replace front panel geometry with cetz diagram

1 files changed, 247 insertions, 3 deletions

diff --git a/mechanical-specifications.typ b/mechanical-specifications.typ
index 11fe05c..eb00fca 100644
--- a/mechanical-specifications.typ
+++ b/mechanical-specifications.typ
@@ -950,10 +950,254 @@ interlocking U-shaped steel channel:
 ===== Front panel <front-panel>
 
 #figure(
-  image("pictures/front-panel-geometry.svg"),
-  caption: [Front channel construction],
-) <figure-front-channel-construction>
+  cetz.canvas({
+    import cetz.draw: *
+
+    // Scale factor: 1 mm = 0.050 drawing units
+    let s = 0.050
+
+    let h-total = 177.8 * s // 8.890 mm
+    let h-body = 165.1 * s // 8.255 mm
+    let h-lip = 6.35 * s // 0.3175 mm (6.35 mm top/bottom lips)
+    let w = 38.0 * s // 1.900 mm (panel width)
+    let f = 8.0 * s // 0.400 mm (8 mm L-channel flange overlap)
+
+    let y-bot = 0
+    let y-lip-bot = h-lip
+    let y-lip-top = h-total - h-lip
+    let y-top = h-total
+
+    // Helper: Draw M3 clearance hole (3.2 mm diameter)
+    let draw-m3-hole(cx, cy) = {
+      circle((cx, cy), radius: 1.6 * s, fill: white, stroke: 0.8pt + black)
+      line((cx - 2.5 * s, cy), (cx + 2.5 * s, cy), stroke: 0.3pt + luma(120))
+      line((cx, cy - 2.5 * s), (cx, cy + 2.5 * s), stroke: 0.3pt + luma(120))
+    }
+
+    // Helper: Draw M3 countersunk hole (concentric circles + crosshair)
+    let draw-csink(cx, cy) = {
+      circle((cx, cy), radius: 3.0 * s, fill: white, stroke: 0.8pt + black)
+      circle((cx, cy), radius: 1.6 * s, fill: luma(200), stroke: 0.5pt + black)
+      line((cx - 4.0 * s, cy), (cx + 4.0 * s, cy), stroke: 0.3pt + luma(120))
+      line((cx, cy - 4.0 * s), (cx, cy + 4.0 * s), stroke: 0.3pt + luma(120))
+    }
+
+    // ==========================================
+    // 1. FRONT ELEVATION (38.0 x 177.8 mm)
+    // ==========================================
+    let x-front-start = 0
+    let x-front-end = x-front-start + w
+    let x-front-mid = (x-front-start + x-front-end) / 2
+
+    // View Title
+    content((x-front-mid, y-top + 0.8), text(
+      size: 8.5pt,
+      weight: "bold",
+    )[FRONT ELEVATION])
+
+    // Main Panel Outer Boundary
+    rect(
+      (x-front-start, y-bot),
+      (x-front-end, y-top),
+      fill: luma(245),
+      stroke: 1.2pt + black,
+    )
+
+    // Lip Limit Boundary Indicators (Dashed horizontal lines at 6.35 mm from top/bottom)
+    line(
+      (x-front-start, y-lip-bot),
+      (x-front-end, y-lip-bot),
+      stroke: (paint: luma(110), thickness: 0.7pt, dash: "dashed"),
+    )
+    line(
+      (x-front-start, y-lip-top),
+      (x-front-end, y-lip-top),
+      stroke: (paint: luma(110), thickness: 0.7pt, dash: "dashed"),
+    )
+
+    // Centered M3 Panel Mounting Holes in Top and Bottom Lips
+    draw-m3-hole(x-front-mid, h-lip / 2)
+    draw-m3-hole(x-front-mid, h-total - h-lip / 2)
+
+    // L-Channel Attachment Countersunk Holes (X = 4.0 mm, Y = 30.0 mm and 135.0 mm from body start)
+    let y-hole-lower = y-lip-bot + 30.0 * s
+    let y-hole-upper = y-lip-bot + 135.0 * s
+    let x-hole-lchannel = x-front-start + 4.0 * s
+
+    draw-csink(x-hole-lchannel, y-hole-lower)
+    draw-csink(x-hole-lchannel, y-hole-upper)
+
+    // Dimension: Panel Width (38.0 mm)
+    line(
+      (x-front-start, y-bot),
+      (x-front-start, y-bot - 0.6),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-end, y-bot),
+      (x-front-end, y-bot - 0.6),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-start, y-bot - 0.55),
+      (x-front-end, y-bot - 0.55),
+      mark: (start: "stealth", end: "stealth"),
+      mark-size: 0.10,
+      stroke: 0.6pt + black,
+    )
+    content((x-front-mid, y-bot - 0.85), text(size: 7pt)[$qty(38.0, "mm")$])
+
+    // Dimension: Total Height (177.8 mm / 4U)
+    line(
+      (x-front-start, y-bot),
+      (x-front-start - 0.6, y-bot),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-start, y-top),
+      (x-front-start - 0.6, y-top),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-start - 0.55, y-bot),
+      (x-front-start - 0.55, y-top),
+      mark: (start: "stealth", end: "stealth"),
+      mark-size: 0.10,
+      stroke: 0.6pt + black,
+    )
+    content(
+      (x-front-start - 0.85, (y-bot + y-top) / 2),
+      text(size: 7pt)[$qty(177.8, "mm")$ ($qty(4, "U")$)],
+      angle: 90deg,
+    )
+
+    // Dimension: Lip Height (6.35 mm)
+    line(
+      (x-front-end, y-top),
+      (x-front-end + 0.6, y-top),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-end, y-lip-top),
+      (x-front-end + 0.6, y-lip-top),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-end + 0.55, y-lip-top),
+      (x-front-end + 0.55, y-top),
+      mark: (start: "stealth", end: "stealth"),
+      mark-size: 0.08,
+      stroke: 0.6pt + black,
+    )
+    content(
+      (x-front-end + 1.2, (y-lip-top + y-top) / 2),
+      text(size: 6.5pt)[$qty(6.35, "mm")$],
+    )
+
+    // Dimension: Body Height (165.1 mm)
+    line(
+      (x-front-end, y-lip-bot),
+      (x-front-end + 0.6, y-lip-bot),
+      stroke: 0.4pt + luma(140),
+    )
+    line(
+      (x-front-end + 0.55, y-lip-bot),
+      (x-front-end + 0.55, y-lip-top),
+      mark: (start: "stealth", end: "stealth"),
+      mark-size: 0.10,
+      stroke: 0.6pt + black,
+    )
+    content(
+      (x-front-end + 0.85, (y-lip-bot + y-lip-top) / 2),
+      text(size: 7pt)[$qty(165.1, "mm")$],
+      angle: -90deg,
+    )
 
+    // ==========================================
+    // 2. REAR ELEVATION (INNER FACE: 38.0 x 177.8 mm)
+    // ==========================================
+    let x-rear-start = 4.5
+    let x-rear-end = x-rear-start + w
+    let x-rear-mid = (x-rear-start + x-rear-end) / 2
+
+    // View Title
+    content((x-rear-mid, y-top + 0.8), text(
+      size: 8.5pt,
+      weight: "bold",
+    )[REAR ELEVATION (INNER FACE)])
+
+    // Painted Central Surface Area
+    rect(
+      (x-rear-start, y-bot),
+      (x-rear-end, y-top),
+      fill: luma(225),
+      stroke: 1.2pt + black,
+    )
+
+    // Masked Unpainted Area 1: Top Lip (6.35 mm full width)
+    rect(
+      (x-rear-start, y-lip-top),
+      (x-rear-end, y-top),
+      fill: luma(250),
+      stroke: (paint: luma(120), thickness: 0.6pt, dash: "dashed"),
+    )
+
+    // Masked Unpainted Area 2: Bottom Lip (6.35 mm full width)
+    rect(
+      (x-rear-start, y-bot),
+      (x-rear-end, y-lip-bot),
+      fill: luma(250),
+      stroke: (paint: luma(120), thickness: 0.6pt, dash: "dashed"),
+    )
+
+    // Masked Unpainted Area 3: L-Channel Front Flange Contact Strip (8 mm along right side in rear view)
+    rect(
+      (x-rear-end - f, y-lip-bot),
+      (x-rear-end, y-lip-top),
+      fill: luma(250),
+      stroke: (paint: luma(120), thickness: 0.6pt, dash: "dashed"),
+    )
+
+    // Center Painted Label
+    content(
+      (x-rear-start + (w - f) / 2, (y-lip-bot + y-lip-top) / 2),
+      text(size: 7.5pt, fill: luma(100))[Painted Surface],
+    )
+
+    // M3 Lip Holes in Rear View
+    draw-m3-hole(x-rear-mid, h-lip / 2)
+    draw-m3-hole(x-rear-mid, h-total - h-lip / 2)
+
+    // L-Channel Attachment Holes in Rear View (X = 38.0 - 4.0 = 34.0 mm in rear view)
+    let x-hole-rear = x-rear-end - 4.0 * s
+    draw-m3-hole(x-hole-rear, y-hole-lower)
+    draw-m3-hole(x-hole-rear, y-hole-upper)
+
+    // Masked Contact Area Callout Annotations
+    line(
+      (x-rear-mid, y-top - h-lip / 2),
+      (x-rear-end + 0.5, y-top + 0.3),
+      stroke: 0.5pt + black,
+    )
+    content(
+      (x-rear-end + 0.55, y-top + 0.3),
+      text(size: 6.5pt)[Masked unpainted lip (chassis grounding)],
+      anchor: "south-west",
+    )
+
+    line(
+      (x-rear-end - f / 2, y-hole-upper + 10.0 * s),
+      (x-rear-end + 0.5, y-hole-upper + 10.0 * s),
+      stroke: 0.5pt + black,
+    )
+    content(
+      (x-rear-end + 0.55, y-hole-upper + 10.0 * s),
+      text(size: 6.5pt)[Masked 8 mm flange contact strip],
+      anchor: "west",
+    )
+  }),
+  caption: [Cassette Front Panel technical drawings showing Front Elevation (with countersunk L-channel attachment holes and lip mounting holes) and Rear Elevation (inner face detailing masked unpainted EMI contact areas).],
+) <figure-cassette-front-panel-diagram>
 / Geometry: $qty(177.8, "mm") times qty(38.0, "mm")$, body section
   $qty(165.1, "mm")$
 / Holes: Features Countersunk Through-Holes corresponding to the L-Channel's