Factor out common spoolmount components

lib/spoolmount.scad

@@ -0,0 +1,19 @@
+use <torus.scad>
+
+module spoolmount() {
+    // Ring
+    difference() {
+        cylinder(h=5, r=42, $fn=200);
+
+        translate([0, 0, -1])
+        cylinder(h=7, r=25, $fn=200);
+    }
+
+    // Rounded edges
+    translate([0, 0, 2.5]) {
+        torus(r_major=25, r_minor=2.5, xs=0.7, $fn=200);
+        torus(r_major=42, r_minor=2.5, xs=0.7, $fn=200);
+    }
+}
+
+spoolmount();