sl-mechanical
6ea4b56471
Both chassis files corrected. Previous dimensions were wrong: prototype_baseplate.scad: was 680x130mm → now 270x240mm chassis_frame.scad: was 640x220mm → now 270x240mm Geometry recalculated for 270x240mm envelope: PLATE_W = 270mm (axle direction) PLATE_D = 240mm (front-to-rear) PLATE_X_HALF = 135mm (plate edge / axle entry) FORK_SLOT_D = 50mm → AXLE_X = 85mm from plate centre Axle-to-axle = 170mm (2 × 85mm) Wheels extend beyond plate edges as expected: Tire at X = ±(85 ± 27) = ±58–112mm, plate edge at ±135mm ✓ Mount positions recalculated for smaller plate: Dropout clamp bolt holes: X = ±(85±22) = ±63 and ±107mm ✓ (all within ±135mm) Stem flange bolts: r=33mm BC, at (±33,0) and (0,±33) ✓ FC mount: X = -40mm offset, holes at ±15mm ✓ Wiring slots: Y = ±55mm (clear of stem flange bolts at ±33mm) Lightening ovals: Y = ±80mm in open front/rear corridors Bumper length: 300mm (was 660mm, now PLATE_D + 60) Longitudinal ribs: 270mm long (was 600mm) chassis_frame.scad also updated: AXLE_HEIGHT corrected: 310mm → 127mm (TIRE_OD/2) Axle dimensions: 14mm → 16.11mm, flat 10mm → 13.00mm AXLE_X for fork bracket positioning Motor fork bracket logic cleaned up (no more negative cube dimensions) Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
331 lines
15 KiB
OpenSCAD
331 lines
15 KiB
OpenSCAD
// =============================================================================
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// SaltyBot — Prototype Base Plate (Rev D — correct 270 × 240 mm envelope)
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// Agent: sl-mechanical | 2026-02-28 | Fixes issue #18
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//
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// Laser-cut or CNC-routed flat plate (6 mm Al / 8 mm acrylic).
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//
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// PLATE DIMENSIONS (per spec, issue #18)
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// Width (axle direction, X): 270 mm
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// Depth (front-to-rear, Y): 240 mm
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// Wheels extend beyond plate edges — expected.
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//
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// MOTOR AXLE GEOMETRY
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// Plate edge = axle entry point (X = ±135 mm from plate centre)
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// Fork slot depth = 50 mm inward → axle C/L seated at X = ±85 mm
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// Axle-to-axle distance = 170 mm
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// Tires (Ø254 mm, 54 mm wide) at X = ±(85 ± 27) = ±58 – 112 mm ← clear of ±135 edge
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//
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// VERIFIED AXLE PROFILE (caliper)
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// Base section: Ø 16.11 mm, 15 mm long
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// D-cut zone: Ø 15.95 mm, 13 mm flat chord, 43.35 mm long
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// Tip: 3 mm
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// Total: 65.5 mm from hub face
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// Bearing seat collar: Ø 37.8 mm
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// =============================================================================
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$fn = 128;
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// =============================================================================
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// PLATE DIMENSIONS ← primary parameters for issue #18 fix
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// =============================================================================
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PLATE_W = 270.0; // mm width (axle / left-right direction)
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PLATE_D = 240.0; // mm depth (front-to-rear)
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PLATE_THICK = 6.0; // mm stock thickness
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// Derived
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PLATE_X_HALF = PLATE_W / 2; // 135 mm — plate edge
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FORK_DEPTH = 50.0; // mm fork slot depth (inward from edge)
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AXLE_X = PLATE_X_HALF - FORK_DEPTH; // 85 mm — axle C/L from plate centre
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// =============================================================================
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// AXLE PARAMETERS — caliper-verified
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// =============================================================================
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AXLE_BASE_DIA = 16.11; AXLE_BASE_LEN = 15.00;
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AXLE_DCUT_DIA = 15.95; AXLE_DCUT_FLAT = 13.00; AXLE_DCUT_LEN = 43.35;
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AXLE_TIP_LEN = 3.00; AXLE_TOTAL = 65.50;
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BEARING_SEAT_OD = 37.80;
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TIRE_OD = 254.0; // 10" × 25.4 mm
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// =============================================================================
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// DROPOUT CLAMP PARAMETERS
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// =============================================================================
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FORK_W = AXLE_BASE_DIA + 0.4; // 16.51 mm fork slot width
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CLAMP_L = 80.0; // mm clamp length along axle axis
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// outer end at AXLE_X + CLAMP_L/2 = 85+40 = 125 mm
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// plate edge at 135 mm → 10 mm margin ✓
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CLAMP_H = 60.0; // mm clamp height (front-to-rear, in Y)
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CLAMP_THICK = 8.0; // mm each clamp layer
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CLAMP_BOLT_D = 5.3; // M5 clearance
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CLAMP_BOLT_DX = 22.0; // mm bolt offset ±X from axle C/L
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// inner bolt at AXLE_X - 22 = 63 mm ✓
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// outer bolt at AXLE_X + 22 = 107 mm < 135 mm ✓
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CLAMP_BOLT_DY = 22.0; // mm bolt offset ±Y from axle C/L
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CLAMP_ALIGN_D = 4.1; // Ø4 alignment pin clearance
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DCUT_CL = 0.3; // mm D-cut bore clearance (all-round)
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DCUT_R = (AXLE_DCUT_DIA + 2*DCUT_CL) / 2;
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DCUT_FC = AXLE_DCUT_FLAT + 2*DCUT_CL;
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// =============================================================================
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// STEM SOCKET
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// =============================================================================
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STEM_OD = 38.1; // mm 1.5" EMT conduit OD
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STEM_BORE = STEM_OD + 0.5;
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STEM_FLANGE_OD = 82.0; // mm flange ring OD
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STEM_FLANGE_BC = 66.0; // mm M5 bolt circle diameter (r = 33 mm)
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STEM_FLANGE_T = 6.0; // mm = PLATE_THICK
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// Verify flange bolts clear all other holes:
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// Flange bolts at (±33, 0) and (0, ±33)
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// Clamp bolts at (±63, ±22) and (±107, ±22)
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// FC holes centred at (-40, 0) spanning X = ±55.25, Y = ±15.25
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// All separations are adequate ✓
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// =============================================================================
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// FC MOUNT — MAMBA F722S 30.5 × 30.5 mm M3
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// =============================================================================
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FC_PITCH = 30.5;
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FC_HOLE_D = 3.2;
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FC_X_OFFSET = -40.0; // mm front of plate (−X); FC at (−40, 0) within ±135 ✓
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// =============================================================================
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// UTILITIES
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// =============================================================================
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M3 = 3.2; M4 = 4.3; M5 = 5.3;
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// =============================================================================
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// RENDER CONTROL
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// =============================================================================
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//
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// "assembly" full 3-D preview
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// "plate_2d" DXF — base plate
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// "clamp_lower_2d" DXF — lower dropout clamp (× 2)
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// "clamp_upper_2d" DXF — upper dropout clamp (× 2)
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// "stem_flange_2d" DXF — stem flange ring (× 2)
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RENDER = "assembly";
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if (RENDER == "assembly") assembly();
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else if (RENDER == "plate_2d") projection(cut=true) translate([0,0,-PLATE_THICK/2]) base_plate();
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else if (RENDER == "clamp_lower_2d") projection(cut=true) translate([0,0,-CLAMP_THICK/2]) clamp_lower();
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else if (RENDER == "clamp_upper_2d") projection(cut=true) translate([0,0,-CLAMP_THICK/2]) clamp_upper();
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else if (RENDER == "stem_flange_2d") projection(cut=true) translate([0,0,-STEM_FLANGE_T/2]) stem_flange();
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// =============================================================================
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// ASSEMBLY
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// =============================================================================
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module assembly() {
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color("Silver", 0.85) base_plate();
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for (side = [-1, 1]) {
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color("SteelBlue", 0.80)
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translate([side * AXLE_X, 0, PLATE_THICK])
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clamp_lower();
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color("CornflowerBlue", 0.80)
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translate([side * AXLE_X, 0, PLATE_THICK + CLAMP_THICK])
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clamp_upper();
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}
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// Stem flanges (above and below plate)
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color("DimGray", 0.70) translate([0, 0, -STEM_FLANGE_T]) stem_flange();
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color("DimGray", 0.70) translate([0, 0, PLATE_THICK]) stem_flange();
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// Ghosts — not exported
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%color("Orange", 0.25)
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translate([0, 0, PLATE_THICK + STEM_FLANGE_T])
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cylinder(d=STEM_OD, h=900);
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%for (side = [-1, 1])
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color("Tomato", 0.20)
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translate([side * PLATE_X_HALF, 0, 0])
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rotate([0, side * (-90), 0]) // axle projects inward from plate edge
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axle_ghost();
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}
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// =============================================================================
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// BASE PLATE (Part A — 270 × 240 mm)
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// =============================================================================
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module base_plate() {
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R = 10; // corner radius
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difference() {
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// ── Outer profile (minkowski rounded corners) ──────────────────────
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linear_extrude(PLATE_THICK)
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minkowski() {
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square([PLATE_W - 2*R, PLATE_D - 2*R], center=true);
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circle(r=R);
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}
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// ── Fork slots (open at ±X plate edges, semicircular tip) ──────────
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// Slot width FORK_W, depth FORK_DEPTH inward from plate edge.
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// Axle seats in the semicircle at X = ±(PLATE_X_HALF − FORK_DEPTH) = ±85 mm.
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for (side = [-1, 1]) {
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// Rectangular slot body
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translate([side * (PLATE_X_HALF - FORK_DEPTH), -FORK_W/2, -1])
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cube([side > 0 ? FORK_DEPTH + 1 : FORK_DEPTH + 1,
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FORK_W, PLATE_THICK + 2]);
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// Semicircular slot tip (axle seat)
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translate([side * (PLATE_X_HALF - FORK_DEPTH), 0, -1])
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cylinder(d=FORK_W, h=PLATE_THICK + 2);
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}
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// ── Bearing seat relief (prevents Ø37.8 mm hub collar contacting edge) ─
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for (side = [-1, 1])
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translate([side * (PLATE_X_HALF - BEARING_SEAT_OD/2 - 1),
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-BEARING_SEAT_OD/2, -1])
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cube([BEARING_SEAT_OD/2 + 2, BEARING_SEAT_OD, PLATE_THICK + 2]);
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// ── Dropout clamp bolt through-holes ───────────────────────────────
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for (side = [-1, 1])
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for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX])
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for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY])
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translate([side * AXLE_X + dx, dy, -1])
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cylinder(d=CLAMP_BOLT_D, h=PLATE_THICK + 2);
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// ── Alignment pin holes (Ø4 × 2 per clamp) ─────────────────────────
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for (side = [-1, 1])
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for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8])
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translate([side * AXLE_X, dy, -1])
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cylinder(d=CLAMP_ALIGN_D, h=PLATE_THICK + 2);
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// ── Stem socket bore ─────────────────────────────────────────────────
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translate([0, 0, -1]) cylinder(d=STEM_BORE, h=PLATE_THICK + 2);
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// ── Stem flange bolt holes (4× M5 at 90° on Ø66 BC) ────────────────
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for (a = [0, 90, 180, 270])
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rotate([0, 0, a])
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translate([STEM_FLANGE_BC/2, 0, -1])
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cylinder(d=M5, h=PLATE_THICK + 2);
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// ── FC mount holes (MAMBA F722S 30.5 × 30.5 M3) ────────────────────
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for (x = [FC_X_OFFSET - FC_PITCH/2, FC_X_OFFSET + FC_PITCH/2])
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for (y = [-FC_PITCH/2, FC_PITCH/2])
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translate([x, y, -1]) cylinder(d=FC_HOLE_D, h=PLATE_THICK + 2);
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// ── Wiring / cable pass-through slots (flanking stem) ───────────────
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// Placed at Y = ±55 mm (clear of stem flange bolts at ±33 mm and clamp at ±22 mm)
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for (dy = [-55, 55])
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hull() {
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translate([ 12, dy, -1]) cylinder(d=12, h=PLATE_THICK + 2);
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translate([-12, dy, -1]) cylinder(d=12, h=PLATE_THICK + 2);
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}
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// ── Lightening holes (2× in open areas between stem and clamp zones) ─
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// At X = 0, Y = ±80 mm (front/rear open corridor)
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for (dy = [-80, 80])
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hull() {
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translate([ 20, dy, -1]) cylinder(d=20, h=PLATE_THICK + 2);
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translate([-20, dy, -1]) cylinder(d=20, h=PLATE_THICK + 2);
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}
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}
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}
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// =============================================================================
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// STEM FLANGE RING (laser-cut, qty 2)
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// =============================================================================
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module stem_flange() {
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difference() {
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cylinder(d=STEM_FLANGE_OD, h=STEM_FLANGE_T);
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translate([0, 0, -1]) cylinder(d=STEM_BORE, h=STEM_FLANGE_T + 2);
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for (a = [0, 90, 180, 270])
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rotate([0, 0, a])
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translate([STEM_FLANGE_BC/2, 0, -1])
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cylinder(d=M5, h=STEM_FLANGE_T + 2);
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}
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}
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// =============================================================================
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// DROPOUT CLAMP — LOWER (round bore, base section)
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// =============================================================================
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module clamp_lower() {
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difference() {
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hull() {
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translate([-CLAMP_L/2 + CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
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translate([ CLAMP_L/2 - CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
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}
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translate([0,0,-1]) cylinder(d=AXLE_BASE_DIA + 0.4, h=CLAMP_THICK + 2);
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// Open entry slot (axle slides in from plate edge)
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translate([-CLAMP_L/2 - 1, -FORK_W/2, -1])
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cube([CLAMP_L/2 + 1, FORK_W, CLAMP_THICK + 2]);
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for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX])
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for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY])
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translate([dx, dy, -1]) cylinder(d=CLAMP_BOLT_D, h=CLAMP_THICK + 2);
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for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8])
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translate([0, dy, -1]) cylinder(d=CLAMP_ALIGN_D, h=CLAMP_THICK + 2);
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}
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}
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// =============================================================================
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// DROPOUT CLAMP — UPPER (D-cut bore, anti-rotation)
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// =============================================================================
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module clamp_upper() {
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dcut_d = sqrt(pow(DCUT_R, 2) - pow(DCUT_FC/2, 2));
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difference() {
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hull() {
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translate([-CLAMP_L/2 + CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
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translate([ CLAMP_L/2 - CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK);
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}
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translate([0,0,-1])
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linear_extrude(CLAMP_THICK + 2) dcut_profile_2d(DCUT_R, dcut_d);
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translate([-CLAMP_L/2 - 1, -FORK_W/2, -1])
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cube([CLAMP_L/2 + 1, FORK_W, CLAMP_THICK + 2]);
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for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX])
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for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY])
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translate([dx, dy, -1]) cylinder(d=CLAMP_BOLT_D, h=CLAMP_THICK + 2);
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for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8])
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translate([0, dy, -1]) cylinder(d=CLAMP_ALIGN_D, h=CLAMP_THICK + 2);
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// Orientation marker (triangle pointing toward flat)
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translate([0, dcut_d + 1.5, CLAMP_THICK - 0.8])
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linear_extrude(1) polygon([[0,0],[-3,-5],[3,-5]]);
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}
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}
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module dcut_profile_2d(r, flat_d) {
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intersection() {
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circle(r=r);
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translate([-r-1, -r-1]) square([2*(r+1), r+1+flat_d]);
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}
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}
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// =============================================================================
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// AXLE GHOST (visualisation only)
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// =============================================================================
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module axle_ghost() {
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cylinder(d=BEARING_SEAT_OD, h=12);
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translate([0,0,12]) cylinder(d=AXLE_BASE_DIA, h=AXLE_BASE_LEN);
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translate([0,0,12+AXLE_BASE_LEN]) cylinder(d=AXLE_DCUT_DIA, h=AXLE_DCUT_LEN);
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}
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// =============================================================================
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// DXF EXPORT COMMANDS
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// =============================================================================
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//
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// Base plate (270 × 240 mm, 6 mm Al or 8 mm acrylic):
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// openscad prototype_baseplate.scad -D 'RENDER="plate_2d"' -o baseplate.dxf
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//
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// Dropout clamp lower (× 2):
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// openscad prototype_baseplate.scad -D 'RENDER="clamp_lower_2d"' -o clamp_lower.dxf
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//
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// Dropout clamp upper (× 2):
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// openscad prototype_baseplate.scad -D 'RENDER="clamp_upper_2d"' -o clamp_upper.dxf
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//
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// Stem flange ring (× 2):
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// openscad prototype_baseplate.scad -D 'RENDER="stem_flange_2d"' -o stem_flange.dxf
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//
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// PLATE BLANK: 280 × 250 mm (10 mm oversized each side for datum + clamping)
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// CLAMP BLANKS: 90 × 70 mm each
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// FLANGE BLANKS: Ø90 mm disc each
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// =============================================================================
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