Compost Bin Builder — SketchUp 2020

sketchup.compost.rb

# ============================================================
#  Compost Bin Builder — SketchUp 2020
# ============================================================
#  How to use:
#    1. Open SketchUp 2020
#    2. Go to Extensions > Ruby Console
#    3. Paste this entire script and press Enter
#    4. The model builds automatically — File > Save As to keep it
#
#  Axes:
#    X = left → right
#    Y = back → front  (0 = outer back face of back board)
#    Z = up             (0 = ground level)
#
#  All dimensions in mm, converted to inches for SketchUp internally.
# ============================================================

model = Sketchup.active_model
model.entities.clear!
model.start_operation('Build Compost Bin', true)

F = 1.0 / 25.4   # mm to inches

add_box = lambda do |model, x, y, z, w, d, h|
  grp  = model.entities.add_group
  ents = grp.entities
  pts  = [
    Geom::Point3d.new( x    * F,  y    * F,  z * F),
    Geom::Point3d.new((x+w) * F,  y    * F,  z * F),
    Geom::Point3d.new((x+w) * F, (y+d) * F,  z * F),
    Geom::Point3d.new( x    * F, (y+d) * F,  z * F)
  ]
  face = ents.add_face(pts)
  face.pushpull(h * F) if face
  grp
end

# ── Dimensions (mm) ─────────────────────────────────────────
POST   = 75.0   # post cross-section (square)
BT     = 22.0   # board thickness
BH     = 150.0  # board height per layer
LAYERS = 7      # boards stacked  → 1050 mm total wall height
PHT    = 1500.0 # post height shown (notional 300 mm below grade + 1200 mm above)
BURY   = 600.0  # how deep posts go into the ground (shown below z=0)
INT    = 1000.0 # interior clear dimension (both X and Y)
GAP    =  26.0  # drop-board channel gap (22 mm board + 4 mm clearance)

# Derived
OW = POST*2 + BT*2 + INT   # outer width = 1194 mm

# ── Y key positions (back → front) ──────────────────────────
#   -POST  …  0          B2 post (outside / behind back board)
#    0     … BT          Back board (22 mm thick)
#    BT    … BT+POST     L1 / R1 posts
#    BT+POST … BT+POST+INT   Side boards & interior (1000 mm)
#    BT+POST+INT-POST … BT+POST+INT   L3 / R3 posts
#    BT+POST+INT … BT+POST+INT+GAP   Drop-board channel (26 mm)
#    BT+POST+INT+GAP … +POST          FL / FR guide posts

# ── POSTS ───────────────────────────────────────────────────

POST_TOP = 1000   # 1m above ground
POST_H   = 1800   # full post length (1.8m), extrudes downward leaving 80cm below z=0

# B2  — centre-back bracing post, sits OUTSIDE (behind) the back board
add_box.call(model, OW/2 - POST/2,  -POST,  POST_TOP,  POST, POST, -POST_H)

# Left posts: L1 (back), L2 (mid), L3 (front-end of side boards)
add_box.call(model, 0,  BT,                        POST_TOP,  POST, POST, -POST_H)  # L1
add_box.call(model, 0,  BT + INT/2 - POST/2,       POST_TOP,  POST, POST, -POST_H)  # L2
add_box.call(model, 0,  BT + INT - POST,            POST_TOP,  POST, POST, -POST_H)  # L3

# Right posts: R1, R2, R3  (mirror of left)
add_box.call(model, OW-POST,  BT,                  POST_TOP,  POST, POST, -POST_H)  # R1
add_box.call(model, OW-POST,  BT + INT/2 - POST/2, POST_TOP,  POST, POST, -POST_H)  # R2
add_box.call(model, OW-POST,  BT + INT - POST,      POST_TOP,  POST, POST, -POST_H)  # R3

# Guide posts: FL, FR  — define the front drop-board slide channel
add_box.call(model, 0,         BT + INT + GAP,  POST_TOP,  POST, POST, -POST_H)  # FL
add_box.call(model, OW - POST, BT + INT + GAP,  POST_TOP,  POST, POST, -POST_H)  # FR

# ── BOARDS ──────────────────────────────────────────────────

# Back boards (7 stacked) — outside-back of L1/R1, screwed from outside in
LAYERS.times do |i|
  add_box.call(model,  0,  0,  (i+1)*BH,  OW,  BT,  -BH)
end

# Left side boards (7 stacked) — flush with inner face of back board, screwed inside out
LAYERS.times do |i|
  add_box.call(model,  POST,  BT,  (i+1)*BH,  BT,  INT,  -BH)
end

# Right side boards (7 stacked) — flush with inner face of back board, screwed inside out
LAYERS.times do |i|
  add_box.call(model,  POST+BT+INT,  BT,  (i+1)*BH,  BT,  INT,  -BH)
end

# Front drop boards (7 stacked) — removable, shown in channel position
drop_y = BT + INT
LAYERS.times do |i|
  add_box.call(model,  0,  drop_y,  (i+1)*BH,  OW,  BT,  -BH)
end

# ── Finish ──────────────────────────────────────────────────
model.commit_operation
model.active_view.zoom_extents

puts ""
puts "=== Compost bin built! ==="
puts "  Outer footprint:  #{(OW).round} mm wide x #{(BT+POST+INT+GAP+POST).round} mm deep"
puts "  Interior clear:   #{INT.round} x #{INT.round} mm"
puts "  Wall height:      #{(LAYERS*BH).round} mm (#{LAYERS} boards x #{BH.round} mm)"
puts "  Posts:            9 total (L1-3, R1-3, FL, FR, B2)"
puts ""
puts "  Tip: use View > Toolbars > Styles to apply a wood material,"
puts "  or select all geometry and use the Paint Bucket tool."
puts "  Save with File > Save As to keep the .skp file."