Moved all the mechanical stuff into a subdirectory

mechanical/gen_parts.scad

@@ -0,0 +1,19 @@
+use <assembly.scad>;
+
+module genpart(id = 0) {
+  if (id <= 0) {
+    echo(str("Children: ", $children));
+  } else {
+    children(id-1);
+  }
+}
+
+genpart(id) {
+  flcorner();
+  frcorner();
+  brcorner();
+  blcorner();
+  ysled_slider(177.8);
+  ysled_slider(177.8);
+  xsled2();
+}