Create v1, scad, objects hierarchy

v1/scad/lib/extension_twist.scad

@@ -0,0 +1,30 @@
+use <spoolmount_twist.scad>
+
+module extension_twist(h, twist) {
+    assert(h >= 10, "minimum extension height is 10");
+
+    // Bottom spoolmount twist
+    spoolmount_twist();
+
+    // Top spoolmount twist
+    translate([0, 0, h])
+    rotate([180, 0, twist])
+    spoolmount_twist();
+
+    difference() {
+        union() {
+            // Outer body cylinder
+            translate([0, 0, 4.5])
+            cylinder(h=h - 9, r=25, $fn=200);
+
+            // Inner body cylinder
+            translate([0, 0, 2.5])
+            cylinder(h=h - 5, r=23, $fn=200);
+        }
+
+        // Inner through cutout
+        cylinder(h=h, r=16.25, $fn=200);
+    }
+}
+
+extension_twist(h=25, twist=30);