A small semi-automatic cobblestone generator: lava and water make new stone in a 2 × 5 lane while a piston clock pushes you left and right, so holding the attack button mines both columns. Drops you do not pick up end in a chest.
This design works in Minecraft Java 1.20+.
You need 12 kinds of materials (85 items, about 21 inventory slots) — see the shopping list.
Before this layer
Dig a small pit into flat ground: 2 blocks wide and 5 long for the generator, with the redstone room below and in front of it (see the plan). The grey blocks in the 3D view are the natural ground around it.
Blocks on this layer tap a name to find it in the plan
What to do here in the guide's order
Below the front of the generator, build the clock: a loop of repeaters and redstone dust with a button (see the plan for the repeater delays), two redstone wall torches under the two pistons and the two pistons themselves, facing each other on both sides of your standing spot. Two levers next to the pistons stop the machine: with the levers on, both pistons stay out.
Dig a small pit into flat ground: 2 blocks wide and 5 long for the generator, with the redstone room below and in front of it (see the plan). The grey blocks in the 3D view are the natural ground around it.
Place a double chest at the front end of the pit. Behind it, two rows of five hoppers: the first pair points down into the chest, the others point towards the chest (south). Anything you mine that you do not pick up falls into the hoppers.
On 2 layers: Y +1, Y +2
Put a row of 5 stone bricks on both sides of the hoppers, and the same again two blocks higher – they hold the water and the lava. Two more stone bricks close the top at the front.
Stone Bricks×22On 2 layers: Y +2, Y +4
Place open trapdoors around the generator as in the plan (they keep the water in its two channels). At the front, at head height, two trapdoors on the top half, closed: you will stand under them, so you cannot jump while the pistons move you.
On 2 layers: Y +3, Y +4
Fill both side channels with water sources (2 buckets: make an infinite water source). Then pour one lava bucket into the middle of the top row between the upper stone bricks. The lava flows along the top and down onto the hoppers' level, and where it touches the water it turns into stone – the 10 blocks you mine.
On 2 layers: Y +3, Y +4
Below the front of the generator, build the clock: a loop of repeaters and redstone dust with a button (see the plan for the repeater delays), two redstone wall torches under the two pistons and the two pistons themselves, facing each other on both sides of your standing spot. Two levers next to the pistons stop the machine: with the levers on, both pistons stay out.
On 2 layers: Y 0, Y +2
Turn both levers off and press the button once – the pistons now push you left and right every few seconds. Stand in the 1-block gap between the pistons, look at the generator and hold the attack button (an Efficiency V pickaxe makes it much faster; a Haste II beacon even more). The pistons move your aim across both columns while the lava makes new stone.
Without Silk Touch you get cobblestone; with Silk Touch you get stone.
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Tick what you have gathered — it is remembered together with your build progress. A stack is 64 items (signs 16; buckets, beds and boats do not stack); a shulker box holds 27 stacks.
Shulkercraft's video names Minecraft 1.20+ and his comparison video (2026) lists it for 1.21+ and 26.1; the world we built it from is from 1.21.10. Cobblestone generators and piston clocks work the same in all of these versions. We tested 1.21.11 and 26.3.
Our test player stands in the gap, looks straight at the lane and holds the attack button with an Efficiency V netherite pickaxe (no beacon); we count what reaches the chest. Your rate depends on your pickaxe, a Haste beacon and how you aim.
~2,362 Cobblestone/h — Measured on 26.3 (Nov 4, 2026). Measured with our automated test on a local Minecraft server (fake player at the AFK spot); your rate depends on render distance, difficulty and surroundings.
Download the original The schematic / world is offered by the creator or the tutorial author — we link to the original download.
Lava that flows next to water turns into cobblestone. In this generator the lava runs along the top of a lane two blocks wide and five long, with water on both sides: every block you mine is replaced within about a second and a half.
You stand in a one-block gap at the front, under two trapdoors that stop you from jumping. Two pistons on your left and right, driven by a small repeater clock, push you back and forth, so while you hold the attack button your aim moves over both columns of the lane. Anything you do not pick up falls onto hoppers under the lane and into a double chest.
It is not an AFK farm – you have to hold the attack button (with Silk Touch you get stone instead of cobblestone). Shulkercraft's version with a Haste II beacon is even faster.
