As indicated by the title, this method isn't quick or simple. But when these steps are followed correctly it's very reliable. Before starting, you will need: Actuators, Switch or Lever, Wires, a Bucket of water, a Bucket of lava, any kind of immobile blocks. Recommended: Extendo Grip, a sup-demonite pickaxe Place a double row of actuators in the sand, just about head height (4 and 5 tiles above ground level). Install the switch. Wire them together. Flip the switch. Make a dam on the open side. Pour in one bucket of water (order matters). Pour in one bucket of lava. Flip the switch again. Dig out the row of sand containing the liquids. Obsidian is created (a weak pickaxe will ensure you don't break it, or just be careful). Dig under the Obsidian. Remove dam and mechanisms. You can make a tunnel least 8 tiles long (probably more) with just one bucket of each liquid, so the Extendo Grip is a big help. As you can see in the GIF, the sand above does not fall even one block, but it will be momentarily disturbed, breaking cactus etc.