diff --git a/Firmware/simulator/README.md b/Firmware/simulator/README.md
index 7699f55..c38872f 100644
--- a/Firmware/simulator/README.md
+++ b/Firmware/simulator/README.md
@@ -29,7 +29,7 @@ One row per day, in short; the details are in the sections of this file (the lin
 
 | Date | What changed |
 |---|---|
-| 13 Nov 2026 | **Set up AgOpenWeb from your measures** (version 1.7): the measured noses of the Maxxum (1 m), the Farmall (0.85 m) and the Puma (1.1 m), the boom 2.1 m ahead, Renato's one-axle manure spreader ([the page](#set-up-agopenweb-from-your-measures)). |
+| 13 Nov 2026 | **Set up AgOpenWeb from your measures** (version 1.8): measured noses (Maxxum 1 m, Farmall 0.85 m, Puma 1.1 m), the boom 2.1 m ahead, Renato's one-axle manure spreader, his centre-pivot mower ([the page](#set-up-agopenweb-from-your-measures)). |
 | 12 Nov 2026 | **Set up AgOpenWeb from your measures** (version 1.5): buttons for Renato's Farmall 115C, Maxxum 135 and Puma 180; a drawbar implement takes the tractor's pin ([the page](#set-up-agopenweb-from-your-measures)). [Action](#how-it-is-built) on `ubuntu-26.04`. |
 | 11 Nov 2026 | `build.py` leaves the pages' own build date (`PAGE_BUILT`) empty, so the pages' new "is this the running firmware's page" check stays off here. The pretend Keya reports its current in amps, the kickout sensor. |
 | 10 Nov 2026 | Teensy page: the pretend UM982 reports its temperature (59 °C, from `HWSTATUSA`) and the module's name on the network reads `AiO-3F2A`, as the firmware now does. |
@@ -65,7 +65,7 @@ To run it on your own computer: `python3 Firmware/simulator/build.py` and open `
 
 ## Set up AgOpenWeb from your measures
 
-**https://renatorgr.github.io/Boards/aow-settings/** is not a module page: a calculator. Choose the machine (a tractor, an articulated one that bends at its joint, a harvester steered from the back, each with its own turning geometry), type its wheelbase, the angle on the stop and the overhang, and the implement as AgOpenWeb's Tool page has it (front fixed, rear fixed, trailing or TBT, the sections and their width, the overlap, the tool offset, the hitch, trailing hitch and pivot distances, the implement length), and it suggests what to put in AgOpenWeb's Vehicle & Tool page, each value with its reason, and draws the turn from above: the U-turn radius, the turn style and the rows to skip, the distance from boundary, the headland width, the extension, the Go around radius and the tramline passes. Three tractor buttons, by power, fill in Renato's Case IH Farmall 115C (2.3 m, about 45°, 540/65 R34 tyres, its drawbar pin 0.74 m behind the rear axle), his Maxxum 135 (2.7 m, 42°) and his Puma 180 CVX (2.88 m and 33° from its manual's turning circle, 2 m track, 650/65 R42 tyres, its pin 0.9 m back, its front quick hitch 1.1 m ahead of the front axle); an implement on the drawbar moves to the chosen tractor's pin. It opens on the Maxxum with his 8 m sprayer on the front linkage, the boom 2.1 m ahead of the front axle; a second button fills in his semi-mounted 3 m no-till drill (its pivot behind the lower links, its wheels behind the discs). Renato's manure spreader has one axle 4.2 m behind the drawbar pin and its body ends 1.5 m past the axle. Two more buttons have typical measures: a trailed disc harrow and a 4-furrow reversible plough on the 3-point linkage, drawn with a K-turn since a plough skips no rows. A long implement's rear corner (its length) is followed through the turn too: a K-turn backs it towards the edge first. A trailed implement's drawbar must stay off the rear tyres: from the hitch pin, the drawbar's width, the rear track and the tyres' width and height, the page finds the angle where the drawbar touches a tyre and keeps the turn 5° under it; the tyre counts at the drawbar's height (a field, 0.5 m by default), where it is shorter than at its axle, so the drawbar touches it later than the whole wheel would say. A drawbar pin inside the tyres' back edge touches them long before 90° and then sets the radius; a semi-mounted implement's pivot, further back, does not, but its own stop may: a field takes the most the drawbar may turn to each side, from its stop or from what the farmer knows. Two more buttons hold Renato's quick disc harrow on the 3-point linkage and his semi-mounted roller (120° of swing in all), their measures guessed until he takes them. A rigid implement is measured with a tape from the axle nearest to it (a front sprayer from the front axle); AgOpenWeb measures it from the pivot, so for a front implement on a tractor the page adds the wheelbase and shows the hitch length to type in.
+**https://renatorgr.github.io/Boards/aow-settings/** is not a module page: a calculator. Choose the machine (a tractor, an articulated one that bends at its joint, a harvester steered from the back, each with its own turning geometry), type its wheelbase, the angle on the stop and the overhang, and the implement as AgOpenWeb's Tool page has it (front fixed, rear fixed, trailing or TBT, the sections and their width, the overlap, the tool offset, the hitch, trailing hitch and pivot distances, the implement length), and it suggests what to put in AgOpenWeb's Vehicle & Tool page, each value with its reason, and draws the turn from above: the U-turn radius, the turn style and the rows to skip, the distance from boundary, the headland width, the extension, the Go around radius and the tramline passes. Three tractor buttons, by power, fill in Renato's Case IH Farmall 115C (2.3 m, about 45°, 540/65 R34 tyres, its drawbar pin 0.74 m behind the rear axle), his Maxxum 135 (2.7 m, 42°) and his Puma 180 CVX (2.88 m and 33° from its manual's turning circle, 2 m track, 650/65 R42 tyres, its pin 0.9 m back, its front quick hitch 1.1 m ahead of the front axle); an implement on the drawbar moves to the chosen tractor's pin. It opens on the Maxxum with his 8 m sprayer on the front linkage, the boom 2.1 m ahead of the front axle; a second button fills in his semi-mounted 3 m no-till drill (its pivot behind the lower links, its wheels behind the discs). Renato's manure spreader has one axle 4.2 m behind the drawbar pin and its body ends 1.5 m past the axle. His 3.2 m centre-pivot mower conditioner, on the lower links with its swivel between the rear tyres and swung in the turn, presses the Farmall it works with. Two more buttons have typical measures: a trailed disc harrow and a 4-furrow reversible plough on the 3-point linkage, drawn with a K-turn since a plough skips no rows. A long implement's rear corner (its length) is followed through the turn too: a K-turn backs it towards the edge first. A trailed implement's drawbar must stay off the rear tyres: from the hitch pin, the drawbar's width, the rear track and the tyres' width and height, the page finds the angle where the drawbar touches a tyre and keeps the turn 5° under it; the tyre counts at the drawbar's height (a field, 0.5 m by default), where it is shorter than at its axle, so the drawbar touches it later than the whole wheel would say. A drawbar pin inside the tyres' back edge touches them long before 90° and then sets the radius; a semi-mounted implement's pivot, further back, does not, but its own stop may: a field takes the most the drawbar may turn to each side, from its stop or from what the farmer knows. Two more buttons hold Renato's quick disc harrow on the 3-point linkage and his semi-mounted roller (120° of swing in all), their measures guessed until he takes them. A rigid implement is measured with a tape from the axle nearest to it (a front sprayer from the front axle); AgOpenWeb measures it from the pivot, so for a front implement on a tractor the page adds the wheelbase and shows the hitch length to type in.
 
 The rules are AgOpenWeb's own (its `SagittaTurnGeometry`, `YouTurnCreationService` and `VehicleToolLimits`): the turn is drawn by the tractor's pivot, which must stay inside the field edge pulled in by the distance from boundary; a pass closer than twice the radius needs a loop (Sagitta or Keyhole), skipped rows or a K-turn (AgOpenWeb drives a 126° arc and a straight tail; as soon as the tractor reverses the turn is over for AgOpenWeb and its guidance is on the next pass, backing up too, so the tractor backs up until it is on that pass and straight; a trailed implement that would jackknife backing up gets no K-turn), a pass at twice the radius or more gets a plain semicircle. The radius is 1.2 × the tightest the machine can do (wheelbase ÷ tan of the steering angle; an articulated machine (wheelbase ÷ 2) ÷ tan of half the articulation angle), never under 4 m; the distance from boundary keeps what sweeps the widest in the turn, the outer corner of the tractor's nose (half the machine's width, from its rear track and tyres, out from the centre line) or the implement's outer end, a safety margin inside the edge (1 m by default, a field of the page: more where the edge is irregular); each turn is followed step by step every 10 cm, with the implement (a trailed one following its hitch without side slip) and the machine's far end, and the headland is the turn's depth plus that distance plus how far back into the field anything not yet straight on a pass reaches (the implement finishing its pass, a front implement or a trailed one until it is straight on the next pass, a K-turn's tail), in whole passes. The drawing shows the pivot's path, both ends of the implement and the outer corner of the machine's far end. What is not geometry (the section timing, the steering gains, the antenna position) is not suggested.
 
diff --git a/Firmware/simulator/aow-settings/index.html b/Firmware/simulator/aow-settings/index.html
index 375ec49..03fd6fd 100644
--- a/Firmware/simulator/aow-settings/index.html
+++ b/Firmware/simulator/aow-settings/index.html
@@ -11,7 +11,7 @@
 <meta name="viewport" content="width=device-width,initial-scale=1">
 <meta name="color-scheme" content="dark light">
 <title>Set up AgOpenWeb from your measures</title>
-<script src="settings.js?v=1.7"></script>   <!-- the version in the address: a browser that kept the old file fetches the new one -->
+<script src="settings.js?v=1.8"></script>   <!-- the version in the address: a browser that kept the old file fetches the new one -->
 <style>
 :root{color-scheme:dark;--bg:#121511;--card:#1b1f1a;--ink:#e7ebe3;--mute:#9aa395;--line:#2e352b;--warn:#ffb74d;--acc:#8cc068;--accInk:#10140f;--soft:#232a21;--pass:#4a5a44;--fence:#e06c5a;--tool:#6aa4d9}
 @media (prefers-color-scheme:light){:root{color-scheme:light;--bg:#f2f4ef;--card:#ffffff;--ink:#1c2318;--mute:#5f6b5a;--line:#d4dbcf;--warn:#b45309;--acc:#4c7d2a;--accInk:#ffffff;--soft:#e9eee5;--pass:#b9c7b1;--fence:#c0392b;--tool:#2f6fb0}}
@@ -97,6 +97,7 @@
  <button type="button" data-name="sprayer" onclick="preset('sprayer')">8 m sprayer, front</button>
  <button type="button" data-name="drill" onclick="preset('drill')">3 m no-till drill, semi-mounted</button>
  <button type="button" data-name="spreader" onclick="preset('spreader')">10 m manure spreader, one axle</button>
+ <button type="button" data-name="mower" onclick="preset('mower')">3.2 m centre-pivot mower conditioner</button>
  <button type="button" data-name="harrow" onclick="preset('harrow')">4 m disc harrow, trailed</button>
  <button type="button" data-name="plough" onclick="preset('plough')">4-furrow reversible plough</button>
  <button type="button" data-name="quickHarrow" onclick="preset('quickHarrow')">2.7 m quick disc harrow, 3-point</button>
@@ -132,6 +133,7 @@ <h2>Implement</h2>
   <div class="row" data-for="trailed"><label for="drawbar" id="drawbarLabel">Trailing hitch (m)<small>hitch pin (or pivot) to the implement's wheels; with two axles close together, to the middle between them</small></label><input id="drawbar" type="number" step="0.1" min="0.1" value="2"></div>
   <div class="row" data-for="trailed"><label for="drawbarWidth">Drawbar width (m)<small>its widest in the first metre behind the hitch, where it can reach the rear tyres</small></label><input id="drawbarWidth" type="number" step="0.05" min="0" value="0.3"></div>
   <div class="row" data-for="trailed"><label for="swingDeg">Most the drawbar may turn (°)<small>to each side, against the tractor: a semi-mounted pivot's stop (half its whole swing), or what you know your drawbar takes; 0 = from the rear tyres only</small></label><input id="swingDeg" type="number" step="1" min="0" max="180" value="0"></div>
+  <div class="row" data-for="trailed"><label for="turnSwingDeg">Swing in the turn (°)<small>a centre-pivot implement, such as a mower: how far you swing it against its drawbar in the turn, so the drawbar folds less; 0 = held straight</small></label><input id="turnSwingDeg" type="number" step="1" min="0" max="60" value="0"></div>
   <div class="row" data-for="trailed"><label for="foldClearanceDeg">Room kept before it touches (°)<small>the turn's circle folds the drawbar this much less than the angle where it touches a tyre or its stop: 5° is about 5 to 8 cm at the tyre</small></label><input id="foldClearanceDeg" type="number" step="1" min="0" max="45" value="5"></div>
   <div class="row" data-for="trailed"><label for="pivotToTool">Pivot distance (m)<small>the implement's wheels to the working line; behind them = positive, ahead (wheels at the back) = negative</small></label><input id="pivotToTool" type="number" step="0.1" value="0"></div>
   <div class="row" data-for="notFront"><label for="length">Implement length (m)<small>from its attachment (the 3-point hitch, or its own axle when trailed) to its rearmost point; 0 = not known</small></label><input id="length" type="number" step="0.1" min="0" value="0"></div>
@@ -160,7 +162,7 @@ <h3>Every turn AgOpenWeb can make here, the smallest headland first</h3>
 "use strict";
 const $ = id => document.getElementById(id);
 const F = ["machine", "wheelbase", "steer", "overhang", "mount", "sections", "sectionWidth", "width", "overlap", "offset", "axleToTool", "hitch", "tankHitch", "drawbar", "pivotToTool", "length", "sprayerWidth", "margin",
- "trackWidth", "tyreWidth", "wheelDiameter", "drawbarHeight", "drawbarWidth", "swingDeg", "foldClearanceDeg"];
+ "trackWidth", "tyreWidth", "wheelDiameter", "drawbarHeight", "drawbarWidth", "swingDeg", "turnSwingDeg", "foldClearanceDeg"];
 const LABELS = {   // what the angle and the overhang are on each machine, and which axle is the pivot
  tractor: ["Maximum steering angle (°)", "the front wheels on the stop, what the steer wizard measured", "Front overhang (m)", "front axle to the nose, weights included"],
  articulated: ["Maximum articulation angle (°)", "how far the machine bends at its joint, on the stop", "Front overhang (m)", "front axle to the nose"],
@@ -184,7 +186,7 @@ <h3>Every turn AgOpenWeb can make here, the smallest headland first</h3>
   note: "Renato's Case IH Farmall 115C: 2.3 m wheelbase, 1.7 m rear track, 540/65 R34 rear tyres, the drawbar pin 0.74 m behind the rear axle, its nose 0.85 m ahead of the front axle. About 45° of steering, by eye until a wheel angle sensor measures it: any angle over 35° gives the same turn, AgOpenWeb's 4 m floor."}
 };
 const PRESETS = {
- // the example buttons: Renato's sprayer, drill and manure spreader, measured; a disc harrow and a plough with typical measures; his quick harrow and roller, guessed. `note`: shown under the buttons;
+ // the example buttons: Renato's sprayer, drill and manure spreader, measured; his centre-pivot mower conditioner (`tractor`: the button pressed with it), measured; a disc harrow and a plough with typical measures; his quick harrow and roller, guessed. `note`: shown under the buttons;
  // `turn`: the turn option drawn first (a plough cannot skip rows); `onDrawbar`: its hitch is the tractor's drawbar pin
  sprayer: {mount: "front", sections: 8, sectionWidth: 100, width: 8, overlap: 0, offset: 0, axleToTool: 2.1, hitch: 1, length: 0, sprayerWidth: 8,
   note: "Measured on Renato's sprayer: the 8 m boom on the front quick hitch (1.1 m ahead of the front axle), 2.1 m ahead of the front axle."},
@@ -192,6 +194,8 @@ <h3>Every turn AgOpenWeb can make here, the smallest headland first</h3>
   note: "Measured on Renato's no-till drill: semi-mounted, its pivot 1.54 m behind the rear axle, its wheels 4.15 m behind the pivot and the discs 1.6 m ahead of the wheels. Its pivot is behind the rear tyres' back edge, so the tyres do not limit its turn; its own headstock or stop does: watch how far it folds and type that in 'Most the drawbar may turn'. It never backs up in the ground: no K-turn."},
  spreader: {mount: "trailed", onDrawbar: true, sections: 1, sectionWidth: 1000, width: 10, overlap: 0, offset: 0, drawbar: 4.2, pivotToTool: 1.5, drawbarWidth: 0.3, swingDeg: 0, length: 1.5, sprayerWidth: 0,
   note: "Renato's manure spreader: one axle 4.2 m behind the drawbar pin, the body 1.5 m past the axle with the beaters at its back; it spreads 10 m wide. On the tractor's drawbar, its pin (the tractor button's) near the rear tyres' back edge: the drawbar touches a tyre before 90° (at the drawbar's height, where the tyre is shorter than at its axle), and that sets the radius."},
+ mower: {mount: "trailed", tractor: "farmall", sections: 1, sectionWidth: 320, width: 3.2, overlap: 0.1, offset: 0, hitch: 0.5, drawbar: 6.5, pivotToTool: -2, drawbarWidth: 0.3, swingDeg: 0, turnSwingDeg: 20, length: 0, sprayerWidth: 0,
+  note: "Renato's centre-pivot mower conditioner, used with the Farmall (its button is pressed with it), on the lower links. Measured: its swivel 0.5 m behind the rear axle, between the rear tyres, the wheels 6.5 m behind the swivel, the discs 2 m ahead of the wheels. Held straight, the tongue would touch a tyre at 54.5° and need a 9.1 m radius; swung against the tongue in the turn (20° guessed until he measures it), the tongue folds less and its own length sets the radius. 10 cm of overlap so no strip is left standing. Mowing back and forth it swings to the uncut side, the other side of the tractor every pass: leave the tool offset at 0 (it is drawn in the middle)."},
  harrow: {mount: "trailed", onDrawbar: true, sections: 1, sectionWidth: 400, width: 4, overlap: 0.2, offset: 0, drawbar: 3.5, pivotToTool: 0, drawbarWidth: 0.3, swingDeg: 0, length: 1.5, sprayerWidth: 0,
   note: "Typical measures, change them to yours: on the tractor's drawbar, its pin (the tractor button's) near the rear tyres' back edge; the wheels between the front and the rear gangs, 20 cm of overlap so no strip is missed. With its wheels at the back (a roller), the discs are ahead of them: a negative pivot distance. A semi-mounted harrow's hitch is its pivot, further back."},
  plough: {mount: "rear", sections: 1, sectionWidth: 160, width: 1.6, overlap: 0, offset: 0, axleToTool: 3, hitch: 1, length: 4.5, sprayerWidth: 0, turn: "kturn0",
@@ -207,9 +211,12 @@ <h3>Every turn AgOpenWeb can make here, the smallest headland first</h3>
 
 function preset(name) {
  const p = PRESETS[name];
- for (const [k, v] of Object.entries(p)) if (k !== "turn" && k !== "note" && k !== "onDrawbar") $(k).value = v;
+ for (const [k, v] of Object.entries(p)) if (!["turn", "note", "onDrawbar", "tractor"].includes(k)) $(k).value = v;
+ $("turnSwingDeg").value = p.turnSwingDeg || 0;   // only a centre-pivot implement is swung in the turn
+ implementName = name; $("presetNote").textContent = p.note || ""; chosen = p.turn || "";
+ if (p.tractor && p.tractor !== tractorName) return tractor(p.tractor);   // the tractor it works with: tractor() puts it on that drawbar
  if (p.onDrawbar) $("hitch").value = TRACTORS[tractorName].pin;
- implementName = name; $("presetNote").textContent = p.note || ""; chosen = p.turn || ""; marks(); update();
+ marks(); update();
 }
 function tractor(name) {
  const t = TRACTORS[name];
@@ -229,7 +236,7 @@ <h3>Every turn AgOpenWeb can make here, the smallest headland first</h3>
   sections: n("sections") || 0, sectionWidth: n("sectionWidth") || 0, overlap: n("overlap") || 0, offset: n("offset") || 0, axleToTool: n("axleToTool"), hitchLength: n("hitch"),
   tankHitch: n("tankHitch"), drawbar: n("drawbar"), pivotToTool: n("pivotToTool"), length: n("length") || 0, sprayerWidth: n("sprayerWidth") || 0, margin: n("margin"),
   trackWidth: n("trackWidth"), tyreWidth: n("tyreWidth"), wheelDiameter: n("wheelDiameter"), drawbarHeight: n("drawbarHeight") || 0, drawbarWidth: n("drawbarWidth") || 0, swingDeg: n("swingDeg") || 0,
-  foldClearanceDeg: n("foldClearanceDeg")};
+  turnSwingDeg: n("turnSwingDeg") || 0, foldClearanceDeg: n("foldClearanceDeg")};
 }
 function update() {
  labels();
diff --git a/Firmware/simulator/aow-settings/settings.js b/Firmware/simulator/aow-settings/settings.js
index abb8a81..25830ff 100644
--- a/Firmware/simulator/aow-settings/settings.js
+++ b/Firmware/simulator/aow-settings/settings.js
@@ -12,7 +12,7 @@
 // (Sagitta or Keyhole), a pass at twice the radius or more gets a plain semicircle.
 "use strict";
 (function (root) {
- const VERSION = "1.7";       // shown under the page's title and in index.html's "settings.js?v=": raise both with every change
+ const VERSION = "1.8";       // shown under the page's title and in index.html's "settings.js?v=": raise both with every change
  const RADIUS_FACTOR = 1.2;    // the turn radius over the tightest the tractor can do: the steering stays off its stop
  const RADIUS_FLOOR = 4.0;     // AgOpenWeb's simple turn path never goes below 4 m
  const MARGIN = 1.0;           // room kept between what sweeps the widest and the field edge, unless `margin` says otherwise
@@ -119,10 +119,18 @@
  }
  // How far a drawbar `len` long from a hitch pin `hitch` behind the pivot folds against the tractor when everything runs
  // round a circle of `radius` at the pivot: the pin is at √(radius² + hitch²) from the centre and the implement's axle,
- // with no side slip, where the drawbar is tangent to its own circle. 180 when it cannot follow.
- function steadyFoldDeg(radius, hitch, len) {
+ // with no side slip, where the drawbar is tangent to its own circle. 180 when it cannot follow. `swingDeg`: a
+ // centre-pivot implement (a mower) swung that much against its drawbar, outwards: its axle runs on a wider circle,
+ // ra = len sin s + √(rh² − len² cos² s) (the drawbar meets the axle's radius at 90° − s), and the drawbar folds less.
+ function steadyAxleRadius(radius, hitch, len, swingDeg) {
+  const rh = Math.hypot(radius, hitch), s = rad(swingDeg || 0), d = rh * rh - Math.pow(len * Math.cos(s), 2);
+  return d < 0 ? null : len * Math.sin(s) + Math.sqrt(d);
+ }
+ function steadyFoldDeg(radius, hitch, len, swingDeg) {
   const rh = Math.hypot(radius, hitch);
-  return len >= rh ? 180 : deg(Math.atan2(hitch, radius) + Math.asin(len / rh));
+  if (!(swingDeg > 0)) return len >= rh ? 180 : deg(Math.atan2(hitch, radius) + Math.asin(len / rh));
+  const ra = steadyAxleRadius(radius, hitch, len, swingDeg), x = ra === null ? 2 : ra * Math.cos(rad(swingDeg)) / rh;
+  return x > 1 ? 180 : deg(Math.atan2(hitch, radius)) + 90 - deg(Math.asin(x));
  }
 
  // ---- the whole turn step by step: the pivot's position and heading every 0.1 m, then where the implement goes ----
@@ -171,12 +179,16 @@
  // when negative; null: not followed; `bodyHalf`: half its width, so its two corners `bodyLeft` and `bodyRight` are
  // followed too). `imp`: rigid {along: + ahead of the pivot, − behind} or trailed {hitch: behind the pivot, bars: [tank
  // hitch,] drawbar, pivotToTool}; offset (right +), half (the width ÷ 2). A trailed implement's axle follows its hitch
- // with no side slip: its heading turns by the hitch's sideways move ÷ the drawbar, forwards and backing up. `foldDeg`:
- // the most a drawbar folds against what pulls it; `firstFoldDeg`: the first one against the machine.
+ // with no side slip: its heading turns by the hitch's sideways move ÷ the drawbar, forwards and backing up. `swing`
+ // (radians): a centre-pivot implement on one drawbar swung against it as far as the drawbar folds, up to that much, so
+ // its axle heads that much wider than the drawbar (the drawbar's heading then turns by the move across the axle's heading
+ // ÷ (drawbar × cos swing)); back in line on a straight. `foldDeg`: the most a drawbar folds against what pulls it;
+ // `firstFoldDeg`: the first one against the machine.
  function sweep(poses, imp) {
   const u = h => ({e: Math.sin(h), n: Math.cos(h)}), rt = h => ({e: Math.cos(h), n: -Math.sin(h)});
   const left = [], right = [], centre = [], heading = [], body = [], bodyLeft = [], bodyRight = [];
   const bars = imp.bars || [], phis = bars.map(() => poses[0].h), prev = bars.map(() => null), bh = imp.bodyHalf || 0;
+  const swing = bars.length === 1 && imp.swing > 0 ? imp.swing : 0;
   let fold = 0, firstFold = 0;
   for (const p of poses) {
    const f = u(p.h);
@@ -187,16 +199,17 @@
    let c, th;
    if (!bars.length) { c = {e: p.e + imp.along * f.e, n: p.n + imp.along * f.n}; th = p.h; }
    else {
-    let pt = {e: p.e - imp.hitch * f.e, n: p.n - imp.hitch * f.n}, pull = p.h;
+    let pt = {e: p.e - imp.hitch * f.e, n: p.n - imp.hitch * f.n}, pull = p.h, sw = 0;
     bars.forEach((bar, j) => {
-     if (prev[j]) { const r = rt(phis[j]); phis[j] += ((pt.e - prev[j].e) * r.e + (pt.n - prev[j].n) * r.n) / bar; }
+     sw = swing ? Math.max(-swing, Math.min(swing, wrap(phis[j] - pull))) : 0;
+     if (prev[j]) { const r = rt(phis[j] + sw); phis[j] += ((pt.e - prev[j].e) * r.e + (pt.n - prev[j].n) * r.n) / (bar * Math.cos(sw)); }
      prev[j] = pt;
      fold = Math.max(fold, Math.abs(wrap(phis[j] - pull)));
      if (j === 0) firstFold = Math.max(firstFold, Math.abs(wrap(phis[j] - pull)));
      pull = phis[j];
      const b = u(phis[j]); pt = {e: pt.e - bar * b.e, n: pt.n - bar * b.n};
     });
-    th = phis[phis.length - 1];
+    th = phis[phis.length - 1] + sw;   // the implement's own heading: its drawbar's, plus the swing
     const b = u(th); c = {e: pt.e - imp.pivotToTool * b.e, n: pt.n - imp.pivotToTool * b.n};
    }
    const r = rt(th);
@@ -223,7 +236,8 @@
  // rear wheel's height), drawbarHeight (the hitch pin above the ground: the tyre is shorter there than at the axle; 0 = the
  // whole wheel counts), drawbarWidth (a trailed implement's drawbar near the hitch, where it can reach those tyres),
  // swingDeg (the most the drawbar may turn to each side against the machine: a semi-mounted pivot's stop, or what the
- // farmer knows it takes; 0 = only the tyres limit it), foldClearanceDeg (how far short of that the turn keeps the drawbar:
+ // farmer knows it takes; 0 = only the tyres limit it), turnSwingDeg (a centre-pivot implement, a mower, swung against its
+ // drawbar in the turn so the drawbar folds less: how far; 0 = held), foldClearanceDeg (how far short of that the turn keeps the drawbar:
  // 5° by default), margin (the room kept between what sweeps the widest in the turn and the field edge: 1 m by default,
  // more where the edge is irregular). `pick`: the key of the turn option the rows describe (the one with the smallest
  // headland when missing or unknown). Returns the numbers, `options` (every turn AgOpenWeb can make here, the smallest
@@ -231,7 +245,7 @@
  function suggest(input, pick) {
   const i = Object.assign({machine: "tractor", wheelbase: 2.5, maxSteerDeg: 35, overhang: 1.2, mount: "rear", width: 6, sections: 0, sectionWidth: 0,
    overlap: 0, offset: 0, axleToTool: 1.8, hitchLength: 1.0, tankHitch: 3.0, drawbar: 3.0, pivotToTool: 0, length: 0, sprayerWidth: 0, margin: MARGIN,
-   trackWidth: 0, tyreWidth: 0.6, wheelDiameter: 1.8, drawbarHeight: 0, drawbarWidth: 0.3, swingDeg: 0, foldClearanceDeg: FOLD_CLEARANCE_DEG}, input);
+   trackWidth: 0, tyreWidth: 0.6, wheelDiameter: 1.8, drawbarHeight: 0, drawbarWidth: 0.3, swingDeg: 0, turnSwingDeg: 0, foldClearanceDeg: FOLD_CLEARANCE_DEG}, input);
   if (i.frontOverhang !== undefined && input.overhang === undefined) i.overhang = i.frontOverhang;
   if (i.sections > 0 && i.sectionWidth > 0 && !(input.width > 0)) i.width = i.sections * i.sectionWidth / 100;
   const trailed = i.mount === "trailed" || i.mount === "tbt", tbt = i.mount === "tbt", front = i.mount === "front", problems = [];
@@ -251,6 +265,8 @@
    problems.push("The rear wheels need a height, the drawbar must pass between the tyres, and its height cannot be negative.");
   if (trailed && !(i.swingDeg >= 0 && i.swingDeg <= 180)) problems.push("The most the drawbar may turn must be between 0 (the tyres only) and 180°.");
   if (trailed && !(i.foldClearanceDeg >= 0 && i.foldClearanceDeg <= 45)) problems.push("The room kept before the drawbar touches must be between 0 and 45°.");
+  if (trailed && !(i.turnSwingDeg >= 0 && i.turnSwingDeg <= 60)) problems.push("The swing in the turn must be between 0 (held) and 60°.");
+  const turnSwing = trailed && !tbt ? i.turnSwingDeg : 0;   // a TBT's tank and implement are not swung
   if (problems.length) return {problems, rows: [], options: []};
   // the working line from the pivot axle, along the machine. A rigid implement is measured from the axle nearest to it; the
   // pivot is a tractor's rear axle and a harvester's front axle, so a front implement on a tractor (or a rear one on a
@@ -283,9 +299,9 @@
   const clearance = i.foldClearanceDeg, foldLimit = limit ? limit.at - clearance : null;
   if (limit) {
    let r = radius;
-   while (steadyFoldDeg(r, i.hitchLength, firstBar) > foldLimit && r < 200) r += 0.1;
+   while (steadyFoldDeg(r, i.hitchLength, firstBar, turnSwing) > foldLimit && r < 200) r += 0.1;
    if (r >= 200) problems.push("The drawbar " + limit.what + " almost straight behind the tractor (at " + limit.at + "°): check the hitch, the drawbar, the track and the swing.");
-   else if (r > radius + 1e-9) { radius = r; why.push("the drawbar " + limit.what + " when it folds " + limit.at + "°: kept under " + foldLimit + "° on the turn's circle, at least " + r1(up(r, 0.1)) + " m"); }
+   else if (r > radius + 1e-9) { radius = r; why.push("the drawbar " + limit.what + " when it folds " + limit.at + "°: kept under " + foldLimit + "° on the turn's circle" + (turnSwing > 0 ? " with the implement swung " + turnSwing + "° against it" : "") + ", at least " + r1(up(r, 0.1)) + " m"); }
   }
   if (problems.length) return {problems, rows: [], options: []};
   radius = up(radius, 0.1);
@@ -323,8 +339,10 @@
    toolWhy = "the " + (front ? "front " : "") + "implement's outer " + (corner > line ? "rear corner" : "end") + " " + r1(toolReach) + " m (√((" + r1(radius) + " + " + r1(halfOut) + ")² + " + r1(along) + "²) − " + r1(radius) + ": " + outName + ", " + alongName + ")";
   } else {
    // a trailed implement cuts inside: its axle runs on a smaller circle than the hitch pin (and a TBT's tank between them)
+   // (a swung centre-pivot implement: on a wider one)
    let r = Math.sqrt(radius * radius + i.hitchLength * i.hitchLength);
-   for (const bar of tbt ? [i.tankHitch, i.drawbar] : [i.drawbar]) { if (bar >= r) { follows = false; r = 0; break; } r = Math.sqrt(r * r - bar * bar); }
+   if (turnSwing > 0) { r = steadyAxleRadius(radius, i.hitchLength, i.drawbar, turnSwing); if (r === null) { follows = false; r = 0; } }
+   else for (const bar of tbt ? [i.tankHitch, i.drawbar] : [i.drawbar]) { if (bar >= r) { follows = false; r = 0; break; } r = Math.sqrt(r * r - bar * bar); }
    toolRadius = r;
    const along = Math.max(i.pivotToTool, length);
    toolReach = Math.max(0, Math.sqrt(Math.pow(toolRadius + halfOut, 2) + along * along) - radius);
@@ -339,7 +357,7 @@
   // further than the distance from boundary allows (a K-turn backs the implement up first), and how far back into the field
   // anything not yet straight on a pass reaches: the implement finishing its pass when the turn starts, its ends swinging,
   // a front implement or a trailed one until it is straight on the next pass (within 10 cm and 2°), a K-turn's tail
-  const imp = trailed ? {bars: tbt ? [i.tankHitch, i.drawbar] : [i.drawbar], hitch: i.hitchLength, pivotToTool: i.pivotToTool, offset: i.offset, half: i.width / 2}
+  const imp = trailed ? {bars: tbt ? [i.tankHitch, i.drawbar] : [i.drawbar], hitch: i.hitchLength, pivotToTool: i.pivotToTool, offset: i.offset, half: i.width / 2, swing: rad(turnSwing)}
    : {along: front ? axleToTool : -axleToTool, offset: i.offset, half: i.width / 2};
   imp.body = articulated ? null : harvester ? -(i.wheelbase + i.overhang) : i.wheelbase + i.overhang;
   imp.bodyHalf = bodyHalf;
@@ -446,6 +464,7 @@
      + i.tyreWidth + " m wide, " + i.trackWidth + " m apart" + (touchDeg === null ? ", never meet" : ", meet when the drawbar folds " + touchDeg + "° against the tractor"));
    }
    if (stopDeg !== null) { value.push("at most " + stopDeg + "°"); parts.push("the drawbar may turn " + stopDeg + "° to each side at most (its stop, or what you typed)"); }
+   if (turnSwing > 0) { value.push("swung " + turnSwing + "° in the turn"); parts.push("the implement swung up to " + turnSwing + "° against its drawbar in the turn, as far as the drawbar folds, so its axle runs wider and the drawbar folds less"); }
    rows.push({key: "fold", name: "How far the drawbar may fold (not a setting)", value: value.join(", "),
     why: parts.join("; ") + "; the turns here fold it " + Math.round(most) + "° at most" + (limit ? " (" + clearance + "° or more away)" : "")});
   }
@@ -456,7 +475,7 @@
    options, chosen: o.key, kTurnOut, headlandOf, tram, goAround: {radius: r1(radius), margin: GO_AROUND_MARGIN}, touchDeg, stopDeg, foldLimit, bodyHalf: r2(bodyHalf), tyreBack: r2(tyreBack)};
  }
 
- const api = {suggest, keyholeDepth, keyholePath, sagittaPath, kTurnBack, kTurnDepth, turnPath, sweep, depthOf, drawbarTouchDeg, steadyFoldDeg, tyreReach,
+ const api = {suggest, keyholeDepth, keyholePath, sagittaPath, kTurnBack, kTurnDepth, turnPath, sweep, depthOf, drawbarTouchDeg, steadyFoldDeg, steadyAxleRadius, tyreReach,
   VERSION, RADIUS_FACTOR, RADIUS_FLOOR, MARGIN, MAX_HITCH_DEG, FOLD_CLEARANCE_DEG, K_TURN_ARC};
  if (typeof module !== "undefined" && module.exports) module.exports = api; else root.AowSettings = api;
 })(typeof window !== "undefined" ? window : globalThis);
diff --git a/Firmware/simulator/aow-settings/test.js b/Firmware/simulator/aow-settings/test.js
index d15d01c..fe69ec0 100644
--- a/Firmware/simulator/aow-settings/test.js
+++ b/Firmware/simulator/aow-settings/test.js
@@ -299,6 +299,35 @@ const tractor = {machine: "tractor", wheelbase: 2.7, maxSteerDeg: 40, overhang:
  eq("own spreader on the Farmall radius", of.radius, 4.8);
  eq("own spreader on the Farmall turn", row(of, "style").value, "Sagitta, skip 0");
  eq("own spreader on the Farmall headland", row(of, "headland").value, "30 m (3 passes)");
+ // Renato's centre-pivot mower conditioner on the Farmall's lower links, measured 13 Nov 2026: its swivel 0.5 m behind the
+ // rear axle, inside the tyres' back edge, so the 6.5 m tongue touches one at 54.5°. Held straight it needs 9.1 m to keep
+ // the tongue under 49.5°; swung 20° against the tongue in the turn, its axle runs wider, the tongue folds less, and the
+ // tongue ÷ sin 75° (6.73 m) sets the radius
+ const mower = {mount: "trailed", width: 3.2, overlap: 0.1, offset: 0, hitchLength: 0.5, drawbar: 6.5, pivotToTool: -2, length: 0, drawbarWidth: 0.3};
+ const held = S.suggest(Object.assign({}, mower, farmall));
+ eq("mower held: touches the tyre", held.touchDeg, 54.5);
+ eq("mower held: radius", held.radius, 9.1);
+ eq("mower held: headland", row(held, "headland").value, "27.9 m (9 passes)");
+ const mw = S.suggest(Object.assign({turnSwingDeg: 20}, mower, farmall));
+ eq("mower problems", mw.problems.length, 0);
+ eq("mower spacing", mw.spacing, 3.1);                 // 10 cm of overlap
+ eq("mower radius", mw.radius, 6.8);
+ eq("mower turn", row(mw, "style").value, "Sagitta, skip 4");
+ eq("mower headland", row(mw, "headland").value, "18.6 m (6 passes)");
+ eq("mower distance", row(mw, "distance").value, "2.8 m");
+ eq("mower fold row", row(mw, "fold").value, "touches the tyres at 54.5°, swung 20° in the turn");
+ if (!(Math.max(...mw.options.map(o => o.sweep.firstFoldDeg)) <= 49.5)) fail.push("mower: every turn should keep the swung tongue under 49.5°");
+ eq("swing out of range", S.suggest(Object.assign({turnSwingDeg: 70}, mower, farmall)).problems.length, 1);
+ // the swung implement followed step by step round a circle settles where the formula says
+ {
+  const R = 6.8, poses = [];
+  for (let k = 0; k <= Math.round(3 * 2 * Math.PI * R / 0.05); k++) { const t = k * 0.05 / R; poses.push({e: R - R * Math.cos(t), n: R * Math.sin(t), h: t}); }
+  for (const sw of [0, 10, 20]) {
+   const f = S.sweep(poses, {bars: [6.5], hitch: 0.5, pivotToTool: 0, offset: 0, half: 1.6, swing: sw * Math.PI / 180}).firstFoldDeg;
+   if (Math.abs(f - S.steadyFoldDeg(R, 0.5, 6.5, sw)) > 0.5) fail.push("swing " + sw + "°: the path folds " + f.toFixed(1) + "°, the formula " + S.steadyFoldDeg(R, 0.5, 6.5, sw).toFixed(1) + "°");
+  }
+  eq("swing 0 is the held formula", S.steadyFoldDeg(9.1, 0.5, 6.5, 0), S.steadyFoldDeg(9.1, 0.5, 6.5));
+ }
  // the tractor's width: its nose's outer corner, (1.81 + 0.65) ÷ 2 = 1.23 m off the centre line, sweeps 2.6 m past the pivot's path, not 1.7
  eq("tractor half width", m.bodyHalf, 1.23);
  eq("nose corner reach", m.noseReach, 2.3);   // √((6.7 + 1.23)² + 4.2²) − 6.7
diff --git a/Firmware/simulator/smoke-test.js b/Firmware/simulator/smoke-test.js
index 4796997..e39bc86 100644
--- a/Firmware/simulator/smoke-test.js
+++ b/Firmware/simulator/smoke-test.js
@@ -228,8 +228,24 @@ async function teensy(browser, port, q, name) {
   await pg.click("button:has-text('Case IH Maxxum 135')"); await pg.waitForTimeout(300);
   if ((await pg.inputValue("#hitch")) !== "0.7") fail.push(what + ": the Maxxum button should put the spreader back on its 0.7 m pin");
   await expect(pg, what, "#results tbody tr[data-key=radius] td.v", /^5\.4 m$/);
+  // Renato's centre-pivot mower conditioner comes with the Farmall, on its lower links, swung in the turn; then back to the Maxxum
+  await pg.click("button:has-text('3.2 m centre-pivot mower conditioner')"); await pg.waitForTimeout(300);
+  await expect(pg, what, "#implements button.on", /^3\.2 m centre-pivot mower conditioner$/);
+  await expect(pg, what, "#tractors button.on", /^Case IH Farmall 115C$/);
+  await expect(pg, what, "#presetNote", /^Renato's centre-pivot mower conditioner, used with the Farmall/);
+  if ((await pg.inputValue("#wheelbase")) !== "2.3" || (await pg.inputValue("#hitch")) !== "0.5" || (await pg.inputValue("#width")) !== "3.2" || (await pg.inputValue("#turnSwingDeg")) !== "20") fail.push(what + ": the mower button should press the Farmall, put the mower's swivel 0.5 m behind its rear axle and swing it 20° in the turn");
+  await expect(pg, what, "#results tbody tr[data-key=radius] td.v", /^6\.8 m$/);     // swung, its 6.5 m tongue ÷ sin 75°
+  await expect(pg, what, "#results tbody tr[data-key=style] td.v", /^Sagitta, skip 4$/);
+  await expect(pg, what, "#results tbody tr[data-key=headland] td.v", /^18\.6 m \(6 passes\)$/);
+  await expect(pg, what, "#results tbody tr[data-key=fold] td.v", /^touches the tyres at 54\.5°, swung 20° in the turn$/);
+  await shot(pg, "aow-settings-mower");
+  await pg.fill("#turnSwingDeg", "0"); await pg.waitForTimeout(300);
+  await expect(pg, what, "#results tbody tr[data-key=radius] td.v", /^9\.1 m$/);     // held straight, the tongue touches a tyre at 54.5°
+  await pg.click("button:has-text('Case IH Maxxum 135')"); await pg.waitForTimeout(300);
+  if ((await pg.inputValue("#hitch")) !== "0.5") fail.push(what + ": the mower is on the lower links: another tractor should keep its 0.5 m swivel");
   await pg.click("button:has-text('4 m disc harrow')"); await pg.waitForTimeout(300);
   await expect(pg, what, "#results tbody tr[data-key=style] td.v", /^Sagitta, skip 2$/);
+  if ((await pg.inputValue("#turnSwingDeg")) !== "0") fail.push(what + ": only the centre-pivot mower is swung in the turn");
   await pg.click("button:has-text('4-furrow reversible plough')"); await pg.waitForTimeout(300);
   if (await pg.locator("#drawbarHeight").isVisible()) fail.push(what + ": the drawbar height is for trailed implements only");
   if (!(await pg.locator("#trackWidth").isVisible())) fail.push(what + ": the rear track gives the tractor's width for every implement");