# Oscillating Mortiser (Swing-Chisel Mortiser) Hewn Tool Library · https://hewn.build/tools/oscillating-mortiser-swing-chisel-mortiser Corrected: An independent reviewer read this entry and found corrections. They have been applied to the text, and the reviewer re-checked the correction that mattered most for safety and found it done; the others have not been re-checked yet. The list at the end is the record of what changed. Cite as: "Oscillating Mortiser (Swing-Chisel Mortiser)." Hewn Tool Library, hewn.build/tools/oscillating-mortiser-swing-chisel-mortiser. Reviewed 2026-08-03. --- ## Identity - **name:** **swing-chisel mortiser** (also: oscillating-chisel mortiser). "Cycling mortiser" is not used as a synonym — many unrelated automatic machines cycle (the reviewer mechanical notes). - **family / category:** Powered mortising machines, alongside hollow-chisel, oscillating-slot, chain and router/CNC mortisers as sibling mechanisms (review fix 14). - **one-line (review fix 7):** a shaped mortising chisel oscillates rapidly along an adjustable closed/elliptical path while the head is fed into the clamped work. Feed and cycle automation depend on the machine. - **★ four mechanisms, defined by what moves (review fix 3):** | Machine | What rotates / oscillates / traverses / vibrates | Typical result | |---|---|---| | **Swing-chisel mortiser** (this entry) | a shaped chisel/tool **oscillates on a closed or elliptical path**; head or work is fed | mortise profile set by tool shape and stroke | | **Oscillating slot mortiser** (e.g. Cantek SW-02, D-Mac DMT-120) | a **rotating cutter traverses automatically** back and forth while feeding; separate spindle and oscillation drives on the DMT-120 | slot with ends normally radiused to cutter diameter | | **Manual horizontal slot mortiser** | a rotating cutter; slot formed by **operator-controlled** table/head motion | radiused-end slot; not "oscillating" merely because it is horizontal | | **Vibratory hollow-chisel mortiser** (e.g. Wadkin DM/V) | hollow square chisel around an auger descends essentially **straight**, with vibration/hammer action assisting penetration | square-cornered mortise | Chain mortisers (chain and bar) are a fifth sibling ([[Chain Mortiser]]). - **match by mechanism, not by the word "oscillating."** The trade uses the word for more than one machine class. - **⚠ sibling-entry note (carried, not executed).** The [[Hollow-Chisel Mortiser]] entry's "Multico T-5 oscillating mortiser" citation could not be confirmed: Multico's catalog PDF (via scosarg.com) is headed "MULTICO HOLLOW CHISEL MORTISER." Record Power's DML305/DML320 are lathes; its BM16 is a hollow-chisel bench mortiser (retailer listings only). Correction of the sibling entry is left to review. --- ## ✦ How NOT to use it - **not-for:** occasional or one-off mortising where a hollow-chisel, router or hand method is adequate; any job outside the machine's and tooling's stated capacity. - **dangerous (review fix 11 — the holding finding).** These are established machine hazards; no accident report is needed to identify them. - **Point of operation** — a rapidly oscillating cutter: severe cuts and amputation (WorkSafe NZ). Guarded point of operation; hands out of the tool path; use the designed clamp and stops. - **Reciprocating head and automatic clamp** — crushing and entanglement (OSHA rotary/reciprocating guidance). Hands out of the clamp path; guards and interlocks working. - **Foot control** — does not separate hands from the danger zone and can be actuated inadvertently (OSHA foot-control guidance). Guard and position it; verify single-cycle/anti-repeat behavior and the emergency stop. - **Moving timber** — long or irregular stock can swing or be ejected. Support it; clamp it. - **Stored energy** — pneumatic and hydraulic pressure can move the head or clamp after power is off. Release or block it and verify zero energy before access. - **Electrical** — competent installation and phase conversion. - **Dust, chips and noise** — extraction; assessed eye, hearing and respiratory protection; no compressed-air personal cleaning. - **Bypassing safeguards** — never defeat guards, pressure switches, interlocks or limit switches. Mayer's 1959 patent already included a carriage limit switch; that shows safeguarding was part of the design problem, not that a surviving machine still has adequate modern controls. - **Used, modified or long-idle machines** — competent inspection before operation. - **damaging:** Holcombe's log records that on his SM6-PII the chisel holder's flush-head bolts had been replaced with protruding, wrong-size imperial Allen bolts that crashed into the table, bending the chisel seat, scarring the table and ruining the threads — wrong hardware in a moving assembly. Use the maker's specified fasteners and tooling. - **beginner-trap:** assuming one model's controls (foot pedal, single automatic stroke) apply to every swing-chisel machine; assuming hollow-chisel setup habits (bit-to-chisel clearance) carry over; assuming square ends or end-grain capability without checking tooling and setup. A Festool Owners Group aside about forgetting overlapping passes on a shop-built rig is banter, not evidence. - **lineage-misuse:** buying or specifying "an oscillating mortiser" without checking which mechanism is meant (swing-chisel, oscillating slot, vibratory hollow-chisel); assuming tooling is interchangeable across them — swing-chisel tooling is described in the trade record as much more expensive than hollow-chisel or slot tooling. --- ## Correct use - **The mechanical job (review fix 7):** the shaped chisel oscillates rapidly on its adjustable path while the head is fed into the clamped work; the path helps it cut the profile and expel chips. Whether one automatic stroke or a sequence completes the mortise depends on the machine. - **Before first use — a model-specific safety gate (review fix 11):** 1. Obtain the **exact manufacturer/model manual**, tooling data, and wiring and pneumatic/hydraulic diagrams. 2. Have **installation, anchoring, phase conversion, guarding and repairs** handled by competent people; have any **used, modified, incomplete or long-idle machine competently inspected** before recommissioning (review fix 12). 3. Confirm **point-of-operation, drive and reciprocating-part guards** are fitted and working (OSHA woodworking rotary/reciprocating guidance). 4. Confirm the **clamp, stops, emergency stop, interlocks, limit and pressure switches, and single-cycle/anti-repeat behavior** work as designed, where fitted. 5. Position and **guard the foot control** against unintended actuation (OSHA: a foot control does not keep hands out of the danger zone and can be activated inadvertently). 6. Arrange **chip/dust extraction**, and assess **eye, hearing and respiratory protection**. 7. Operators are **trained and authorized**. - **In operation:** secure the work in the designed clamp against the stops, with support for long or irregular stock; keep hands out of the cutter and clamp paths; never bypass guards, pressure switches, interlocks or limit switches; do not use compressed air to blow off clothing or skin, or to scatter chips. - **Lock out:** before setup beyond normal controls, cleaning inside the danger zone, jam clearing, tooling changes or repair — isolate and lock out electrical power, **release or block pneumatic and hydraulic stored energy**, and verify zero energy (WorkSafe NZ; OSHA). - **Speed and fatigue.** Practitioners report a large speed and fatigue advantage over a hollow-chisel machine for volume mortising (Woodweb 2009; Sawmill Creek). Whether mortise ends are fully square or need clipping is disputed between owners and depends on tooling and setup. - **End grain (review fix 9): unresolved, model/tool/material-dependent.** One 2006 Woodweb contributor reports these machines "have a hard time on end grain (teak in particular)"; another Woodweb discussion says they can mortise end grain. Neither is a corpus exclusion without toolmaker guidance or controlled evidence. --- ## ✦ Matching — for the app's read - **strong positive signals:** swing chisel; oscillating chisel carrier; shaped chisel on a closed/elliptical path; MAKA SM/DB/RDB/RSE/STV; Lari & Lari / Deltawood swing-chisel; Centauro BETA; oscillating mortising chisels specified by machine holder and mortise dimensions. - **separate-tool signals:** rotating cutter + traversing carriage/head + radiused ends → **oscillating slot mortiser**; square hollow chisel around an auger → **hollow-chisel mortiser**; vibration-assisted straight hollow-chisel feed → **vibratory hollow-chisel**; chain and bar → **chain mortiser**. - **do NOT hard-code:** foot pedal, air-over-hydraulic feed, three-phase supply, one complete automatic stroke, orientation, single head, square ends, or inability to cut end grain. All vary by model, tooling or setup. - **does:** cuts mortises with an oscillating shaped chisel, at production speed on suitable machines. - **suits:** repeated production mortises in doors, windows, gates, fence posts, furniture and joinery parts — after checking stock, species, grain direction, mortise geometry, depth and throughput against the machine and tooling specifications. - **kit-fit:** - **pairs with:** mortise-and-tenon joinery; dust extraction; the model's tooling set. - **substitutes and overlaps (review fix 10):** hollow-chisel, manual or automatic slot, chain, router/CNC and hand-cut methods occupy overlapping roles. Compare resulting profile, cutter type, end shape, depth, work orientation, setup, throughput, tooling cost, and whether the mating tenon's corners must be rounded or relieved. A slot mortiser can cut the mortise for an **integral** tenon or a **loose** tenon; radiused ends do not force a loose-tenon strategy. - **cannot replace:** the operator's joint layout and judgment. - **access:** usually industrial. Weight, guarding, controls, air/hydraulic requirements, tooling and support availability, transport, installation and operator competence determine access more than three-phase power alone. Not a typical first or hobby mortiser. Prices are not given as current. - **revival:** used MAKA machines are bought and restored as production assets (Holcombe). Restoration of safety-critical guarding, controls, pressure systems and electrics requires competent assessment against the correct manual and applicable law; a restorer's modifications are not a template (review fix 12). --- ## Anatomy (family-level, review fix 6) Defined by **oscillating/swinging chisel motion**, not by any one model's controls. - **Oscillating tool carrier** — moves a shaped chisel/tool along a closed or approximately oval path whose stroke can be adjusted (Maurer; Mayer). - **Feed** — the head or work is fed into the clamped stock. Feed type is a variant field (below). - **Workholding** — an integrated clamp and stops; Mayer's patent includes workholding. - **Tooling** — profile set by the chisel. Monobloc, ALTERNAX, double/triple, haunch, air-assist, HSS, carbide and cobalt options are toolmaker- and machine-specific. Some multi-chisel arrangements are used to shape mortise ends/corners; the "mortise end/corner profile" depends on tooling and setup. - **Not drill-press-framed.** That description belongs to the hollow-chisel subfamily. --- ## Variations (living) — variant fields, not family identity | Field | Values seen in the sources | |---|---| | feed | manual hand lever (Mayer 1959; manual benchtop variants per practitioners); pneumatic; air-over-hydraulic (Holcombe's SM6-PII) | | control / cycle | foot-pedal single cycle (some MAKA models); multi-head automatic; CNC (Deltawood RD3C-A, Centauro BETA) | | orientation | vertical; horizontal (Centauro BETA) | | heads | single; multi-head (Deltawood LB3/RD3C) | | power | three-phase common on industrial machines; not a defining field | - **MAKA SM6/SM6-PII/SM7/DB/RDB/RSE/STV** (Germany, 1952–2009). Used examples circulate. - **Lari & Lari → Deltawood** (Italy); **Centauro BETA** (CNC horizontal). Dated as above. - **ALTERNAX** tooling and multi-chisel configurations — toolmaker- and machine-specific. - **Not members:** oscillating slot mortisers (Cantek SW-02, D-Mac DMT-120), Wadkin DM/V (vibratory hollow-chisel), manual slot mortisers. --- ## Trades - **Door, window and joinery production**, especially in Continental Europe (MAKA, Lari & Lari/Deltawood, Centauro). - **Furniture and millwork shops** via the used industrial market (Holcombe's Lancaster, PA machine). - **Gates, fence posts and furniture parts** in repeat production. --- ## Lineage - **The documented patent lineage begins with Maurer (review fix 1).** **US 2,311,451, "Mortising machine," Gottfried Maurer** — Swiss priority 1940, published in the United States in 1943 — describes an oscillating tool carrier that moves the mortising tool along a closed curve or ellipse, with adjustable geometry, work clamping and chip expulsion. It is not a vague prior art; it is the swinging-carrier mechanism. - **Mayer (US 2,895,516).** "Oscillating Adjustable Stroke Mortising Machine," Max Mayer, Neu-Ulm, Germany; **filed January 5, 1956; published July 21, 1959.** It cites Maurer and develops an adjustable-stroke production machine: an approximately oval tool path, interchangeable tool profiles, integrated workholding, a hand-lever-lowered carriage, and a limit switch intended to stop the motor when the carriage is raised. It is later commercial development and refinement, not the founding invention. - **DE 919,664 is not a family member (review fix 2).** It appears in US 2,895,516's cited prior art, has a 1952 priority, and is attributed to Adolf Bäuerle Maschinen und Werk (a swiveling chain-milling machine). US 2,895,516's family table lists only the US application. Its relevance is not explained here because it was not inspected. - **MAKA's 1952 milestone.** MAKA's own history and Höchsmann's WOOD TEC PEDIA place MAKA's founding and an oscillating-mortiser patent milestone in **1952**. The 1952 patent number is not identified; no priority claim is made from it. - **Chip expulsion, not a jam story (review fix 8).** Mayer lists rapid repeat production, adjustable stroke, interchangeable shapes, workholding and chip expulsion as objectives; Maurer compares chains, drills and square-gouge systems. Chip expulsion is an explicit design objective and reduced chip accumulation a mechanical benefit. Any comparison with hollow-chisel jamming is **modern inference**, not the invention's documented origin. - **Descendants and continuation (review fix 4).** **MAKA stopped mortiser production on March 31, 2009**, with Degema taking over relevant carpentry machines and spares (Höchsmann). The mechanism did not end there: **Deltawood** — trade sources describe it as replacing or continuing the **Lari & Lari** line — offered LB3/RD3C multi-head swing-chisel machines and a CNC RD3C-A (Woodworking News, 2021; JJ Smith), and **Centauro's BETA** is a CNC horizontal swing-chisel mortiser (JJ Smith). JJ Smith listed a Deltawood LB3T in stock in **March 2023**. Current tooling sources offer oscillating-chisel types including ALTERNAX and multi-chisel configurations. **These are dated snapshots; current status of any model should be rechecked before it is called current.** - **Contemporaries:** oscillating slot, manual slot, vibratory hollow-chisel and chain mortisers — see the table above. --- ## History - **Swiss/German patent record, then German production.** Maurer's 1940 Swiss priority (US 1943); MAKA (Max Mayer Maschinenbau, Neu-Ulm/Nersingen) from 1952; Mayer's US filing 1956, published 1959. MAKA's line (SM, DB, RDB, RSE, STV series) ran until 2009. - **Italian line.** **Lari & Lari** (Italy) made swing-chisel mortisers; a 2006 Woodweb poster's "Larick & Larick" is an apparent misspelling of it (review fix 5). Deltawood continued the line. - **A dated machine in American use.** Brian Holcombe's restoration of a **1984 MAKA SM6-PII** from a window-frame production shop in Lancaster, PA. - **Wadkin DM/V (UK) — archived model (review fix 13).** Wadkin's DM/V page sits in its archive and links historical literature and manuals; it supports model identity and archived specifications, not current new manufacture. Wadkin literature shows different power figures and configurations across documents (including older 1.5 kW and single-phase options); each specification should be attributed to its exact leaflet. Wadkin's archive page claims the vibratory head reduces operator effort by 66% compared with conventional chisel mortisers — manufacturer copy, not independently measured. --- ## ✦ Human side - **Brian Holcombe** (furniture maker, Princeton, NJ) — a named, photographed account of restoring a 1984 MAKA SM6-PII. **Observed on one heavily rebuilt and modified machine** (review fix 12): extensive non-factory machining, replacement pneumatic components, a new fence, a modified chip-breaker system. It is excellent object history, not an OEM manual or a validated safety configuration. - **Woodweb trade forum** — "Mortising Machine Options" (2006, https://www.woodweb.com/knowledge_base/Mortising_Machine_Options.html): posters discuss a roughly $15,000 1980s price, MAKA availability, Lari & Lari ("Larick & Larick" in the original) and the Wadkin DM/V. A 2009 Woodweb thread, "Shopping for Mortising Machinery," carries posters describing the type as much faster than a hollow-chisel machine for volume work, tooling as "very expensive compared to a hollow chisel machine or slot mortiser," and a live disagreement over whether mortise ends come out square. **Practitioner evidence only** (review fix 15); the 2009 thread's URL was not recorded at build and is not re-derived here. - **Sawmill Creek** — Chris Fournier: "This machine will make you think of all the time that you struggled with your hollow chisel mortiser." Thread URL not recorded at build; practitioner evidence. --- ## ✦ Proof of existence - **US 2,311,451**, Gottfried Maurer, 1940 Swiss priority, US publication 1943 — primary; oscillating tool carrier on a closed curve/ellipse. HIGH. - **US 2,895,516**, Max Mayer, filed Jan. 5, 1956, published Jul. 21, 1959 — primary; cites Maurer. HIGH. - **MAKA history** and **Höchsmann WOOD TEC PEDIA** — 1952 founding/patent milestone; mortiser production ended Mar. 31, 2009; Degema took over spares. MEDIUM (company self-history and a manufacturer encyclopedia; the 1952 patent not identified). - **Holcombe's 1984 MAKA SM6-PII** — a dated, photographed, modified machine. HIGH that it exists and for his observations. - **Deltawood and Centauro** — JJ Smith (2021–2023) and Woodworking News (2021). MEDIUM, dated. - **Museum record:** none naming a swing-chisel mortiser was found in the sources used for this entry. --- ## References | Tag | Source | Supports | |---|---|---| | OM-M | US 2,311,451, "Mortising machine," Gottfried Maurer — https://patents.google.com/patent/US2311451A/en | 1940-priority oscillating tool carrier, closed/elliptical path, clamping, chip expulsion | | OM3 | US 2,895,516, "Oscillating Adjustable Stroke Mortising Machine," Max Mayer — https://patents.google.com/patent/US2895516A/en | 1956 filing, oval path, interchangeable tooling, hand-lever carriage, limit switch; cites Maurer; family table excludes DE 919,664 | | OM1 | MAKA Systems, History — https://www.maka.com/en/historie | 1952 founding/patent milestone (company self-history) | | OM2 | Höchsmann WOOD TEC PEDIA, "MAKA" — https://wtp.hoechsmann.com/en/lexikon/7509/MAKA | 1952 milestone; Mar. 31, 2009 end of mortiser production; Degema | | OM7 | Brian Holcombe, "Maka SM6-PII Resto-Mod" — https://brianholcombewoodworker.com/maka-sm6-pii-resto-mod/ | one modified 1984 SM6-PII; air-over-hydraulic feed, foot pedal, pneumatic clamp; wrong-bolt damage | | OM-J1 | JJ Smith, "Reduce bottlenecks with mortising solutions" — https://www.jjsmith.co.uk/news/reduce-bottlenecks-with-mortising-solutions-from-jj-smith | Centauro BETA CNC; Deltawood LB3 | | OM-J2 | JJ Smith, "New stock, March 2023" — https://www.jjsmith.co.uk/news/new-stock-march-2023 | Deltawood LB3T in stock, March 2023 (dated snapshot) | | OM-WN | Woodworking News, "Deltawood high-production mortising machines" (2021) — https://www.woodworkingnews.co.uk/deltawood-high-production-mortising-machines-%E2%80%93-now-available-jj-smith | Deltawood continuing Lari & Lari; multi-head and CNC models | | OM-C | A.W. Machinery, Cantek SW-02 Oscillating Slot Mortiser — https://www.awmachineryllc.com/products/double-table-oscillating-mortiser/ | oscillating slot class: traversing rotating cutter, pneumatic clamp, safety and pressure switches | | OM-D | JJ Smith, D-Mac DMT-120 Twin Table Slot Mortiser — https://www.jjsmith.co.uk/new-machinery/d-mac-dmt-120-twin-table-slot-mortiser | oscillating slot class; separate spindle and oscillation motors | | OM5 | Wadkin, DM/V Mortiser (archive) — https://www.wadkin.com/wadkin-dm-v-mortiser | vibratory hollow-chisel mechanism; archived specifications; 66% claim (manufacturer copy) | | OM-O1 | OSHA eTool, Woodworking — rotary and reciprocating hazards — https://www.osha.gov/etools/woodworking/machine-hazards/rotary | guarding, training, inspection, housekeeping | | OM-O2 | OSHA eTool, Machine guarding — foot control — https://www.osha.gov/etools/machine-guarding/presses/foot-control | foot controls do not keep hands out; inadvertent activation (principle transferred, press rules not copied) | | OM-W | WorkSafe New Zealand, Mortisers — https://www.worksafe.govt.nz/topic-and-industry/machinery/woodworking/mortisers/ | cutting/amputation, moving timber, dust, noise, clamping, lockout (examples are hollow-chisel and chain machines) | | OM8 | Woodweb, "Mortising Machine Options" (2006) — https://www.woodweb.com/knowledge_base/Mortising_Machine_Options.html | practitioner: price, Lari & Lari (misspelled), Wadkin DM/V, teak end-grain report | | OM9 | Woodweb, "Shopping for Mortising Machinery" (2009) — URL not recorded | practitioner: speed, tooling cost, square-end dispute | | OM14 | Sawmill Creek, Chris Fournier — URL not recorded | practitioner: speed | | OM11 | Multico range PDF via scosarg.com | Multico machines are hollow-chisel (sibling-entry note) | | OM12 | Record Power BM16 retailer listings | BM16 is hollow-chisel (sibling-entry note) | | OM16 | [[Hollow-Chisel Mortiser]] (corpus) | cross-reference | | *Removed* | Wikipedia "Mortiser" as evidence about trade taxonomy (review fix 15); DE 919,664 as a family member (fix 2); OM10 Festool banter as a source | — | --- ## The reviewer's corrections (16) - `BLOCKER` — 1. Correct the pre-MAKA lineage — Exact claim: “the founding invention” and “No pre-1952 prior-art patent for an oscillating-chisel mechanism specifically was located this run.” - `BLOCKER` — 2. Remove the false German patent-family identification — Exact claim: “a related German patent family member DE 919664 C” and “almost certainly the US filing of the same German invention.” - `BLOCKER` — 3. Separate swing-chisel and oscillating-slot machines correctly — Exact claim: A horizontal slot mortiser is one of three machines called oscillating even though it “involves no oscillation at all — a constantly rotating spindle.” - `BLOCKER` — 4. Remove the false no-current-production claim — Exact claim: “None of the true swing-chisel machines documented this run are in current production” and “the true swing-chisel mechanism does not appear to have a modern CNC-era successor.” - `SHOULD-FIX` — 5. Correct “Larick & Larick” and its status — Exact claim: “Larick & Larick” and “current status not independently re-verified.” - `BLOCKER` — 6. Stop universalizing the MAKA SM6-PII feed system — Exact claim: “a self-cycling mortising machine” with a “single foot-pedal press” and an air-over-hydraulic plunge as defining anatomy. - `SHOULD-FIX` — 7. Correct the motion description — Exact claim: “the chisel swings in an arc during the plunge” and “cuts a complete mortise in one automated stroke.” - `SHOULD-FIX` — 8. Remove the unsupported hollow-chisel-jam origin story — Exact claim: “the failure being solved is chip-packing and binding during the plunge — precisely the failure… endemic to the plain hollow-chisel plunge.” - `SHOULD-FIX` — 9. Rebuild the end-grain guidance — Exact claim: “End-grain mortising… [is] a genuine limitation” and the machine is “not-for” end grain, “teak specifically named.” - `SHOULD-FIX` — 10. Correct the slot-mortiser substitution boundary — Exact claim: A horizontal slot mortiser is “a different joint strategy — loose tenon vs. this machine's integral square mortise.” - `BLOCKER` — 11. Replace the thin safety section with a machine-safety system — Exact claim: “A real mechanism-based hazard… LOW-MEDIUM confidence” followed mainly by air, hydraulic, and unintended-actuation inference. - `SHOULD-FIX` — 12. Do not present restoration modification as operating instruction — Exact claim: Holcombe's restoration is used as the main anatomy and misuse authority, while the entry frames revival as merely acquiring a production asset. - `SHOULD-FIX` — 13. Correct the Wadkin current-market claim and specifications — Exact claim: “Currently sold through Wadkin's ‘Classical’ trade line” and a single fixed specification set. - `SHOULD-FIX` — 14. Fix internal family and schema contradictions — Exact claim: Frontmatter says “the drill-press-framed family,” while anatomy says the swing-chisel machine is “not built on a drill-press frame.” - `SHOULD-FIX` — 15. Repair source traceability — Exact claim: Several references are listed only as “search-and-read level,” a forum name, or a corpus cross-reference without a direct URL. - `SHOULD-FIX` — 16. Lower and split the confidence grade — Exact claim: “effective: MEDIUM-HIGH.”