Add car-park wash-coin holder

Add first draft

Signed-off-by: Knut Ahlers <knut@ahlers.me>

Improve model after first assembly

- bottom cap fitting: was too tight
- top cap cover: 0.5 * width allows coin to fall out
- inner spacing: was too high for spring to cover

Signed-off-by: Knut Ahlers <knut@ahlers.me>

Generate waschmarken STL

Signed-off-by: Knut Ahlers <knut@ahlers.me>

README.md

@@ -15,3 +15,4 @@ In case you have use for those models thankfully to Github you can preview all m
 | [`sonoff_dev_housing.stl`](sonoff_dev_housing.stl) | [`sonoff_dev_housing.jscad`](sonoff_dev_housing.jscad) | 0.2.6 | Sonoff DEV box for lamp post |
 | [`tas6515_swimmer.stl`](tas6515_swimmer.stl) | [`tas6515_swimmer.jscad`](tas6515_swimmer.jscad) | 0.1.10 | Tassimo TAS6515 swimmer replacement |
 | [`towelholder.stl`](towelholder.stl) | [`towelholder.jscad`](towelholder.jscad) | 0.1.1 | Kitchen-towel holder for fridge |
+| [`waschmarken.stl`](waschmarken.stl) | [`waschmarken.jscad`](waschmarken.jscad) | 0.1.0 | Spring-holder for coins for the car-wash-park |

waschmarken.jscad

@@ -0,0 +1,128 @@
+/*
+ * title      : Spring-holder for coins for the car-wash-park
+ * author     : Knut Ahlers
+ * revision   : 0.1.0
+ */
+
+const { cuboid, cylinder } = require('@jscad/modeling').primitives
+const { subtract, union } = require('@jscad/modeling').booleans
+const { translate } = require('@jscad/modeling').transforms
+
+const coinDia = 27.0 // mm
+const coinHeight = 1.8 // mm
+const coinToWallSpacing = 0.25 // mm
+const springCompressedHeight = 9 // mm
+const springRelaxedHeight = 30 // mm
+const springRadius = 9 // mm
+const wallThickness = 1.5 // mm
+
+function bottomCap() {
+  return union(
+    translate([0, 0, 0.5 * wallThickness], cylinder({
+      height: wallThickness,
+      radius: outerRadius(),
+      segments: 64,
+    })),
+    translate([0, 0, 0.5 * (wallThickness + springCompressedHeight)], subtract(
+      cylinder({
+        height: wallThickness + springCompressedHeight,
+        radius: outerRadius() - wallThickness - 0.5 * coinToWallSpacing,
+        segments: 64,
+      }),
+      cylinder({
+        height: wallThickness + springCompressedHeight,
+        radius: springRadius,
+        segments: 64,
+      })
+    ))
+  )
+}
+
+function cylinderHeight() {
+  return innerSpacingHeight() + wallThickness
+}
+
+function innerBlock() {
+  return translate([0, 0, coinHeight], subtract(
+    cylinder({
+      height: 2 * coinHeight,
+      radius: 0.5 * coinDia,
+      segments: 64,
+    }),
+    translate([0, 0, 0.5 * coinHeight], subtract(
+      cylinder({
+        height: coinHeight,
+        radius: springRadius + 0.75,
+        segments: 64,
+      }),
+      cylinder({
+        height: coinHeight,
+        radius: springRadius - 0.75,
+        segments: 64,
+      })
+    ))
+  ))
+}
+
+function innerSpacingHeight() {
+  return springRelaxedHeight - 0.5 * coinHeight
+}
+
+function outerRadius() {
+  return 0.5 * coinDia + coinToWallSpacing + wallThickness
+}
+
+function topCap() {
+  const topCapHeight = 1.5 * coinHeight + wallThickness
+  const topCapInnerRadius = 0.5 * coinDia + coinToWallSpacing
+  const topCapRadius = topCapInnerRadius + wallThickness
+
+  return translate([0, 0, 0.5 * topCapHeight], subtract(
+    cylinder({
+      height: topCapHeight,
+      radius: topCapRadius,
+      segments: 64,
+    }),
+    subtract(
+      translate([0, 0.5 * topCapRadius, 0], cuboid({
+        size: [2 * topCapRadius, topCapRadius, topCapHeight],
+      })),
+      translate([0, 0, 0.5 * topCapHeight - 0.5 * wallThickness], cylinder({
+        height: wallThickness,
+        radius: 0.65 * topCapRadius,
+        segments: 64,
+      }))
+    ),
+    translate([0, 0, -0.5 * wallThickness], cylinder({
+      height: 1.5 * coinHeight,
+      radius: topCapInnerRadius,
+      segments: 64,
+    }))
+  ))
+}
+
+function main() {
+  return union(
+    translate([0, 0, 0.5 * cylinderHeight()], union(
+      subtract(
+        cylinder({
+          height: cylinderHeight(),
+          radius: outerRadius(),
+          segments: 64,
+        }),
+        cylinder({
+          height: cylinderHeight(),
+          radius: 0.5 * coinDia + coinToWallSpacing,
+          segments: 64,
+        })
+      ),
+      translate([0, 0, 0.5 * cylinderHeight()], topCap())
+    )),
+    translate([2.5 * outerRadius(), 0, 0], bottomCap()),
+    translate([-2.5 * outerRadius(), 0, 0], innerBlock())
+  )
+}
+
+module.exports = { main }
+
+// vim: set ft=javascript :