I constructed a 3 dimensional cobblestone generator, that essentially gives a blank slate for carving, or mining. Similar to an artist's marble slab. It takes a little while for the stone to be replaced, however, if you mine while it's running you'd have to spend quite a long time before you demolished it.It's pretty disorganized, I didn't find a perfectly congruent system for the pistons' redstone wiring on the back (which can probably be attributed to my haste), but it's functional, and pleasing to watch in action. I had it complete in a little under an hour.If you'd like cobblestone, meet up with Maizie123. She can probably give you some of her extras from the machine.