Added generic_airplane(), show_transform_list()

examples/spring_handle.scad

@@ -0,0 +1,45 @@
+include <BOSL2/std.scad>
+
+$fn = 45;
+wire_d = 2;
+spring_l = 100;
+spring_d = 20;
+rod_d = 10;
+loops = 17;
+tight_loops=3;
+
+tpart = tight_loops/loops;
+lpart = wire_d * tight_loops / 100;
+r_table = [
+    [0.00, 0],
+    [0+tpart, 0],
+    [0.5, 1],
+    [1-tpart, 0],
+    [1.00, 0],
+];
+l_table = [
+    [0.00, -0.50],
+    [0+tpart, -0.5+lpart],
+    [1-tpart, +0.5-lpart],
+    [1.00, +0.50],
+];
+lsteps = 45;
+tsteps = loops * lsteps;
+path = [
+    for (i = [0:1:tsteps])
+    let(
+        u = i / tsteps,
+        a = u * 360 * loops,
+        r = lookup(u, r_table) * spring_d/2 + wire_d/2 + rod_d/2,
+        z = lookup(u, l_table) * spring_l,
+        pt = [r*cos(a), r*sin(a), z]
+    ) pt
+];
+yrot(90) {
+    color("lightblue")
+        path_sweep(circle(d=wire_d), path);
+    cylinder(d=rod_d, h=spring_l+10, center=true);
+}
+
+
+// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap