Tutorials/Cobblestone farming/Factory V3 Piston CSG

This quad-pillar generator fits in a 4&times;3 hole, 5 deep with a couple of blocks dug into the layer below that. It produces 4 cobblestone on every fourth piston cycle. by ZirumsHeroTWR... Earliest Known Publication: Jul 6, 2012

Build tips:
 * 1) When planning, consider that the bottom-layer dust is directly below the on/off switch.
 * 2) When building the clock (north row of layers 0 and 1), place the repeater and set it to max before covering the level 0 components.
 * 3) While you are mostly working from the bottom up, you'll want to finish the switch column early.  This includes a sticky piston facing down; to place this, it help to place at least the output block on level 5, then work down from there.
 * 4) Go up to the surface to flip the lever twice.  This will pick up the switch block, turning off the clock before you place the pistons.
 * 5) Then finish the north wall and continue building in 3&times;3.  The cobblestone need not be placed, any blocks placed there will go up with the blocks above them.
 * 6) Place water first. then lava.
 * 7) Place any height limiters you want for the four columns, and fill the middle column with some non-pickaxe block -- sand, gravel, or wood will do fine.  That's just so your loot doesn't get stranded between the columns.
 * 8) Then turn it on long enough to push up the spare blocks above the cobblestone, and mine those.  Your factory is now running!