; Generated by scripts/worm_farm_sources.ts from the chapter models.
(define-component worm-link
  ((number joint-clearance 0.6mm)
   (number joint-yaw-limit 35deg)
   (number joint-pitch-limit 20deg)
   (toggle has-socket true)
   (toggle has-ball true))
  (let* ((ball-radius 4mm)
         (joint-height 5mm)
         (socket-wall 2mm)
         (cavity-radius (+ ball-radius joint-clearance))
         (socket-outer-radius (+ cavity-radius socket-wall))
         (socket-height 12mm)
         (socket-throat-radius 3mm)
         (socket-top-lever (- socket-height joint-height))
         (body-relief-radius (+ joint-clearance
           (* socket-outer-radius (cos (deg->rad joint-pitch-limit)))
           (* socket-top-lever (sin (deg->rad joint-pitch-limit)))))
         (ball-offset 11mm)
         (socket-offset -12mm)
         (neck-start 1.2mm)
         (neck-length (- ball-offset neck-start))
         (neck-width 4.8mm)
         (neck-height 2.8mm)
         (window-bottom 1.6mm)
         (window-top (- socket-height window-bottom))
         (window-height (- window-top window-bottom))
         (window-center (/ (+ window-top window-bottom) 2))
         (window-corner-radius 1mm)
         (neck-motion-clearance 1.2mm)
         (passage-half-width (+ (/ neck-width 2) neck-motion-clearance))
         (ball-bed-pedestal-radius 1.4mm)
         (ball-bed-pedestal-height 1.3mm)
         (ball-bed-flat-height 0.6mm)
         (pedestal-motion-clearance 0.3mm)
         (bottom-throat-radius (+ pedestal-motion-clearance
           (* ball-bed-pedestal-radius (cos (deg->rad joint-pitch-limit)))
           (* joint-height (sin (deg->rad joint-pitch-limit)))))
         (cutter-length 16mm))
    (build
      (shape rounded-body
        (clip-plane
          (translate 0 0 4.8mm (scale 1.15 1.12 1 (sphere 7.2mm)))
          :origin '(0 0 0) :normal '(0 0 1) :keep "positive"))
      (shape body-with-joint-relief
        (if has-ball
          (difference rounded-body
            (translate ball-offset 0 -1mm (cylinder body-relief-radius 16mm)))
          rounded-body))
      (shape socket-housing
        (if has-socket
          (union body-with-joint-relief
            (translate socket-offset 0 0 (cylinder socket-outer-radius socket-height)))
          body-with-joint-relief))
      (shape socket-cavity
        (union
          (translate socket-offset 0 joint-height (sphere cavity-radius))
          (translate socket-offset 0 joint-height
            (cylinder socket-throat-radius socket-height))
          (translate socket-offset 0 -1mm
            (cylinder bottom-throat-radius (+ window-bottom 1mm)))))
      (shape neck-passage-base
        (translate (- cutter-length) 0 window-center
          (rotate 90deg 0 90deg
            (extrude
              (rounded-rect (* passage-half-width 2) window-height window-corner-radius)
              cutter-length))))
      (shape neck-motion-envelope
        (translate socket-offset 0 0
          (apply union
            (map (lambda (yaw) (rotate 0 0 yaw neck-passage-base))
              (linspace (- joint-yaw-limit) joint-yaw-limit 7)))))
      (shape captive-socket
        (if has-socket
          (difference socket-housing socket-cavity neck-motion-envelope)
          socket-housing))
      (shape grounded-ball
        (union
          (clip-plane
            (translate ball-offset 0 joint-height (sphere ball-radius))
            :origin (list 0 0 ball-bed-flat-height) :normal '(0 0 1) :keep "positive")
          (translate ball-offset 0 0
            (cylinder ball-bed-pedestal-radius ball-bed-pedestal-height))))
      (shape central-neck-bridge
        (translate neck-start 0 window-center
          (rotate 90deg 0 90deg
            (extrude (slot-overall neck-width neck-height) neck-length))))
      (result
        (if has-ball
          (union captive-socket central-neck-bridge grounded-ball)
          captive-socket)))))

(define-component tractor-chassis ((number axle-radius 3.2mm) (number body-clearance 0.3mm))
  (let* ((axle-height 5mm)
         (body (box 30mm 50mm 10mm))
         (engine (translate 0 -11mm 10mm (box 22mm 23mm 10mm)))
         (chimney (translate 0 -15mm 20mm (cylinder 2.5mm 12mm)))
         (cabin (translate 0 14mm 10mm
           (difference (box 24mm 18mm 23mm)
             (translate 0 0 3mm (box 26mm 12mm 16mm)))))
         (axle-bores (repeat-compound i 2
           (translate 0 (+ -15mm (* i 30mm)) axle-height
             (rotate 0 90deg 0
               (cylinder (+ axle-radius body-clearance) 34mm :align '(center center center)))))))
    (difference (union body engine chimney cabin) axle-bores)))

(define-component tractor-axle
  ((number axle-radius 3.2mm) (number axle-length 47.2mm)
   (number mouth-radius 1.8mm) (number cavity-radius 2.35mm)
   (number lip-depth 2.2mm) (number socket-depth 5.5mm))
  (difference
    (cylinder axle-radius axle-length)
    (translate 0 0 -1mm (cylinder mouth-radius (+ axle-length 2mm)))
    (translate 0 0 lip-depth (cylinder cavity-radius (- socket-depth lip-depth)))
    (translate 0 0 (- axle-length socket-depth)
      (cylinder cavity-radius (- socket-depth lip-depth)))))

(define-component tractor-wheel
  ((number radius 10mm) (number width 6mm)
   (number axle-radius 3.2mm) (number running-clearance 0.4mm))
  (difference (cylinder radius width)
    (translate 0 0 -1mm
      (cylinder (+ axle-radius running-clearance) (+ width 2mm)))))

(define-component tractor-rivet
  ((number mouth-radius 1.8mm) (number snap-interference 0.25mm)
   (number head-radius 4.8mm) (number head-thickness 1.6mm))
  (let* ((stem-radius (- mouth-radius 0.2mm))
         (barb-radius (+ mouth-radius snap-interference))
         (barb-base 4.3mm)
         (slot-bottom (+ head-thickness 0.8mm)))
    (difference
      (union
        (cylinder head-radius head-thickness)
        (translate 0 0 (- head-thickness 0.2mm) (cylinder stem-radius 3.1mm))
        (translate 0 0 barb-base (cone barb-radius 1mm 1.9mm)))
      (translate 0 0 slot-bottom (box 1.1mm 8mm 5mm)))))

(define-component fence_post ((number x 0mm) (number height 22mm))
  (translate x 0 0
    (union
      (cylinder 2mm height)
      (translate 0 0 height
        (cone 3mm 0mm 5mm)))))

(model
  (meta :title "Worm Farm")
  (params
    (number body-count 7 :label "Body links" :min 2 :max 10 :step 1 :frozen true)
    (number joint-yaw-limit 35deg :label "Side motion envelope" :min 25deg :max 40deg :step 5deg)
    (number joint-pitch-limit 20deg :label "Vertical motion envelope" :min 15deg :max 25deg :step 5deg)
    (number joint-clearance 0.6mm :label "Joint clearance" :min 0.4mm :max 0.8mm :step 0.05mm)
    (number wall 2mm :label "House wall" :min 1.5 :max 3 :step 0.5)
    (number roof_clearance 0.3mm :label "Roof clearance" :min 0.2 :max 0.6 :step 0.1)
    (toggle house_print_layout false :label "House print layout (changes export)")
    (number tooth_count 5 :label "Rake teeth" :min 3 :max 7 :step 1)
    (number wheel_radius 10mm :label "Wheel radius" :min 8 :max 12 :step 1)
    (number wheel_clearance 0.4mm :label "Wheel running clearance" :min 0.2 :max 0.6 :step 0.05)
    (number snap_interference 0.25mm :label "Rivet snap interference" :min 0.1 :max 0.35 :step 0.05)
    (toggle print_layout false :label "Print layout (changes export)")
    (number posts 6 :label "Fence posts" :min 3 :max 9 :step 1))
  (let* ((link-pitch 23mm))
    (part worm-head
      (translate -100mm -35mm 0mm
(build
        (shape head-body
          (worm-link :joint-yaw-limit joint-yaw-limit :joint-pitch-limit joint-pitch-limit :joint-clearance joint-clearance :has-socket false :has-ball true))
        (shape face-eyes
          (apply union (map (lambda (side)
              (translate -4.8mm (* side 3mm) 10.6mm (sphere 1.9mm))) '(-1 1))))
        (shape face-with-nose
          (union head-body face-eyes
            (translate -6.5mm 0 7mm (sphere 2.2mm))))
        (shape pupil-recesses
          (apply union (map (lambda (side)
              (translate -5.3mm (* side 3mm) 11.7mm (cylinder 0.8mm 3mm))) '(-1 1))))
        (shape rounded-horns
          (apply union
            (map (lambda (side)
              (translate -2.8mm (* side 4.8mm) 9mm
                (rotate (* side -10deg) 0 -8deg
                  (union
                    (cone 1.7mm 0.65mm 5.5mm)
                    (translate 0 0 5.3mm (sphere 0.8mm))))))
              '(-1 1))))
        (result (difference (union face-with-nose rounded-horns) pupil-recesses)))))
    (part worm-body-links
      (translate -100mm -35mm 0mm
(translate link-pitch 0 0
        (linear-array body-count link-pitch 0 0
          (worm-link :joint-yaw-limit joint-yaw-limit :joint-pitch-limit joint-pitch-limit :joint-clearance joint-clearance)))))
    (part worm-tail
      (translate -100mm -35mm 0mm
(translate (* (+ body-count 1) link-pitch) 0 0
        (build
          (shape tail-root
            (worm-link :joint-yaw-limit joint-yaw-limit :joint-pitch-limit joint-pitch-limit :joint-clearance joint-clearance :has-ball false))
          (shape tapered-tail-tip
            (clip-plane
              (hull
                (translate 5mm 0 2.4mm (sphere 3.4mm))
                (translate 10mm 0.8mm 1.8mm (sphere 2.7mm))
                (translate 14mm 1.5mm 1.4mm (sphere 2mm)))
              :origin '(0 0 0) :normal '(0 0 1) :keep "positive"))
          (result (union tail-root tapered-tail-tip)))))))

  (part mushroom-house
      (translate -65mm 40mm 0mm
(let* ((outside (cylinder 18mm 28mm))
           (room (translate 0 0 2mm (cylinder (- 18mm wall) 27mm)))
           (doorway (translate 0 -16mm 9mm
             (rotate 90deg 0 0 (cylinder 8.5mm 18mm :align '(center center center))))))
      (difference outside room doorway))))

  (part mushroom-roof
      (translate -65mm 40mm 0mm
(let* ((rim-radius (+ 18mm roof_clearance))
           (skirt-height 3mm)
           (cap (cone 26mm 2mm 26mm))
           (rim-opening (translate 0 0 -1mm (cylinder rim-radius (+ skirt-height 1mm))))
           (inside (translate 0 0 skirt-height (cone rim-radius 0mm rim-radius))))
      (translate (if house_print_layout 52mm 0mm) 0 (if house_print_layout 0mm 25mm)
        (difference cap rim-opening inside)))))

  (part tool-rake
      (translate -20mm 75mm 0mm
(let* ((tooth-length 12mm)
           (tooth-radius 1.3mm)
           (head-height tooth-length)
           (head-radius 2mm)
           (tooth-spacing 4mm)
           (head-length (+ (* (- tooth_count 1) tooth-spacing) (* head-radius 2)))
           (handle (translate 0 0 head-height
             (rotate -35deg 0 0 (cylinder 2mm 44mm))))
           (crossbar (translate 0 0 head-height
             (rotate 0 90deg 0
               (cylinder head-radius head-length :align '(center center center)))))
           (teeth (repeat-union i tooth_count
             (translate (* (- i (/ (- tooth_count 1) 2)) tooth-spacing) 0 0
               (cylinder tooth-radius tooth-length)))))
      (union handle crossbar teeth))))

  (let* ((axle-radius 3.2mm)
         (body-half-width 15mm)
         (wheel-width 6mm)
         (wheel-side-gap 2mm)
         (wheel-end-play 0.6mm)
         (wheel-center (+ body-half-width wheel-side-gap (/ wheel-width 2)))
         (axle-half-length (+ body-half-width wheel-side-gap wheel-width wheel-end-play))
         (axle-length (* 2 axle-half-length))
         (rivet-head-thickness 1.6mm)
         (body-lift (- wheel_radius 5mm)))
    (part tractor-chassis
      (translate 40mm 35mm 0mm
(translate 0 0 (if print_layout 0mm body-lift)
        (tractor-chassis :axle-radius axle-radius))))
    (part tractor-axles
      (translate 40mm 35mm 0mm
(repeat-compound i 2
        (let* ((axle (tractor-axle :axle-radius axle-radius :axle-length axle-length)))
          (if print_layout
            (translate (+ -28mm (* i 56mm)) 46mm 0 axle)
            (translate (- axle-half-length) (+ -15mm (* i 30mm)) wheel_radius
              (rotate 0 90deg 0 axle)))))))
    (part tractor-wheels
      (translate 40mm 35mm 0mm
(repeat-compound side 2
        (repeat-compound i 2
          (let* ((sign (- (* side 2) 1))
                 (wheel (tractor-wheel :radius wheel_radius :width wheel-width
                   :axle-radius axle-radius :running-clearance wheel_clearance)))
            (if print_layout
              (translate (* sign 32mm) (+ -15mm (* i 30mm)) 0 wheel)
              (translate (* sign (- wheel-center (/ wheel-width 2)))
                (+ -15mm (* i 30mm)) wheel_radius
                (rotate 0 (* sign 90deg) 0 wheel))))))))
    (part tractor-rivets
      (translate 40mm 35mm 0mm
(repeat-compound side 2
        (repeat-compound i 2
          (let* ((sign (- (* side 2) 1))
                 (rivet (tractor-rivet :snap-interference snap_interference
                   :head-thickness rivet-head-thickness)))
            (if print_layout
              (translate (+ -18mm (* side 24mm) (* i 12mm)) 46mm 0 rivet)
              (translate (* sign (+ axle-half-length rivet-head-thickness))
                (+ -15mm (* i 30mm)) wheel_radius
                (rotate 0 (* sign -90deg) 0 rivet)))))))))

  (part garden-fence
      (translate -15mm 100mm 0mm
(let* ((post_row
             (repeat-union i posts
               (fence_post :x (* i 9mm))))
           (rail_length (+ (* (- posts 1) 9mm) 4mm))
           (rail_center (/ (* (- posts 1) 9mm) 2))
           (bottom_rail
             (translate rail_center 0 8mm
               (box rail_length 2mm 3mm)))
           (top_rail
             (translate rail_center 0 16mm
               (box rail_length 2mm 3mm))))
      (union post_row bottom_rail top_rail))))

  (part garden-carrot
      (translate -15mm 100mm 0mm
(translate 20mm -12mm 0
      (loft 18mm
        (circle 1mm)
        (regular-polygon 6 5mm)))))
  (view peek_inside (offset-part mushroom-roof 0 0 24mm))
  (verify (tag closed-farm) (metric bad-edges (stl non-manifold-edge-count)) (expect bad-edges (= 0)))
  (verify (tag separate-mechanisms) (metric pieces (stl connected-component-count)) (expect pieces (= 25))))