworking tests above showed a benefit in the tested systems.

Anatomy

• Tangential inlet — the airstream enters the separating chamber off-center, imparting the rotating motion (Finch's 1885 patent describes a tangentially fed case).
• Conical/cylindrical separating chamber — centrifugal and inertial forces move larger or denser particles toward the wall, where they descend while the gas reverses into the central outlet. Efficiency depends on particle size distribution, particle density, cyclone dimensions, inlet velocity, pressure drop, loading and air leakage (EPA cyclone page, read in this pass [DUST-EPA]).
• Vortex finder / outlet tube — the inner tube through which the now-lighter, fine-dust-carrying air exits upward to the downstream vacuum or dust collector's filter/impeller.
• Collection bin/bucket — where separated heavy debris drops by gravity; on a DIY unit, typically an ordinary 5-gallon bucket; on commercial units, a dedicated molded or steel drum.
• Thien-baffle subtype (separate anatomy). A lid-style separator that uses a baffle arrangement inside a bucket lid, not the conical cyclone body above, aimed at stopping separated dust from scrubbing back up into the outlet (Thien's own description). Its cone, vortex-finder and efficiency data do not apply to it.
• Bucket lid / mounting collar — the interface that seats the separator body onto its collection bin; Oneida's own current patent (US 11,419,467) covers a specific version of this part.

Variations (living)

• DIY Thien-baffle bucket lid — Phil Thien's freely published design; a molded or fabricated lid with an internal baffle plate, mounted on an ordinary 5-gallon bucket, inline before a shop vacuum. The lowest-cost, smallest-footprint variant.
• Commercial small-format auxiliary cyclone (Oneida Dust Deputy line, Rockler Dust Right Vortex) — a molded-plastic, purpose-built bucket-mounted separator, typically paired with a Shop Vacuum for single-tool or occasional-use pickup. The Oneida manual page read in this pass describes the Dust Deputy as designed for wet/dry vacuums with ports 2.5" or smaller, and says it is not suitable upstream of a 650 CFM single-stage dust collector (a high-airflow, low-pressure system), recommending Super Dust Deputy cyclones instead [DUST-ONEIDA].
• Out of scope for this entry. Complete motorized cyclone dust collectors (ClearVue, Oneida's larger units, JET, Grizzly) are covered by Dust Collector. Industrial-scale cyclone separators are lineage and context only.

Trades

• General woodworking shop infrastructure — the primary use case: a retrofit accessory for an existing compatible Shop Vacuum or, per the manufacturer's matching, a Dust Collector, subject to the prohibited-material and commissioning gates above.
• Not valid applications for a Dust Deputy-class unit: agricultural/grain handling, cement manufacturing, and mining or mineral processing. Those are engineered industrial systems under different requirements; they appear in this entry as lineage and context only.

Lineage

• Ancestors (patents as dated evidence of particular designs, not a founding genealogy). US Patent 325,521 ("Dust-Collector," John M. Finch, Jackson, Michigan, granted September 1, 1885, assignor to the Knickerbocker Company) is an 1885 documented centrifugal dust-separator patent describing a horizontal cylindrical case with rapid rotation of the air current and a peripheral slot into a settling chamber. Its own specification says rotary separation had already been attempted ("Heretofore it has been attempted to separate the dust from the air by compelling the dust-laden air to assume a rotatory motion," by revolving fan-blades or the air's momentum), read in this pass [DUST-US325]. A patent documents the claimed embodiment; it is not proof that Finch originated the cyclone principle. US Patent 450,372 (Orville M. Morse, assigned to the Knickerbocker Company; filed 1887, granted 1891) is a later documented conical, tangential-inlet design addressing dust re-entry at the apex (not re-fetched in this pass; carried from the original run and the review; the machine-readable text carries an OCR "1836" error for the referenced 1886 application, so quote the scanned patent). US Patent 801,806 (Philip C. Miller, Chicago, 1905) improves tangential-inlet airflow (original run; not re-fetched). Other Knickerbocker-assigned patents (US373,374, US403,362, US403,363, US404,217, US408,987) appeared in Google Patents' "Similar Documents" list; algorithmic similarity does not show assignment, coordination or influence, and they were not opened, so they are leads only.
• Migration from industrial milling to the small woodshop. Cyclone separation existed as industrial process engineering well before Oneida Air Systems (founded 1993 by Robert Witter and Peter Fedrigon; Woodworker's Journal, "Oneida Air Systems Marks 30 Years," 2023-06-16) began offering woodworking-scale products; per that trade retrospective, Oneida's first offering was a cyclone separator. This is reporting about Oneida, not a first-in-industry claim.
• Later products: molded-plastic consumer lines such as Oneida's "Super Dust Deputy" and "Dust Deputy 2.5," documented in the 2023 retrospective as iterating from a 2006 design through 2008 and 2022 versions (trade reporting). US 11,419,467 ("Bucket lid for auxiliary cyclone dust collector," priority 2020, filed 2021, granted 2022, assignee Oneida) claims an improved bucket lid for an auxiliary cyclone system, including stiffening and anti-swirl features; it is not a patent on cyclone separation generally.
• Contemporaries: Dust Collector (the single-stage machine this tool retrofits/upgrades — see below); Shop Vacuum (the other common host machine, especially for the smaller Dust Deputy line); Ambient Air Cleaner (a mechanically unrelated contemporary — filtration of already-airborne room dust, not source-stream separation; per this corpus's own Ambient Air Cleaner entry, "Oneida... does not appear to make a dedicated ceiling-hung ambient air cleaner — their catalog is source-capture only (cyclones, benchtop dust collectors)," a direct confirmation the two product categories are kept distinct even by the same manufacturer); industrial cyclone separators used in other trades are engineered systems under different requirements and are not valid applications for a Dust Deputy-class unit (context only; trade sourcing, not fetched).

History (Petroski "form follows failure" lens)

• What an upstream auxiliary separator changes, in an architecture where the blower is downstream. In a single-stage collector all debris passes the impeller before filtration, which exposes the blades to chips and hands the filter the full load. Oneida's company history (original run; not re-fetched) says standard bag filtration has too high an air-to-cloth ratio. An auxiliary separator installed upstream of the suction machine can drop part of the debris before it reaches the impeller or filter. That statement is restricted to that architecture; collectors with the fan before or after separation, and complete or industrial cyclone systems, must be assessed for their own flow path.
• Dated trade testing, bounded to what it reports. Fine Woodworking, "A Revolution in Dust Collection" (Asa Christiana, Issue #223, 2011-10-27), per the reviewer's reading: pitot-tube and manometer testing showed up to 40 percent airflow loss in the tested non-cyclone machines as filters loaded, 99 percent captured in its Super Dust Deputy test, and a small initial airflow penalty from adding a separator [manual, relayed]. Results are bounded to the tested configurations. The article does not state a causal link between cyclone adoption and wood dust's 2002 carcinogen listing, and no such link is claimed here; the listing and any adoption link would need separate sources.
• An unresolved account, attributed narrowly. The sibling Dust Collector entry credits ClearVue Cyclones' 2004 founding to brothers Ed and Matt Morgano (a company social-media post). Bill Pentz gives a different, self-published account on his own site (billpentz.com), saying he turned his business over to a friend for a royalty and that the friend created Clear Vue Cyclones. These are conflicting, interested narratives; neither was independently corroborated here, and this is an unresolved lead rather than established corporate history.

Human side

• Bill Pentz — a self-published account. On billpentz.com Pentz describes a UC Davis engineering background, 30+ years teaching college engineering, and a wood dust exposure that led to severe pneumonia and retirement from teaching in 2000; he built his own cyclone design ("independent medical school tested to separate airborne dust over six times better than its closest competitor," his own claim, not verified). His research is freely published, not peer-reviewed, and his credentials are disputed in at least one forum thread (LumberJocks). It is treated in this corpus as influential self-published design argument, not as an institutional or peer-reviewed source, and his figures are not safety or performance thresholds for the whole family.
• Phil Thien — publicly documented this baffle configuration. Thien's own page (jpthien.com/cy.htm) describes his baffle and its anti-scrubbing and re-entrainment purpose; it is self-published design evidence, not independent proof of invention priority or universal performance. Per a 2010 Sawmill Creek thread and a 2013 Core77 piece (original run, not re-fetched), he developed the baffle over many prototypes, applied for a patent, and chose to publish it freely. In his forum words the choice between a full cyclone and a bucket-lid baffle comes down to "(1) Cost, (2) Size, and (3) Noise," and he frames the baffle as a separation-efficiency and filter-life improvement, not a health-protection upgrade.
• Robert Witter and Peter Fedrigon — a named commercial founding. Oneida Air Systems, founded 1993 per the Woodworker's Journal retrospective (trade reporting); Witter is a named inventor on US 11,419,467.
• Industrial cyclones, context only. Cyclone separators are used in grain, cement and mining trades as engineered industrial systems with combustible-dust controls. They are not valid applications for a Dust Deputy-class unit.

Proof of existence

• 1885 documented centrifugal dust-separator patent. US Patent 325,521 (John M. Finch, assignor to the Knickerbocker Company; granted September 1, 1885), read in this pass; it acknowledges earlier rotary dust-separation attempts. Google Patents
• A later documented conical, tangential-inlet design. US Patent 450,372 (Orville M. Morse, Knickerbocker Company; filed 1887, granted 1891), per the review and the original run. Google Patents
• A 1905 refinement. US Patent 801,806 (Philip C. Miller, Chicago). Google Patents Original run; not re-fetched.
• Later patents citing the Finch record (as listed by Google Patents in the original run: US 2,803,044, 1957; US 4,028,076, 1977; US 5,800,578, 1998; US 9,211,547, 2015). Citations may be applicant-, examiner- or third-party-added and show relevance, not descent or influence; they are not evidence of a lineage and were not opened.
• A current commercial patent. US 11,419,467 (bucket lid for an auxiliary cyclone system; Oneida), not a patent on cyclone separation generally. Oneida Air Systems patent index
• Thien baffle. No patent grant was confirmed; sources say he applied and chose to publish freely. Treat it as a freely published design.
• Trade testing. Fine Woodworking, "A Revolution in Dust Collection" (Asa Christiana, Issue #223, 2011-10-27), bounded as in History. Fine Woodworking
• Oneida's founding is trade reporting (Woodworker's Journal, 2023-06-16). Woodworker's Journal
• Museum record, search note only. One search did not locate a museum or industrial-heritage collection record for a cyclone dust separator; failure to locate a record in one search is not evidence that none exists.

References

• {title: "US Patent 325,521 — Dust-Collector", author: "John M. Finch, assignor to the Knickerbocker Company", site: "Google Patents", url: "patents.google.com/patent/US325521A/en", kind: patent, note: "directly fetched and read in full text this run"}
• {title: "US Patent 450,372 — Dust-Collector", author: "Orville M. Morse, assignor to the Knickerbocker Company", site: "Google Patents / DATAMP", url: "patents.google.com/patent/US450372A/en", kind: patent, note: "directly fetched and read in full text this run"}
• {title: "US Patent 801,806 — Dust-Collector", author: "Philip C. Miller", site: "Google Patents", url: "patents.google.com/patent/US801806A/en", kind: patent, note: "directly fetched and read in full text this run"}
• {title: "US Patent 11,419,467 — Bucket lid for auxiliary cyclone dust collector", author: "Robert Witter et al.", site: "Oneida Air Systems patent index", url: "oneida-air.com/patent-index/us11419467", kind: patent}
• {title: "About Us & Our History", site: "Oneida Air Systems, Inc.", url: "oneida-air.com/about-us", kind: corporate history}
• {title: "Oneida Air Systems Marks 30 Years", author: "Woodworker's Journal staff", site: "Woodworker's Journal", url: "woodworkersjournal.com/oneida-air-systems-marks-30-years", kind: trade press, date: "2023-06-16"}
• {title: "A Revolution in Dust Collection", author: "Asa Christiana", site: "Fine Woodworking", issue: "#223", url: "finewoodworking.com/project-guides/shop-machines/a-revolution-in-dust-collection", kind: trade press, date: "2011-10-27"}
• {title: "Background", author: "Bill Pentz", site: "billpentz.com/woodworking/cyclone/background.php", kind: self-published, note: "respected-amateur tier, flagged as non-peer-reviewed, disputed credentials per LumberJocks thread below"}
• {title: "Dust Collection Basics / Ducting", author: "Bill Pentz", site: "billpentz.com/woodworking/cyclone/ducting.php", kind: self-published, note: "respected-amateur tier"}
• {title: "Is Bill Pentz Dust Collector Safety Exaggerated? (forum)", site: "lumberjocks.com/threads/is-bill-pentz-dust-collector-safety-exaggerated.102298", kind: forum, note: "credential dispute"}
• {title: "Phil Thien's Baffle and Bill Pentz (thread #131889)", site: "Sawmill Creek Woodworking Community", kind: forum, date: "2010-02"}
• {title: "The Story Behind the Original Cyclone Dust Collector Retrofit Baffle", author: "Rain Noe", site: "Core77", url: "core77.com/posts/24161", kind: trade press, date: "2013-01-08"}
• {title: "Thien baffle — design page", author: "Phil Thien", site: "jpthien.com/cy.htm", kind: named-maker, self-published design}
• {title: "Dust Deputy specifications", site: "Oneida Air Systems", url: "oneida-air.com/dust-deputy", kind: corporate/product}
• {tag: "DUST-US325", title: "US Patent 325,521 (read 2026-10-16)", url: "https://patents.google.com/patent/US325521A/en", kind: patent}
• {tag: "DUST-OSHA", title: "OSHA Woodworking eTool, Fire and Explosion", url: "https://www.osha.gov/etools/woodworking/safety-hazards/fire-explosion", kind: safety authority, note: "read 2026-10-16"}
• {tag: "DUST-ONEIDA", title: "Oneida Dust Deputy owner\'s manual", url: "https://www.oneida-air.com/amfile/file/download/file/299/product/2094/", kind: manufacturer manual, note: "read 2026-10-16 (summary of warnings); bucket-collapse and tipping not addressed on the page read"}
• {tag: "DUST-ONEIDA2", title: "Oneida Dust Deputy 2.5 inch product page", url: "https://www.oneida-air.com/cyclones/anti-static-dust-deputy-2-5-inch-diy-cyclone-separator", kind: manufacturer product page, note: "read 2026-10-16"}
• {tag: "DUST-EPA", title: "US EPA, Monitoring by Control Technique: Cyclone", url: "https://www.epa.gov/air-emissions-monitoring-knowledge-base/monitoring-control-technique-cyclone", kind: regulator, note: "read 2026-10-16 (particle density not discussed on that page); the EPA fact-sheet PDF (https://www3.epa.gov/ttn/catc/cica/files/fcyclon.pdf) was not read"}
• {title: "NIOSH, Control of Wood Dust From Table Saws", url: "https://www.cdc.gov/niosh/docs/hazardcontrol/hc10.html", kind: safety authority, note: "not fetched; relayed from the reviewer"}
• {title: "Cyclone separators in grain/agricultural and industrial processing", site: "CECO Environmental; TDSFluid", kind: trade, note: "not independently fetched this run"}
• {title: "Dust Collector (Haft Tool Corpus — sibling entry)", url: "internal corpus file, the reviewer Processed Originals/Dust Collector", kind: reference}
• {title: "Shop Vacuum (Haft Tool Corpus — sibling entry)", url: "internal corpus file, Shop Vacuum", kind: reference}
• {title: "Ambient Air Cleaner (Haft Tool Corpus — sibling entry)", url: "internal corpus file, Ambient Air Cleaner", kind: reference}

The reviewer's corrections (13)

• BLOCKER — 1. Separate three different tool/system classes — Exact claim: The title and variations treat “two-stage cyclone / Dust Deputy / Thien baffle” and “stand-alone large-format cyclone” as one tool while the Identity section says the tool has “no motor, no impeller, and provides zero suction by itself.”
• BLOCKER — 2. Correct the metal/impeller/spark path — Exact claim: “Any steel screw or nail picked up hits the impeller and can put a spark in the collection bin,” followed by “the cyclone's own collection bin is precisely where that spark lands.”
• BLOCKER — 3. Withdraw the claim that static ignition is largely mythologized — Exact claim: “Static-electricity ignition — flagged as largely mythologized rather than a confirmed hazard, on Pentz's own authority,” supported by an anecdote that he used PVC duct without incident.
• BLOCKER — 4. Add the manufacturer's prohibited-material and combustible-dust controls — Exact claim: The safety section focuses on ferrous metal and duct-pile buildup while the Variations and Trades sections extend the family to grain, cement, mining, and general industrial use.
• BLOCKER — 5. Remove Pentz's 1,000 CFM/7-inch figures as a universal cyclone threshold — Exact claim: “Bill Pentz's own benchmark for genuine fine-dust-level separation is roughly 1000 CFM through 7-inch ducting,” treated as a threshold separating genuine fine-dust performance from basic chip separation.
• SHOULD-FIX — 6. Correct the “100% fine-dust bypass” and coarse-only claims — Exact claim: “Traditional cyclone designs pass 100% of the airborne dust right through,” and the repeated framing of every cyclone as only a “chip-and-coarse-debris separator.”
• BLOCKER — 7. Add pressure-loss, airtightness, receptacle-collapse, and stability hazards — Exact claim: Installation is “straightforward for a beginner” because the tool is “passive” with “no moving parts.”
• SHOULD-FIX — 8. Do not imply a separator alone protects the impeller in every architecture — Exact claim: The cyclone universally drops material “before that debris ever reaches the machine doing the suction,” thereby protecting the impeller from chip impact.
• SHOULD-FIX — 9. Reframe the Finch patent as a milestone, not the founding patent — Exact claim: “Industrial cyclone separation, verified directly to an 1885 patent,” called the “founding patent” and “the cyclone principle stated in a primary source.”
• SHOULD-FIX — 10. Stop treating search links and citations as proof of lineage — Exact claim: Google Patents “Similar Documents” establishes a Knickerbocker “company R&D program,” and a “forward-citation chain” is presented as a genuine multi-decade, cross-industry lineage record.
• SHOULD-FIX — 11. Remove the unsupported carcinogen/adoption causal claim — Exact claim: Fine Woodworking's 2011 article “ties consumer adoption of cyclone pre-separation directly to wood dust's 2002 U.S. carcinogen listing.”
• SHOULD-FIX — 12. Tighten claims about Thien, ClearVue, trademarks, and negative searches — Exact claim: Thien is called “the tool's own inventor”; Dust Deputy is said to be “the origin of the generic small-shop term”; Pentz's account and a company social post are framed as a ClearVue founding conflict; no museum record is presented as a “genuine absence.”
• MINOR — 13. Remove internal generation provenance from the publishable entry — Exact claim: The entry names “dual research passes legwork,” “synthesized and judged by Hewn,” and a “dedicated reconnaissance research passes.”