Add model for the tape fan [WIP]

tape_fan.scad

@@ -0,0 +1,44 @@
+$fn = 200;
+
+w = 1;
+h = 1;
+
+function fn(a, b) = round(sqrt(pow(a[0]-b[0],2) + (pow(a[1]-b[1], 2))));
+
+module shape(i) cylinder(h, max(w/2*((i^2.1)*0.01),0.5), max(w/2*((i^2.1)*0.01),0.5), $fn=12);
+
+function b_pts(pts, n, idx) =
+    len(pts)>2 ?
+        b_pts([for(i=[0:len(pts)-2])pts[i]], n, idx) * n*idx
+            + b_pts([for(i=[1:len(pts)-1])pts[i]], n, idx) * (1-n*idx)
+        : pts[0] * n*idx
+            + pts[1] * (1-n*idx);
+
+module b_curve(pts)
+    let (idx=fn(pts[0], pts[len(pts)-1]), n = 1/idx) {
+        for (i= [0:idx-1])
+        hull(){
+	  translate(b_pts(pts, n, i)) shape(i); // change i to 1 for constant with
+           translate(b_pts(pts, n, i+1)) shape(i); // change i to 1 for constant with
+    };
+}
+
+module spike() {
+  polygon([[0, 0], [10, 0], [5, 50]]);
+}
+
+blade = 8;
+
+module fan() {
+    for (i = [0 : blade]){
+        rotate( i * 360/blade, [0, 0, 1])
+        b_curve([[0, 0], [20, 30], [10, 45], [0, 37]]);
+    }
+
+    cylinder(h, d = 35);
+}
+
+difference() {
+    fan();
+    cylinder(h, d = 5);
+};