schema_version: 1 name: bearing-housing intent: >- Cast oval flanged bearing housing (the housing alone, no bearing or screws), one connected solid in millimetres. Flange = convex hull of a D57 circle at the origin and two D22 lobes at (+-38.25, 0), 11 thick; D57 boss to z = 26; every side face drafted inward 4 deg about the neutral plane z = 0; every edge of the drafted body rounded r = 1 before any hole is cut; D47 x 14 counterbore from the boss top over a D14 through bore; two D10 through mounting holes at (+-38.25, 0). The authoritative source is sources/bearing-housing-spec.md (parameters, construction and reference measurements); the three renders are illustrative. units: length: mm angle: deg material: null density_kg_m3: null process: "casting (drafted 4 deg, r = 1 edge rounds), machined bores" release_status: reconstruction frame: origin: "centre of the flat flange bottom face, on the bore axis: (0, 0) in plan at z = 0" axes: x: "along the flange length through both mounting holes (holes at x = +-38.25, y = 0)" y: "across the flange, perpendicular to the mounting-hole line in the bottom plane" z: "up the bore axis, out of the bore, from the flange bottom (z = 0) to the boss top (z = 26)" datums: - name: A description: "flat bottom face of the flange, plane z = 0 (the part sits on it; all material at z >= 0)" - name: B description: "bore axis: the z axis through the origin" - name: C description: "mirror planes x = 0 and y = 0 (mounting holes symmetric on the x axis)" envelope: min: [-49.1775, -28.4275, 0] max: [49.1775, 28.4275, 26] tolerance: 0.05 parameters: - name: overallHeight value: 26 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, A" tolerance: 0.01 description: "flange bottom to boss top" - name: flangeThickness value: 11 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, A1" tolerance: 0.01 description: "flange extrusion height z 0 .. 11" - name: bossDiameter value: 57 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, Db2" tolerance: 0.01 description: "boss and flange-centre circle diameter at z = 0 (true size at the neutral plane)" - name: flangeLength value: 98.5 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, H" tolerance: 0.01 description: "flange length over the lobes at z = 0, before the edge round" - name: holeSpacing value: 76.5 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, J" tolerance: 0.01 description: "mounting-hole (and lobe-centre) spacing; holes at x = +-holeSpacing/2, y = 0" - name: lobeDiameter value: 22 unit: mm provenance: derived formula: "flangeLength - holeSpacing" tolerance: 0.01 description: "lobe diameter at z = 0; lobe centres = hole centres" - name: draftAngle value: 4 unit: deg provenance: stated source: "bearing-housing-spec.md, Parameters, draft angle; Construction step 3" tolerance: 0.01 description: "inward taper of every side face going up, about the neutral plane z = 0" - name: edgeRadius value: 1 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, edge round radius; Construction step 4" tolerance: 0.01 description: "round on every edge of the drafted body, applied before any hole is cut" - name: counterboreDiameter value: 47 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, counterbore diameter" tolerance: 0.01 description: "bearing seat diameter" - name: counterboreDepth value: 14 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, counterbore depth (floor at z = 12)" tolerance: 0.01 description: "counterbore depth from the boss top" - name: boreDiameter value: 14 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, through-bore diameter" tolerance: 0.01 description: "through bore from the counterbore floor (z = 12) to the bottom face" edit_test: delta: 1 expect: volume_delta: -273.32 direction: decrease bbox_delta: [0, 0, 0] tolerance_rel: 0.02 - name: mountingHoleDiameter value: 10 unit: mm provenance: stated source: "bearing-housing-spec.md, Parameters, mounting-hole diameter" tolerance: 0.01 description: "two through holes in the flange at (+-holeSpacing/2, 0)" edit_test: delta: 1 expect: volume_delta: -362.85 direction: decrease bbox_delta: [0, 0, 0] tolerance_rel: 0.02 features: - id: flange kind: extrude description: "convex hull of the D57 centre circle and two D22 lobes at (+-38.25, 0), tangent lines between them, extruded z 0 .. 11" parameters: [bossDiameter, flangeLength, holeSpacing, lobeDiameter, flangeThickness] verify: - method: bbox - method: section section: section_flange_z5p5 - method: face face: bottom_face - method: face face: flange_top_left - method: face face: flange_top_right - method: solid points: [[46, 0, 5.5], [-46, 0, 5.5]] - id: boss kind: boss description: "D57 circle at z = 0 extruded to z = 26, united with the flange" parameters: [bossDiameter, overallHeight] verify: - method: section section: section_boss_z15 - method: face face: boss_top - method: solid points: [[0, 25.3, 20], [0, -25.3, 20]] - method: void points: [[36, 0, 13], [-36, 0, 13]] note: "air above the flange top beside the boss" - id: draft kind: other description: "every side face of the flange + boss union tapers inward 4 deg going up about z = 0 (lobes D20.46 and boss D55.46 at z = 11, boss D53.36 at z = 26); horizontal faces stay horizontal" parameters: [draftAngle] verify: - method: plane plane: draft_flat_pp - method: plane plane: draft_flat_mp - method: plane plane: draft_flat_mm - method: plane plane: draft_flat_pm - method: section section: section_boss_z24 note: "boss annulus shrinks from z = 15 to z = 24 by the draft" - id: edgeRounds kind: fillet description: "r = 1 round on every edge of the drafted body (outer bottom edge, flange-top outer edge, concave flange-to-boss edge, boss-top outer edge), before any hole is cut" parameters: [edgeRadius] verify: - method: bbox note: "the bottom round pulls the extremes in from 98.5 x 57 to 98.355 x 56.855" - method: face face: bottom_face - id: counterbore kind: pocket description: "D47 x 14 counterbore from the boss top, floor at z = 12, sharp edges" parameters: [counterboreDiameter, counterboreDepth, overallHeight] verify: - method: cylinder cylinder: counterbore - method: face face: counterbore_floor - method: void points: [[0, 0, 19], [15, 0, 19]] - method: solid points: [[15, 0, 6], [0, -15, 6]] note: "material under the counterbore floor" - id: throughBore kind: hole description: "D14 bore from the counterbore floor (z = 12) through to the bottom face" parameters: [boreDiameter] verify: - method: cylinder cylinder: through_bore - method: void points: [[0, 0, 6]] - id: mountingHoles kind: hole description: "two D10 through holes in the flange at (+-38.25, 0), z 0 .. 11, sharp edges" parameters: [mountingHoleDiameter, holeSpacing] count: 2 verify: - method: cylinder cylinder: mounting_hole_left - method: cylinder cylinder: mounting_hole_right - method: void points: [[38.25, 0, 5.5], [-38.25, 0, 5.5]] - method: count section: section_y0 count: 4 interfaces: - name: bearingSeat description: "the D47 x 14 counterbore and the boss top that seat the bearing; neither hole edit moves them" must_not_change: true checks: [counterbore, boss_top, section_boss_z15, section_boss_z24] - name: castOutline description: "the drafted outline and overall envelope; fixed in this case (no outline edits), unmoved by the hole edits" must_not_change: true checks: [draft_flat_pp, draft_flat_mp, draft_flat_mm, draft_flat_pm, spanX, spanY, spanZ, mirrorX, mirrorY] acceptance: bbox_tolerance: 0.05 solid_count: 1 volume: expected: 46881.3 tolerance_rel: 0.005 provenance: measured (reference model) note: "spec reference measurement; cross-check: drafted hull + boss without rounds 74850 minus counterbore pi*23.5^2*14, bore pi*7^2*12 and two holes 2*pi*5^2*11 = 46986; the r = 1 rounds remove the remaining ~105" sections: - id: section_flange_z5p5 plane: z at: 5.5 expect: area: 3321.8 area_tolerance_rel: 0.01 loops: 1 holes: 3 description: "flange mid-thickness: one outline with the bore and both mounting holes" - id: section_boss_z15 plane: z at: 15 expect: area: 632.4 area_tolerance_rel: 0.01 loops: 1 holes: 1 description: "boss annulus between the drafted boss and the counterbore" - id: section_boss_z24 plane: z at: 24 expect: area: 525.1 area_tolerance_rel: 0.01 loops: 1 holes: 1 description: "boss annulus near the top, smaller than at z = 15 by the draft" - id: section_y0 plane: y at: 0 expect: area: 844.4 area_tolerance_rel: 0.01 loops: 4 holes: 0 description: "section through the hole line: two lobe ends and the two halves either side of the bore" faces: - name: bottom_face plane: z at: 0 normal: "-" area: 3161.0 area_tolerance_rel: 0.02 center: [0, 0] mode: one - name: counterbore_floor plane: z at: 12 normal: "+" area: 1581.0 area_tolerance_rel: 0.001 tolerance: 0.01 center: [0, 0] mode: one - name: flange_top_left plane: z at: 11 normal: "+" area: 369.2 area_tolerance_rel: 0.02 center: [-34.38, 0] mode: one - name: flange_top_right plane: z at: 11 normal: "+" area: 369.2 area_tolerance_rel: 0.02 center: [34.38, 0] mode: one - name: boss_top plane: z at: 26 normal: "+" area: 348.0 area_tolerance_rel: 0.02 center: [0, 0] mode: one cylinders: - name: counterbore point: [0, 0, 12] direction: [0, 0, 1] kind: hole diameter: 47 radius_tolerance: 0.02 length: 14 length_tolerance: 0.05 t_range: [0, 14] description: "D47 counterbore, z 12 .. 26" - name: through_bore point: [0, 0, 0] direction: [0, 0, 1] kind: hole diameter: 14 radius_tolerance: 0.02 length: 12 length_tolerance: 0.05 t_range: [0, 12] description: "D14 through bore, z 0 .. 12" - name: mounting_hole_left point: [-38.25, 0, 0] direction: [0, 0, 1] kind: hole diameter: 10 radius_tolerance: 0.02 length: 11 length_tolerance: 0.05 t_range: [0, 11] description: "D10 mounting hole at x = -38.25, z 0 .. 11" - name: mounting_hole_right point: [38.25, 0, 0] direction: [0, 0, 1] kind: hole diameter: 10 radius_tolerance: 0.02 length: 11 length_tolerance: 0.05 t_range: [0, 11] description: "D10 mounting hole at x = +38.25, z 0 .. 11" planes: - name: draft_flat_pp point: [27.79, 17.31, 5.64] normal: [0.4564, 0.8870, 0.0698] area: 311.4 area_tolerance_rel: 0.03 angle_tolerance_deg: 0.5 description: "drafted tangent flat, +x +y quadrant" - name: draft_flat_mp point: [-27.79, 17.31, 5.64] normal: [-0.4564, 0.8870, 0.0698] area: 311.4 area_tolerance_rel: 0.03 angle_tolerance_deg: 0.5 description: "drafted tangent flat, -x +y quadrant" - name: draft_flat_mm point: [-27.79, -17.31, 5.64] normal: [-0.4564, -0.8870, 0.0698] area: 311.4 area_tolerance_rel: 0.03 angle_tolerance_deg: 0.5 description: "drafted tangent flat, -x -y quadrant" - name: draft_flat_pm point: [27.79, -17.31, 5.64] normal: [0.4564, -0.8870, 0.0698] area: 311.4 area_tolerance_rel: 0.03 angle_tolerance_deg: 0.5 description: "drafted tangent flat, +x -y quadrant" dimensions: - name: spanX axis: x expected: 98.355 tolerance: 0.05 description: "bbox length over the rounded lobes" - name: spanY axis: y expected: 56.855 tolerance: 0.05 description: "bbox width over the rounded boss/flange centre" - name: spanZ axis: z expected: 26 tolerance: 0.05 description: "overall height, flange bottom to boss top" probes: - name: flangeMaterial state: solid points: [[46, 0, 5.5], [-46, 0, 5.5]] description: "lobe material outboard of the mounting holes" - name: bossWall state: solid points: [[0, 25.3, 20], [0, -25.3, 20]] description: "boss wall between the counterbore (r 23.5) and the drafted outside (r ~27.1)" - name: underFloor state: solid points: [[15, 0, 6], [0, -15, 6]] description: "material under the counterbore floor, outside the bore" - name: inCounterbore state: void points: [[0, 0, 19], [15, 0, 19]] - name: inBore state: void points: [[0, 0, 6]] - name: inMountingHoles state: void points: [[38.25, 0, 5.5], [-38.25, 0, 5.5]] - name: airBesideBoss state: void points: [[36, 0, 13], [-36, 0, 13]] description: "air above the flange tops beside the boss" cylinder_counts: - name: mountingHoles diameter: 10 radius_tolerance: 0.02 kind: hole direction: [0, 0, 1] expected: 2 symmetry: - name: mirrorX plane: x at: 0 max_deviation: 0.1 p95_deviation: 0.05 - name: mirrorY plane: y at: 0 max_deviation: 0.1 p95_deviation: 0.05 blockout: volume_min: 72000 volume_max: 80000 references: - path: sources/bearing-housing-spec.md kind: text role: authoritative sha256: d286e12f68d057825869c8474013ffee848b9d5b49efbfd8f86c3b16d65b6d35 units: mm note: "parameters, construction order and reference measurements" - path: sources/bearing-housing-iso.png kind: image role: illustrative sha256: 993e43deea9ec33e0f0ef390d84558e2f93a65aaec1f2ad424b6f8e1bd52a01e note: "isometric render of the reference: oval flange, drafted boss, counterbore, bore, two holes" - path: sources/bearing-housing-top.png kind: image role: illustrative sha256: c47574c5ab70ca03bd936d2a8b9baa37d16ab4634b9972c8823ec3240b08bb38 note: "top view, +x right, +y up: tangent-hull outline, symmetric about x = 0 and y = 0" - path: sources/bearing-housing-section.png kind: image role: illustrative units: mm note: "section y = 0 (x-z plane) with mm axes: four loops, drafted lobe ends and boss walls, floor at z = 12" sha256: fe4ce0ff2989143e3e8525bed3692981ed55f7555f57a5d4c4543b669dd36740 open_questions: - "Surface area and centre of mass are not given by the spec and are not declared (centre of mass is x = y = 0 by symmetry; its z is not computed)." - "Only the hole diameters are edit-tested; the outline parameters (overallHeight, flangeThickness, bossDiameter, flangeLength, holeSpacing, draftAngle, edgeRadius) stay fixed because the drafted, fully rounded tangent hull rebuilds in OpenCascade only at the nominal outline (spec robustness note)."