This is my first tutorial teaching you how to make an automatic cobblestone generator.
Step 1: The supplies
This is all that you will need to make the generator.
Step 2: The first wall
First build the wall like it is in the picture.
Step 3: Dig a hole
Dig a small 2 block hole at the back of the wall.
Step 4: Make the hole bigger
Expand the hole and make it 6 blocks long. (6x2)
Make the wall longer to fit the size of the hole.
Step 5: Make a second wall
At the sixth part of the long hole, place two blocks at the end.
Step 6: So far...
This is what it should look like so far.
Step 7: Make a bridge
Make a bride from one side to the other.
Go under and turn the bridge into a hole.
Step 9: Fill the hole with lava
Time to add some fluids to the mix.
Fill the newly created bridge into a hole with two buckets of lava.
Step 10: Just add water...
Place two buckets of water on the two blocks that are high.
The water should begin to flow.
Step 11: Mine the bridge, make cobble!
Mine the bridge you made.
It should be replaced with two pieces of cobblestone.
If it isn't, you did it wrong and should probably start over.
Step 12: Time for redstone
Time to add some redstone.
Mine the stone to the left and make a stone path along the wall.
Step 13: Put a sticky piston
The title says it all.
Put a sticky piston on the new path.
Step 14: Place a redstone repeater
Place redstone on the path like in the picture.
Then place a repeater that is also in the picture.
Step 15: On / Off
Place another stone with a lever and a redstone torch on it.
(Do not use the lever yet!)
Step 16: Loop the redstone
Loop the redstone around like so.
Step 17: Destroy a stone
Destroy the stone parallel (across) from the other stone you destroyed.
Step 18: Start the cycle
Place another redstone next to the repeater.
After a few ticks, it should burn out.
When it does, right click the repeater to fix that.
You should continue to press it to put as many ticks as possible.
Step 19: Flip the lever
The lever should turn the machine on and off.
The cobblestone will continue to make a longer path.