adding test code for weld nuts and rod ends, adding ball bearings to test code list, and updating code for dome screw heads to use an angle to determine inset distance of the lower taper

tests/nuts.scad

@@ -85,6 +85,13 @@ module nuts() {
             if(n == M8_nut)
                nut_square(M8nS_thin_nut);
        }
+
+       translate([0,150]){
+            if(n==M4_nut)
+                weld_nut(M4_weld_nut);
+            if(n==M6_nut)
+                weld_nut(M6_weld_nut);
+       } 
     }
 }
 

tests/rod_ends.scad

@@ -0,0 +1,17 @@
+
+include <../utils/core/core.scad>
+use <../utils/layout.scad>
+
+include <../vitamins/rod_ends.scad>
+
+
+module do_rod_ends(list) {
+    diameters = [for(b = list) rod_end_bearing_od(b)];
+    max = max(diameters);
+    layout(diameters) let(b = list[$i])
+        //translate([0, (max - bb_diameter(b)) / 2])
+            rod_end_bearing(list[$i]);
+}
+
+if($preview)
+    do_rod_ends(rod_ends);