diff --git a/chassis/BOM.md b/chassis/BOM.md index 56d4588..0a92d8f 100644 --- a/chassis/BOM.md +++ b/chassis/BOM.md @@ -1,24 +1,78 @@ # SaltyBot Chassis — Bill of Materials -**Task:** bd-1iy5 -**Rev:** A — 2026-02-28 +**Task:** bd-1iy5 / prototype-baseplate +**Rev:** C — 2026-02-28 (vertical stem architecture; batteries on mast carousel) **Agent:** sl-mechanical --- +## ⚠ Axle Measurement Update (Rev B) + +PR #7 (`chassis_frame.scad`) used placeholder values. The table below records the +**caliper-verified** hub motor axle dimensions. All new designs must use these. + +| Feature | Measured | PR #7 placeholder | Delta | +|---------|----------|-------------------|-------| +| Axle base diameter (round, near hub) | **16.11 mm** | 14 mm | +2.11 mm | +| D-cut shaft OD | **15.95 mm** | — (not modelled) | new | +| D-cut flat chord | **13.00 mm** | — | new | +| Total axle protrusion | **65.5 mm** | ~60 mm est. | +5.5 mm | +| Base section length | **15.0 mm** | — | new | +| D-cut section length | **43.35 mm** | — | new | +| Tip / shoulder | **3.0 mm** | — | new | +| Bearing seat collar OD | **37.8 mm** | — | new | +| Tire OD | **254 mm** (10×2.125") | 170 mm motor OD only | — | +| Axle CL height above ground | **127 mm** | 310 mm (wrong) | −183 mm | + +`chassis_frame.scad` should be updated in a follow-on task to match Rev B values. + +--- + ## Structural / Fabricated Parts +### Prototype Base Plate (`prototype_baseplate.scad`) — Rev C + +> Batteries are removed from the base plate. Plate is now compact (680×130mm). +> Stem socket replaces battery tray. See Part B (stem clamp) below. + +| # | Part | Qty | Material | Cut size | Notes | +|---|------|-----|----------|----------|-------| +| 1 | Base plate | 1 | 6mm 5052-H32 Al **or** 8mm acrylic | 680×130mm blank | `RENDER="plate_2d"` → DXF | +| 2 | Dropout clamp — lower | 2 | 8mm 6061-T6 Al | 90×70mm blank | Round bore Ø16.51mm; `RENDER="clamp_lower_2d"` | +| 3 | Dropout clamp — upper | 2 | 8mm 6061-T6 Al | 90×70mm blank | D-cut bore; `RENDER="clamp_upper_2d"` | +| 4 | Stem flange ring | 2 | 6mm Al or acrylic | Ø82mm disc | One above + one below plate; `RENDER="stem_flange_2d"` | +| 5 | Vertical stem tube | 1 | 38.1mm OD × 1.5mm wall 6061-T6 Al | 1050mm length | 1.5" EMT conduit is a drop-in alternative | +| 6 | FC standoff M3×6mm nylon | 4 | Nylon | — | MAMBA F722S vibration isolation | +| 7 | Ø4mm × 16mm alignment pin | 8 | Steel dowel | — | Dropout clamp-to-plate alignment | + +### Battery Stem Clamp (`stem_battery_clamp.scad`) — Part B + | # | Part | Qty | Material | Notes | |---|------|-----|----------|-------| -| 1 | Main deck plate | 1 | 6mm 5052 aluminium plate, 640×220mm | CNC router or waterjet; all holes per `chassis_frame.scad` | -| 2 | Longitudinal rib (front) | 1 | 4mm 5052 aluminium, 600×40mm | Laser-cut; press-fit into deck slots | -| 3 | Longitudinal rib (rear) | 1 | 4mm 5052 aluminium, 600×40mm | Same file, symmetric | -| 4 | Motor fork bracket (L) | 1 | 8mm 6061 aluminium | CNC mill or FDM PETG @100% infill for prototyping | -| 5 | Motor fork bracket (R) | 1 | 8mm 6061 aluminium | Mirror of item 4 | -| 6 | Battery tray | 1 | 3mm PETG FDM or 3mm aluminium fold | `chassis_frame.scad` — `battery_tray()` module | -| 7 | FC mount plate / standoffs | 1 set | PETG or nylon FDM | Includes 4× M3 nylon standoffs, 6mm height | -| 8 | Jetson Nano mount plate | 1 | 4mm 5052 aluminium or 4mm PETG FDM | B01 58×58mm hole pattern | -| 9 | Front bumper bracket | 1 | 5mm PETG FDM | Saddle clamps for 22mm EMT conduit | -| 10 | Rear bumper bracket | 1 | 5mm PETG FDM | Mirror of item 9 | +| 8 | Collar half | 2 | PETG FDM (5 perimeters, 40% infill) | Print flat-side-down; mirror 2nd in slicer. Bore Ø38.6mm | +| 9 | Radial arm | 4 | 4mm 5052-H32 Al (laser-cut) **or** PETG FDM | `RENDER="arm_2d"` for DXF with `ARM_THICK=4`; or print at 8mm | +| 10 | Battery cradle | 4 | PETG FDM (4 perimeters, 30% infill) | U-channel, open top; holds 1 pack per cradle | +| 11 | M6×60 SHCS | 4 | SS | 2 collar clamping bolts × 2 sides | +| 12 | M6 hex nut | 4 | SS | Captured in collar nut pockets | +| 13 | M6×12 set screw | 2 | SS, cup-point | 1 per collar half for height lock | +| 14 | M4×20 SHCS | 8 (16 for 4) | SS | Arm-to-collar bolts (2 per arm) | +| 15 | M4×16 SHCS | 8 (16 for 4) | SS | Cradle-to-arm bolts (2 per cradle) | +| 16 | M4 hex nut | 16 (32 for 4) | SS | Nuts for items 14 + 15 | +| 17 | Velcro strap 25mm × 600mm | 4–8 | — | 1–2 per battery pack through cradle slots | + +### Full Chassis (`chassis_frame.scad`) — Rev A (placeholder values — pending Rev B update) + +| # | Part | Qty | Material | Notes | +|---|------|-----|----------|-------| +| 6 | Main deck plate | 1 | 6mm 5052 aluminium plate, 640×220mm | CNC router or waterjet; all holes per `chassis_frame.scad` | +| 7 | Longitudinal rib (front) | 1 | 4mm 5052 aluminium, 600×40mm | Laser-cut; press-fit into deck slots | +| 8 | Longitudinal rib (rear) | 1 | 4mm 5052 aluminium, 600×40mm | Same file, symmetric | +| 9 | Motor fork bracket (L) | 1 | 8mm 6061 aluminium | **Update fork slot to Ø16.51mm before cutting** | +| 10 | Motor fork bracket (R) | 1 | 8mm 6061 aluminium | Mirror of item 9 | +| 11 | Battery tray | 1 | 3mm PETG FDM or 3mm aluminium fold | `chassis_frame.scad` — `battery_tray()` module | +| 12 | FC mount plate / standoffs | 1 set | PETG or nylon FDM | Includes 4× M3 nylon standoffs, 6mm height | +| 13 | Jetson Nano mount plate | 1 | 4mm 5052 aluminium or 4mm PETG FDM | B01 58×58mm hole pattern | +| 14 | Front bumper bracket | 1 | 5mm PETG FDM | Saddle clamps for 22mm EMT conduit | +| 15 | Rear bumper bracket | 1 | 5mm PETG FDM | Mirror of item 14 | --- @@ -26,8 +80,9 @@ | # | Part | Qty | Source / Spec | Notes | |---|------|-----|---------------|-------| -| 11 | Hoverboard hub motor | 2 | Generic 6.5" / 170mm OD, 36V nominal | ~350W each; 14mm flat axle; confirm exact OD before cutting fork slots | -| 12 | Motor hall-sensor cable extension | 2 | 6-pin JST-PH 300mm | Route through deck cable slot | +| 16 | Hoverboard hub motor | 2 | 10×2.125" pneumatic tire, 36V nominal, ~350W | Axle: Ø16.11mm base / Ø15.95mm D-cut / 13mm flat; bearing seat Ø37.8mm — **all caliper-verified** | +| 17 | Motor hall-sensor cable extension | 2 | 6-pin JST-PH 300mm | Route through deck cable slot | +| 18 | Axle lock nut | 4 | M16×1.5 or thread-matched to actual axle tip | Confirm thread at tip before ordering; calipers show Ø≈10mm at tip | --- @@ -43,13 +98,27 @@ --- -## Battery +## Battery (Vertical Stem Mount — Rev C) + +> Batteries mount VERTICALLY on the stem carousel, **not** on the base plate. +> Each pack stands upright (420mm tall) in a cradle at the end of a radial arm. | # | Part | Qty | Spec | Notes | |---|------|-----|------|-------| -| 18 | LiPo / LiFePO4 pack | 1 | 24V (6S LiPo or 8S LiFePO4), 4Ah, ≤185×72×52mm | Confirm dims before printing tray; add 2mm clearance | -| 19 | Velcro strap 20mm wide | 2 | 300mm length | Route through tray strap slots | -| 20 | BMS board | 1 | Matched to cell chemistry | Mount externally on rear inner face of tray wall | +| 18 | Battery pack | 2–4 | 24V, **420×88×56 mm** each (caliper-verified) | Snap into battery cradle from above | +| 19 | BMS board | 1 | Matched to cell chemistry | Mount to stem or base plate underside; run wiring down stem | + +### Battery stem clamp — configuration guide + +| Config | Arm count | Carousel weight | Balance | Notes | +|--------|-----------|-----------------|---------|-------| +| 2-pack | 2 arms, 180° apart | ~1.4 kg | ✅ Symmetric | Minimum configuration | +| 4-pack | 4 arms, 90° apart | ~2.8 kg | ✅ Symmetric | Maximum practical config | +| 3-pack | 3 arms, 120° apart | ~2.1 kg | ⚠ Asymmetric mass | Needs counter-balance or avoid | + +### CG height tuning + +Slide entire carousel up/down the stem with M6 collar bolts loosened. Tighten at desired height. Typical balance point (initial estimate): batteries centred at 450–600 mm above base plate. Adjust in ≈50 mm increments during commissioning. --- @@ -64,18 +133,23 @@ ## Fasteners -| # | Part | Qty | Spec | -|---|------|-----|------| -| 23 | M5×16 SHCS | 24 | ISO 4762, SS | -| 24 | M5 hex nut | 24 | ISO 4032, SS | -| 25 | M4×12 SHCS | 12 | ISO 4762, SS | -| 26 | M4 hex nut | 12 | ISO 4032, SS | -| 27 | M3×10 SHCS | 20 | ISO 4762, SS | -| 28 | M3 hex nut | 20 | ISO 4032, SS | -| 29 | M3×6 BHCS | 8 | FC + Jetson board bolts | -| 30 | M14×1.5 axle nut | 4 | One each side per motor, flanged | Confirm axle thread pitch on actual motors | -| 31 | Serrated washer M14 | 4 | Axle anti-rotation | -| 32 | Flat washer M5 | 48 | SS | +| # | Part | Qty | Spec | Use | +|---|------|-----|------|-----| +| 20 | M5×16 SHCS | 16 | ISO 4762, SS | Dropout clamp bolts (4 per clamp × 4) | +| 21 | M5×20 SHCS | 8 | ISO 4762, SS | Stem flange bolts (4 per flange × 2) | +| 22 | M5 hex nut | 24 | ISO 4032, SS | | +| 23 | M4×20 SHCS | 16 | ISO 4762, SS | Arm-to-collar (2 per arm × 4 arms × 2) | +| 24 | M4×16 SHCS | 16 | ISO 4762, SS | Cradle-to-arm (2 per cradle × 4 arms × 2) | +| 25 | M4 hex nut | 32 | ISO 4032, SS | | +| 26 | M6×60 SHCS | 4 | ISO 4762, SS | Collar clamping bolts | +| 27 | M6 hex nut | 4 | ISO 4032, SS | Captured in collar pockets | +| 28 | M6×12 set screw | 2 | ISO 4026, SS cup-point | Stem height lock (1 per collar half) | +| 29 | M3×10 SHCS | 12 | ISO 4762, SS | FC mount + miscellaneous | +| 30 | M3×6 BHCS | 4 | ISO 4762, SS | FC board bolts | +| 31 | Axle lock nut (match axle tip thread) | 4 | Flanged, confirm thread | 2 per motor | +| 32 | Flat washer M5 | 32 | SS | | +| 33 | Flat washer M4 | 32 | SS | | +| 34 | Ø4×16 dowel pin | 8 | Steel | Dropout clamp alignment | --- diff --git a/chassis/prototype_baseplate.scad b/chassis/prototype_baseplate.scad new file mode 100644 index 0000000..5ab165f --- /dev/null +++ b/chassis/prototype_baseplate.scad @@ -0,0 +1,348 @@ +// ============================================================================= +// SaltyBot — Prototype Base Plate (Rev C — compact, stem-mount) +// Agent: sl-mechanical | 2026-02-28 +// +// Laser-cut or CNC-routed flat plate (6 mm Al / 8 mm acrylic). +// Uses CALIPER-VERIFIED hub motor axle measurements (see PR #7 / #11). +// +// ARCHITECTURE CHANGE (Rev C): +// Batteries are NO LONGER on the base plate. +// They stand vertically on a central stem via stem_battery_clamp.scad. +// The base plate is now compact — only axle dropouts + stem socket + FC mount. +// +// ── AXLE PROFILE (stepped D-cut, caliper-verified) ─────────────────────────── +// Zone │ Feature │ Ø / Width │ Length +// ───────┼──────────────────┼────────────────────┼────────── +// Base │ Round (near hub) │ Ø 16.11 mm │ 15.00 mm +// D-cut │ Round OD │ Ø 15.95 mm │ 43.35 mm +// │ Flat chord │ 13.00 mm │ +// Tip │ Shoulder/end │ — │ 3.00 mm +// Total │ Hub face → tip │ — │ 65.50 mm +// Bearing seat collar: Ø 37.8 mm +// Tire: 10 × 2.125" pneumatic (Ø 254 mm, 35 PSI) +// ============================================================================= + +$fn = 128; + +// ============================================================================= +// AXLE PARAMETERS — caliper-verified +// ============================================================================= + +AXLE_BASE_DIA = 16.11; +AXLE_BASE_LEN = 15.00; +AXLE_DCUT_DIA = 15.95; +AXLE_DCUT_FLAT = 13.00; +AXLE_DCUT_LEN = 43.35; +AXLE_TIP_LEN = 3.00; +AXLE_TOTAL = 65.50; +BEARING_SEAT_OD = 37.80; +TIRE_OD = 254.0; +AXLE_CL_HEIGHT = TIRE_OD / 2; // 127 mm above ground + +// ============================================================================= +// PLATE PARAMETERS +// ============================================================================= + +WHEELBASE = 600.0; // mm axle C/L to axle C/L +// Plate depth now driven only by structural + FC needs (no battery footprint). +PLATE_DEPTH = 130.0; // mm front-to-rear +PLATE_OVERHANG = 40.0; // mm plate past axle C/L each side +PLATE_THICK = 6.0; // mm + +// Fork slot +FORK_W = AXLE_BASE_DIA + 0.4; // 16.51 mm +FORK_DEPTH = 50.0; + +// Dropout clamp (two-piece sandwich) +CLAMP_L = 80.0; +CLAMP_H = 60.0; +CLAMP_THICK = 8.0; +CLAMP_BOLT_D = 5.3; // M5 +CLAMP_BOLT_DX = 22.0; +CLAMP_BOLT_DY = 22.0; +CLAMP_ALIGN_D = 4.1; // Ø4 pin + +// D-cut bore clearance +DCUT_CL = 0.3; + +// FC mount — MAMBA F722S 30.5 × 30.5 mm M3 +FC_PITCH = 30.5; +FC_HOLE_D = 3.2; +// FC is offset toward front of plate (away from stem) +FC_X_OFFSET = -40.0; // mm from plate centre (negative = front/motor side) + +// ============================================================================= +// STEM SOCKET PARAMETERS +// ============================================================================= + +STEM_OD = 38.1; // mm 1.5" EMT conduit OD +STEM_BORE = STEM_OD + 0.5; // 38.6 mm with clearance +// Flange ring (laser-cut, bolts above + below plate to grip tube): +STEM_FLANGE_OD = 82.0; // mm flange outer diameter +STEM_FLANGE_BC = 66.0; // mm bolt circle diameter (4× M5 at 90°) +STEM_FLANGE_T = 6.0; // mm = PLATE_THICK (flush-mount) +// Stem position: at plate centre (X=0, Y=0) + +// ============================================================================= +// UTILITIES +// ============================================================================= + +M3 = 3.2; M4 = 4.3; M5 = 5.3; +PLATE_X_HALF = WHEELBASE/2 + PLATE_OVERHANG; // ± 340 mm +DCUT_R = (AXLE_DCUT_DIA + 2*DCUT_CL) / 2; +DCUT_FC = AXLE_DCUT_FLAT + 2*DCUT_CL; + +// ============================================================================= +// RENDER CONTROL +// ============================================================================= +// +// "assembly" full 3-D preview +// "plate_2d" DXF — base plate +// "clamp_lower_2d" DXF — lower dropout clamp (× 2) +// "clamp_upper_2d" DXF — upper dropout clamp (× 2) +// "stem_flange_2d" DXF — stem flange ring (× 2, one above + one below plate) + +RENDER = "assembly"; + +if (RENDER == "assembly") { + assembly(); +} else if (RENDER == "plate_2d") { + projection(cut=true) translate([0,0,-PLATE_THICK/2]) base_plate(); +} else if (RENDER == "clamp_lower_2d") { + projection(cut=true) translate([0,0,-CLAMP_THICK/2]) clamp_lower(); +} else if (RENDER == "clamp_upper_2d") { + projection(cut=true) translate([0,0,-CLAMP_THICK/2]) clamp_upper(); +} else if (RENDER == "stem_flange_2d") { + projection(cut=true) translate([0,0,-STEM_FLANGE_T/2]) stem_flange(); +} + +// ============================================================================= +// ASSEMBLY +// ============================================================================= + +module assembly() { + color("Silver", 0.85) base_plate(); + + for (side = [-1, 1]) { + color("SteelBlue", 0.80) + translate([side * WHEELBASE/2, 0, PLATE_THICK]) + clamp_lower(); + color("CornflowerBlue", 0.80) + translate([side * WHEELBASE/2, 0, PLATE_THICK + CLAMP_THICK]) + clamp_upper(); + } + + // Stem flange rings (above and below plate) + color("DimGray", 0.70) + translate([0, 0, -STEM_FLANGE_T]) + stem_flange(); + color("DimGray", 0.70) + translate([0, 0, PLATE_THICK]) + stem_flange(); + + // Reference ghosts + %color("Orange", 0.25) + translate([0, 0, PLATE_THICK + STEM_FLANGE_T]) + cylinder(d=STEM_OD, h=800); // vertical stem + %for (side = [-1, 1]) + color("Tomato", 0.2) + translate([side * WHEELBASE/2, 0, 0]) + rotate([0, side*90, 0]) + axle_ghost(); +} + +// ============================================================================= +// BASE PLATE (Part A — compact) +// ============================================================================= + +module base_plate() { + R = 12; // corner radius + difference() { + // ── Outer profile ── + linear_extrude(PLATE_THICK) + minkowski() { + square([2*(PLATE_X_HALF - R), PLATE_DEPTH - 2*R], center=true); + circle(r=R); + } + + // ── Fork slots (open at ±X edges, semicircular tip) ────────────── + for (side = [-1, 1]) { + translate([side*(PLATE_X_HALF - FORK_DEPTH), -FORK_W/2, -1]) + cube([FORK_DEPTH + 1, FORK_W, PLATE_THICK + 2]); + translate([side*(PLATE_X_HALF - FORK_DEPTH), 0, -1]) + cylinder(d=FORK_W, h=PLATE_THICK + 2); + } + + // ── Bearing seat relief (prevents Ø37.8 mm collar binding on edge) ─ + for (side = [-1, 1]) + translate([side*PLATE_X_HALF - side*(BEARING_SEAT_OD/2 + 1), + -BEARING_SEAT_OD/2, -1]) + cube([BEARING_SEAT_OD/2 + 2, BEARING_SEAT_OD, PLATE_THICK + 2]); + + // ── Dropout clamp bolt through-holes ───────────────────────────── + for (side = [-1, 1]) + for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX]) + for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY]) + translate([side*WHEELBASE/2 + dx, dy, -1]) + cylinder(d=CLAMP_BOLT_D, h=PLATE_THICK + 2); + + // ── Alignment pin holes (Ø4) ────────────────────────────────────── + for (side = [-1, 1]) + for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8]) + translate([side*WHEELBASE/2, dy, -1]) + cylinder(d=CLAMP_ALIGN_D, h=PLATE_THICK + 2); + + // ── Stem socket bore ────────────────────────────────────────────── + translate([0, 0, -1]) + cylinder(d=STEM_BORE, h=PLATE_THICK + 2); + + // ── Stem flange bolt holes (4× M5, 90° pattern on STEM_FLANGE_BC) ─ + for (a = [0, 90, 180, 270]) + rotate([0, 0, a]) + translate([STEM_FLANGE_BC/2, 0, -1]) + cylinder(d=M5, h=PLATE_THICK + 2); + + // ── FC mount (MAMBA F722S 30.5 × 30.5 M3) ──────────────────────── + for (x = [FC_X_OFFSET - FC_PITCH/2, FC_X_OFFSET + FC_PITCH/2]) + for (y = [-FC_PITCH/2, FC_PITCH/2]) + translate([x, y, -1]) + cylinder(d=FC_HOLE_D, h=PLATE_THICK + 2); + + // ── Wiring / cable pass-through slots (2×, flanking stem) ───────── + for (dy = [-30, 30]) + hull() { + translate([15, dy, -1]) cylinder(d=14, h=PLATE_THICK + 2); + translate([-15, dy, -1]) cylinder(d=14, h=PLATE_THICK + 2); + } + + // ── Lightening slots (between FC zone and dropout zones) ────────── + for (sx = [-1, 1]) { + // One slot each side of stem, in the structural corridor + lx = sx * (WHEELBASE/4); + hull() { + translate([lx, -(PLATE_DEPTH/2 - 22), -1]) cylinder(d=18, h=PLATE_THICK+2); + translate([lx, (PLATE_DEPTH/2 - 22), -1]) cylinder(d=18, h=PLATE_THICK+2); + } + } + } +} + +// ============================================================================= +// STEM FLANGE RING (laser-cut, qty 2 — one above, one below plate) +// ============================================================================= + +module stem_flange() { + difference() { + cylinder(d=STEM_FLANGE_OD, h=STEM_FLANGE_T); + // Stem bore (tight fit — tube presses into flange) + translate([0, 0, -1]) + cylinder(d=STEM_BORE, h=STEM_FLANGE_T + 2); + // 4× M5 flange bolts + for (a = [0, 90, 180, 270]) + rotate([0, 0, a]) + translate([STEM_FLANGE_BC/2, 0, -1]) + cylinder(d=M5, h=STEM_FLANGE_T + 2); + } +} + +// ============================================================================= +// DROPOUT CLAMP — LOWER (round bore, base-section diameter) +// ============================================================================= + +module clamp_lower() { + difference() { + hull() { + translate([-CLAMP_L/2 + CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK); + translate([ CLAMP_L/2 - CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK); + } + // Round bore (base zone) + translate([0, 0, -1]) cylinder(d=AXLE_BASE_DIA + 0.4, h=CLAMP_THICK + 2); + // Slide-in slot (open toward wheel side) + translate([-CLAMP_L/2 - 1, -FORK_W/2, -1]) + cube([CLAMP_L/2 + 1, FORK_W, CLAMP_THICK + 2]); + // Clamp bolts + for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX]) + for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY]) + translate([dx, dy, -1]) cylinder(d=CLAMP_BOLT_D, h=CLAMP_THICK + 2); + // Alignment pins + for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8]) + translate([0, dy, -1]) cylinder(d=CLAMP_ALIGN_D, h=CLAMP_THICK + 2); + } +} + +// ============================================================================= +// DROPOUT CLAMP — UPPER (D-cut bore, anti-rotation) +// ============================================================================= + +module clamp_upper() { + dcut_r = DCUT_R; + dcut_d = sqrt(pow(dcut_r, 2) - pow(DCUT_FC/2, 2)); + + difference() { + hull() { + translate([-CLAMP_L/2 + CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK); + translate([ CLAMP_L/2 - CLAMP_H/2, 0, 0]) cylinder(d=CLAMP_H, h=CLAMP_THICK); + } + // D-cut bore + translate([0, 0, -1]) + linear_extrude(CLAMP_THICK + 2) + dcut_profile_2d(dcut_r, dcut_d); + // Slide-in slot + translate([-CLAMP_L/2 - 1, -FORK_W/2, -1]) + cube([CLAMP_L/2 + 1, FORK_W, CLAMP_THICK + 2]); + // Clamp bolts + for (dx = [-CLAMP_BOLT_DX, CLAMP_BOLT_DX]) + for (dy = [-CLAMP_BOLT_DY, CLAMP_BOLT_DY]) + translate([dx, dy, -1]) cylinder(d=CLAMP_BOLT_D, h=CLAMP_THICK + 2); + // Alignment pins + for (dy = [-CLAMP_BOLT_DY + 8, CLAMP_BOLT_DY - 8]) + translate([0, dy, -1]) cylinder(d=CLAMP_ALIGN_D, h=CLAMP_THICK + 2); + // Orientation emboss + translate([0, dcut_d + 1.5, CLAMP_THICK - 0.8]) + linear_extrude(1) + polygon([[0,0],[-3,-5],[3,-5]]); + } +} + +// ── D-cut 2D profile helper ─────────────────────────────────────────────────── +module dcut_profile_2d(r, flat_d) { + intersection() { + circle(r=r); + translate([-r - 1, -r - 1]) + square([2*(r+1), r + 1 + flat_d]); + } +} + +// ============================================================================= +// AXLE GHOST (visualisation only) +// ============================================================================= + +module axle_ghost() { + cylinder(d=BEARING_SEAT_OD, h=12); + translate([0,0,12]) cylinder(d=AXLE_BASE_DIA, h=AXLE_BASE_LEN); + translate([0,0,12+AXLE_BASE_LEN]) cylinder(d=AXLE_DCUT_DIA, h=AXLE_DCUT_LEN); +} + +// ============================================================================= +// DXF EXPORT +// ============================================================================= +// +// Part 1 — Base plate: +// openscad prototype_baseplate.scad -D 'RENDER="plate_2d"' -o baseplate.dxf +// +// Part 2 — Dropout clamp, lower (× 2): +// openscad prototype_baseplate.scad -D 'RENDER="clamp_lower_2d"' -o clamp_lower.dxf +// +// Part 3 — Dropout clamp, upper (× 2): +// openscad prototype_baseplate.scad -D 'RENDER="clamp_upper_2d"' -o clamp_upper.dxf +// +// Part 4 — Stem flange ring (× 2, one each side of plate): +// openscad prototype_baseplate.scad -D 'RENDER="stem_flange_2d"' -o stem_flange.dxf +// +// Materials: +// Plate + flanges : 6 mm 5052-H32 aluminium (preferred) +// 8 mm clear acrylic (quick proto) +// Dropout clamps : 8 mm 6061-T6 aluminium +// Stem tube : 38.1 mm OD × 1.5 mm wall 6061-T6 (or 1.5" EMT) +// Cut stem to ~1050 mm — allows batteries from ~100 mm to ~950 mm height. +// ============================================================================= diff --git a/chassis/stem_battery_clamp.scad b/chassis/stem_battery_clamp.scad new file mode 100644 index 0000000..8e73285 --- /dev/null +++ b/chassis/stem_battery_clamp.scad @@ -0,0 +1,378 @@ +// ============================================================================= +// SaltyBot — Battery Stem Clamp (Part B) +// Agent: sl-mechanical | 2026-02-28 +// +// HEIGHT-ADJUSTABLE battery carousel that slides on the central vertical stem. +// 2–4 battery packs stand UPRIGHT, arranged radially around the mast. +// +// HOW IT WORKS +// 1. Two collar halves clamp around the stem at the desired height. +// 2. Radial arms project outward from the collar (one per battery pack). +// 3. Each arm tip has a battery cradle — an upward-open U-channel that +// the pack slides into from above. +// 4. Velcro straps thread through cradle slots and cinch around the pack. +// 5. Loosen the M6 collar bolts → slide up/down for CG tuning. +// Tighten → locks in place. +// +// BATTERY (each pack, standing vertically): +// 420 mm tall × 88 mm wide × 56 mm deep (verified) +// +// ANGULAR LAYOUT +// BATT_COUNT = 2 → arms at 90° and 270° (±Y, balanced front/rear) +// BATT_COUNT = 4 → arms at 45°, 135°, 225°, 315° (each collar half owns 2) +// BATT_COUNT = 3 → arms at 90°, 210°, 330° +// +// PARTS (set RENDER= to export each) +// collar_half — 3D print × 2 (mirror pair, RENDER="collar_half") +// arm — laser-cut or print × BATT_COUNT (RENDER="arm_2d" for DXF) +// battery_cradle — 3D print × BATT_COUNT (RENDER="cradle") +// +// STEM +// 38.1 mm OD × 1.5 mm wall 6061-T6 aluminium tube (or 1.5" EMT conduit). +// Cut to ~1050 mm. Clamp can sit anywhere from 150 mm to 850 mm height. +// ============================================================================= + +$fn = 64; + +// ============================================================================= +// STEM +// ============================================================================= + +STEM_OD = 38.1; +STEM_BORE = STEM_OD + 0.5; // collar bore clearance + +// ============================================================================= +// COLLAR +// ============================================================================= + +COLLAR_H = 80.0; // mm taller = more grip / less slip risk +COLLAR_OD = 84.0; // mm outer diameter (wall = (84−38.6)/2 ≈ 22.7 mm) + +// Split plane: Y = 0 (each half is the +Y or −Y side) +// Clamping bolts go through both halves at (±COLLAR_BOLT_X, 0, Z) +COLLAR_BOLT_X = 24.0; // mm bolt ±X from stem axis +COLLAR_BOLT_D = 6.5; // M6 clearance +COLLAR_NUT_D = 11.0; // M6 hex nut AF + 0.5 mm tolerance (point-to-point ≈ 10.4, use 11) +COLLAR_NUT_H = 5.2; // M6 standard nut height + 0.2 mm + +// Height-lock / anti-rotation set screw (M6 thread on outer face of each half) +SETSCREW_D = 6.1; // through-hole for M6 set screw + +// Arm attachment pads on collar exterior (flat boss, one per arm) +ARM_PAD_W = 32.0; // mm pad width (tangential) +ARM_PAD_H = 18.0; // mm pad height +ARM_PAD_T = 4.0; // mm pad protrusion from collar surface +ARM_BOLT_D = 4.3; // M4 clearance (arm-to-collar bolt) +ARM_BOLT_SPAN = 16.0; // mm C/L-to-C/L of two arm attachment bolts + +// ============================================================================= +// ARMS & BATTERIES +// ============================================================================= + +BATT_COUNT = 4; // 2, 3, or 4 +BATT_L = 420.0; // mm pack height (vertical) +BATT_W = 88.0; // mm pack width (tangential) +BATT_D = 56.0; // mm pack depth (radial, into stem) +BATT_CL = 0.8; // mm all-round clearance in cradle + +ARM_REACH = 55.0; // mm collar surface → battery near face +ARM_W = 28.0; // mm arm width +ARM_THICK = 8.0; // mm arm thickness (3D-print); 4 mm if laser-cut Al +ARM_CRADLE_D = 4.3; // M4 clearance (cradle-to-arm bolt) + +// ============================================================================= +// BATTERY CRADLE +// ============================================================================= + +CRADLE_H = 80.0; // mm cradle height (pack extends BATT_L-CRADLE_H above) +CRADLE_WALL = 4.5; // mm wall thickness +CRADLE_STRAP_W = 25.0; // mm Velcro strap slot width +CRADLE_STRAP_T = 6.0; // mm slot height + +// ============================================================================= +// ANGULAR PLACEMENT +// ============================================================================= + +// First arm angle chosen so all arms are clear of the Y=0 split plane +ARM_START = (BATT_COUNT == 2) ? 90 : + (BATT_COUNT == 4) ? 45 : + /* 3 */ 90 ; + +// Helper: is arm i on the +Y half (side=+1) or −Y half (side=−1)? +// side = +1 → sin(angle) >= 0 +// side = -1 → sin(angle) < 0 +function arm_angle(i) = ARM_START + i * (360 / BATT_COUNT); +function arm_on_side(i, side) = + (side > 0) ? (sin(arm_angle(i)) >= -0.001) : + (sin(arm_angle(i)) <= 0.001); + +// ============================================================================= +// RENDER CONTROL +// ============================================================================= + +// "assembly" — full 3-D preview with ghosts +// "collar_half" — single collar half for printing (print 2, one mirrored) +// "arm" — single arm for printing or laser-cut +// "arm_2d" — 2-D DXF projection of arm +// "cradle" — single battery cradle for printing + +RENDER = "assembly"; + +if (RENDER == "assembly") { + assembly(); +} else if (RENDER == "collar_half") { + collar_half(side=1); +} else if (RENDER == "arm") { + arm(); +} else if (RENDER == "arm_2d") { + projection(cut=true) translate([0, 0, -ARM_THICK/2]) arm(); +} else if (RENDER == "cradle") { + battery_cradle(); +} + +// ============================================================================= +// ASSEMBLY +// ============================================================================= + +module assembly() { + // Collar halves + color("LightSlateGray", 0.88) collar_half(side= 1); + color("SlateGray", 0.88) collar_half(side=-1); + + // Arms + cradles at each battery position + for (i = [0 : BATT_COUNT - 1]) { + a = arm_angle(i); + rotate([0, 0, a]) { + // Arm: originates at collar surface, runs along +X + color("DimGray", 0.90) + translate([COLLAR_OD/2, 0, (COLLAR_H - ARM_THICK) / 2]) + arm(); + + // Cradle: at arm tip + color("SteelBlue", 0.85) + translate([COLLAR_OD/2 + ARM_REACH, + -(BATT_W/2 + BATT_CL + CRADLE_WALL), + (COLLAR_H - CRADLE_H) / 2]) + battery_cradle(); + + // Battery ghost (not for export) + %color("DarkGoldenrod", 0.30) + translate([COLLAR_OD/2 + ARM_REACH + CRADLE_WALL, + -(BATT_W/2 + BATT_CL), + (COLLAR_H - CRADLE_H) / 2]) + cube([BATT_D + 2*BATT_CL, BATT_W + 2*BATT_CL, BATT_L]); + } + } + + // Stem ghost + %color("Gray", 0.20) + translate([0, 0, -(COLLAR_H * 2)]) + cylinder(d=STEM_OD, h=COLLAR_H * 14); +} + +// ============================================================================= +// COLLAR HALF +// ============================================================================= +// Printed flat-side-down (split face = print bed). +// Print TWO: one as-is (side=+1), one mirrored in slicer (side=−1). +// They are identical; the mirror instruction handles orientation. +// +// Bolt pattern: +// 4× M6 through the flat face (2 per half at ±COLLAR_BOLT_X) +// M6 hex nut pockets on the flat face (captured before assembly) +// 1× M6 set screw on the outer curved surface (height lock) +// +// Arm attachment: +// Raised pad on outer curved surface at each arm angle for this half. +// 2× M4 through-holes per pad; M4 hex nut pocket on inside of collar wall. + +module collar_half(side = 1) { + mid_z = COLLAR_H / 2; + wall_t = (COLLAR_OD - STEM_BORE) / 2; + // Half of collar: the Y≥0 half (side=+1) or Y≤0 half (side=−1) + + difference() { + union() { + // ── Half-cylinder body ────────────────────────────────────── + intersection() { + cylinder(d=COLLAR_OD, h=COLLAR_H); + // Keep only the appropriate half + translate([-COLLAR_OD/2 - 1, + (side > 0) ? 0 : -COLLAR_OD - 1, + -1]) + cube([COLLAR_OD + 2, COLLAR_OD + 1, COLLAR_H + 2]); + } + + // ── Arm attachment pads ────────────────────────────────────── + for (i = [0 : BATT_COUNT - 1]) { + if (arm_on_side(i, side)) { + a = arm_angle(i); + rotate([0, 0, a]) + translate([COLLAR_OD/2, -ARM_PAD_W/2, + mid_z - ARM_PAD_H/2]) + cube([ARM_PAD_T, ARM_PAD_W, ARM_PAD_H]); + } + } + } + + // ── Stem bore ──────────────────────────────────────────────────── + translate([0, 0, -1]) + cylinder(d=STEM_BORE, h=COLLAR_H + 2); + + // ── Clamping bolt holes (2× through flat split face) ───────────── + // Bolt axis: along Y (perpendicular to split plane) + // Holes at (±COLLAR_BOLT_X, 0, COLLAR_H/3) and (±COLLAR_BOLT_X, 0, 2*COLLAR_H/3) + for (bx = [-COLLAR_BOLT_X, COLLAR_BOLT_X]) + for (bz = [COLLAR_H/3, 2*COLLAR_H/3]) + translate([bx, -1, bz]) + rotate([-90, 0, 0]) + cylinder(d=COLLAR_BOLT_D, h=COLLAR_OD/2 + 2); + + // ── M6 nut pockets on outer flat face of each half ─────────────── + // Pocket depth = COLLAR_NUT_H from the far curved side inward. + // This allows pre-installing the nuts before bolting the halves together. + for (bx = [-COLLAR_BOLT_X, COLLAR_BOLT_X]) + for (bz = [COLLAR_H/3, 2*COLLAR_H/3]) + translate([bx, side * (COLLAR_OD/2 - COLLAR_NUT_H), bz]) + rotate([-90, 0, 0]) + cylinder(d=COLLAR_NUT_D, h=COLLAR_NUT_H + 1, $fn=6); + + // ── Set screw hole (M6, on curved outer surface at mid-height) ──── + translate([0, side * (COLLAR_OD/2 + 1), COLLAR_H/2]) + rotate([90, 0, 0]) + cylinder(d=SETSCREW_D, h=COLLAR_OD/2 + 2); + + // ── Arm bolt holes + nut pockets (through collar wall per arm) ──── + for (i = [0 : BATT_COUNT - 1]) { + if (arm_on_side(i, side)) { + a = arm_angle(i); + for (dy = [-ARM_BOLT_SPAN/2, ARM_BOLT_SPAN/2]) + rotate([0, 0, a]) + translate([STEM_BORE/2 - 1, dy, mid_z]) + rotate([0, 90, 0]) { + // Through-hole (M4 clearance all the way) + cylinder(d=ARM_BOLT_D, + h=COLLAR_OD/2 - STEM_BORE/2 + ARM_PAD_T + 2); + // Nut pocket on bore interior face + cylinder(d=10, h=4.5, $fn=6); + } + } + } + } +} + +// ============================================================================= +// ARM +// ============================================================================= +// Flat bar, ARM_REACH × ARM_W × ARM_THICK. +// Collar end: 2× M4 clearance holes at ±ARM_BOLT_SPAN/2 in Y. +// Cradle end: 2× M4 clearance holes at ±(ARM_W/2 - 8) in Y. +// Can be laser-cut from 4 mm Al plate (reduce ARM_THICK to 4 in RENDER="arm_2d"). + +module arm() { + difference() { + translate([0, -ARM_W/2, 0]) + cube([ARM_REACH, ARM_W, ARM_THICK]); + + // Collar-end bolt holes (M4, match arm pad on collar) + for (dy = [-ARM_BOLT_SPAN/2, ARM_BOLT_SPAN/2]) + translate([8, dy, -1]) + cylinder(d=ARM_BOLT_D, h=ARM_THICK + 2); + + // Cradle-end bolt holes (M4) + for (dy = [-(ARM_W/2 - 8), ARM_W/2 - 8]) + translate([ARM_REACH - 10, dy, -1]) + cylinder(d=ARM_CRADLE_D, h=ARM_THICK + 2); + + // Lightening slot in centre (optional — reduces print material) + if (ARM_REACH > 40) { + slot_l = ARM_REACH - 34; + slot_w = ARM_W - 16; + translate([17, -slot_w/2, -1]) + hull() { + translate([slot_w/2, slot_w/2, 0]) cylinder(d=slot_w/2*0.8, h=ARM_THICK+2); + translate([slot_l - slot_w/2, slot_w/2, 0]) cylinder(d=slot_w/2*0.8, h=ARM_THICK+2); + } + } + } +} + +// ============================================================================= +// BATTERY CRADLE +// ============================================================================= +// U-channel, open top for pack insertion from above. +// Inner pocket: (BATT_D + 2*BATT_CL) radially × (BATT_W + 2*BATT_CL) tangentially. +// Cradle height CRADLE_H — battery extends (BATT_L − CRADLE_H) above the cradle. +// +// Strap slots: 2× horizontal slots through front+rear walls (Velcro through-pass). +// Base bolt holes: 2× M4 for arm attachment (arm bolts up through arm into cradle). + +module battery_cradle() { + cw = CRADLE_WALL; + id = BATT_D + 2*BATT_CL; // inner depth (radial, +X direction) + iw = BATT_W + 2*BATT_CL; // inner width (tangential, Y direction) + + difference() { + // Outer block + cube([id + 2*cw, iw + 2*cw, CRADLE_H]); + + // Battery slot (open top: subtract from cw to top + 1) + translate([cw, cw, -1]) + cube([id, iw, CRADLE_H + 2]); + + // Strap slots — through left and right walls (Y faces), 2 heights + for (sz = [CRADLE_H * 0.30, CRADLE_H * 0.65]) + translate([-1, cw + (iw - CRADLE_STRAP_W) / 2, sz]) + cube([id + 2*cw + 2, CRADLE_STRAP_W, CRADLE_STRAP_T]); + + // Arm attachment holes in floor (2× M4) + for (dy = [cw + iw/2 - ARM_BOLT_SPAN/2, + cw + iw/2 + ARM_BOLT_SPAN/2]) + translate([cw + id/2, dy, -1]) + cylinder(d=ARM_CRADLE_D, h=cw + 2); + + // Corner chamfers (front face — aids pack insertion) + chamfer_s = 5; + for (cy = [cw - 0.01, cw + iw - chamfer_s + 0.01]) + translate([cw - 0.01, cy, CRADLE_H - chamfer_s]) + rotate([0, 45, 0]) + cube([chamfer_s * 1.42, chamfer_s, chamfer_s * 1.42]); + } +} + +// ============================================================================= +// DXF / PRINT EXPORT +// ============================================================================= +// +// COLLAR HALF (3D print × 2 — print one as-is, mirror second in slicer): +// openscad stem_battery_clamp.scad -D 'RENDER="collar_half"' -o collar_half.stl +// Print settings: PETG, 5 perimeters, 40% infill, 0.2 mm layer, no supports needed +// (flat split face sits on bed; overhangs ≤ 45°) +// +// ARM — 3D print or laser-cut × BATT_COUNT: +// Print: openscad stem_battery_clamp.scad -D 'RENDER="arm"' -o arm.stl +// Laser (DXF): openscad stem_battery_clamp.scad \ +// -D 'RENDER="arm_2d"' -D 'ARM_THICK=4' -o arm.dxf +// Laser material: 4 mm 5052-H32 aluminium +// +// BATTERY CRADLE (3D print × BATT_COUNT): +// openscad stem_battery_clamp.scad -D 'RENDER="cradle"' -o cradle.stl +// Print settings: PETG, 4 perimeters, 30% infill, 0.25 mm layer +// +// ============================================================================= +// +// ASSEMBLY SEQUENCE +// 1. Print collar halves × 2, cradles × BATT_COUNT. +// 2. Laser-cut (or print) arms × BATT_COUNT. +// 3. Press M4 hex nuts into collar bore-face pockets. +// 4. Wrap collar halves around stem; thread M6 bolts through both halves. +// Do not fully tighten yet — position to desired height. +// 5. Bolt each arm to its collar pad (M4 × 20 SHCS from arm outward). +// 6. Bolt each cradle to its arm tip (M4 × 16 SHCS from below). +// 7. Drop battery packs into cradles from above; route Velcro straps. +// 8. Tighten M6 collar bolts (≈ 6 N·m each). Use M6 set screw for rotation lock. +// +// CG TUNING +// Loosen M6 collar bolts (do not fully remove). Slide entire carousel up/down. +// Re-tighten. Typical balance point: batteries at 400–600 mm above base plate. +// =============================================================================