Diamond Faced Rock Sphere Grinding Cups

One of the worst parts about grinding rock spheres is the tremendous grit mess.  The solution is diamond faced cups that require only water not grit to work.  10th of the mess and they cut 2x as fast.  Now we have experimented making them by cupping 4 inch diamond facing wheels but by far the simplest, most durable and cost effective method has been brazing with diamond rod.