Add first revision of change holder

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

README.md

@@ -6,6 +6,7 @@ In case you have use for those models thankfully to Github you can preview all m
 
 | Model | Source | Version | Title |
 | ----- | ------ | ------- | ----- |
+| [`change-holder.stl`](change-holder.stl) | [`change-holder.jscad`](change-holder.jscad) | 0.1.0 | Spare-Change holder |
 | [`razorholder.stl`](razorholder.stl) | [`razorholder.jscad`](razorholder.jscad) | 0.1.1 | Holder for T-Shape razor |
 | [`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 |

change-holder.jscad

@@ -0,0 +1,76 @@
+/*
+ * title      : Spare-Change holder
+ * author     : Knut Ahlers
+ * revision   : 0.1.0
+ */
+
+const coinCount = 15
+const coinDiameters = [
+  24, // 1 EUR
+  26, // 2 EUR
+]
+const coinHeight = 3 // Use max coin thickness + a little but less than 2 coins
+const fingerDia = 18 // Measure your finger, should be less than the smallest coin diameter
+const height = coinCount * coinHeight // Think of something to hold all the coins but not too big
+const wall = 2 // Something you're comfortable with to print and hold your coin
+
+const blockHeight = () => coinDiameters.sort().reverse()[0] + wall
+const blockWidth = () => coinDiameters.reduce((sum, v) => sum + v) + (coinDiameters.length + 1) * wall
+
+const calcMove = (posY, slotDia) => slotDia / 2 + posY
+
+/* exported main */
+function main() {
+  // Create a block containing everything
+  let obj = cube({ size: [
+    height,
+    blockWidth(),
+    blockHeight(),
+  ], center: true }).translate([0, blockWidth() / 2, 0])
+
+  let posY = wall
+  for (const slotDia of coinDiameters) {
+    // Remove pipes holding the coins
+    obj = difference(obj, cylinder({
+      center: true,
+      h: height,
+      r: slotDia / 2,
+    })
+      .rotateY(90)
+      .translate([
+        wall,
+        calcMove(posY, slotDia),
+        blockHeight() / 2 - slotDia / 2,
+      ]))
+
+    // Remove finger access to coins
+    obj = difference(obj, cube({ size: [
+      height,
+      fingerDia,
+      slotDia / 2,
+    ], center: true })
+      .translate([
+        0,
+        posY + slotDia / 2,
+        blockHeight() / 2 - slotDia / 4,
+      ]))
+
+    // Remove one-coin-slot to pull coins out
+    obj = difference(obj, cube({ size: [
+      coinHeight,
+      slotDia,
+      slotDia / 2,
+    ], center: true })
+      .translate([
+        height / -2 + wall + coinHeight / 2,
+        posY + slotDia / 2,
+        blockHeight() / 2 - slotDia / 4,
+      ]))
+
+    posY += slotDia + wall
+  }
+
+  return obj
+}
+
+// vim: set ft=javascript: