
Your next castle needs a mountain of cobblestone. Your pickaxe would like to file a complaint. Meet a compact generator that turns water and lava into a steady supply of building blocks—without the outdoor lava puddle.
2 reusable buckets / 9 storage slots / 576 cobblestone
No fuel bill. No constant refilling. Just room for your next ridiculous building project.
Get the rocks rolling
- Craft the generator. Gather iron ingots, glass, cobblestone, a piston and redstone. Check the recipe book for the layout.
- Place it and right-click. Put one water bucket and one lava bucket into their matching slots. Both are reusable.
- Give it a redstone signal. A lever keeps production going. The signal must stay on while the machine runs.
- Check its power control. Turn the machine on if its own switch is off, then watch the progress bar.
- Add storage below. Place a chest or hopper directly underneath to receive cobble automatically.
Small machine. Big cobblestone energy.
A steady supply: one cobblestone every two seconds by default. Your world may use a different pace.
Room for nine stacks: nine output slots hold up to 576 cobblestone. Full storage pauses production safely until there is room again.
A workshop with character: twin reservoirs, moving fluids, status lights and a progress bar let you see what is happening. Your rocks have never looked so professional.
Easy collection: cobble moves into storage directly below automatically. Hoppers can also take cobble from the sides, and feed buckets from above or the sides without stealing them back.
A handy redstone extra: connect a comparator to see how full the output storage is.
Rock factory taking a nap?
Waiting? Check that both bucket slots are filled. Water and lava are a team.
Paused? Check the machine’s power switch and its redstone signal. A button only powers it briefly; a lever stays on.
Full? Collect some cobble or make room in the storage below. Nothing is thrown away to squeeze in the next batch.
Nothing changed while you were away? The generator only works while its area is active. It will not keep producing in an unloaded area.
Before you pack up
Your buckets, cobble and machine settings are remembered when you save. Breaking the generator drops its contents separately, so bring enough pocket space. The block itself is not a packed suitcase.
Less mining. More building. Same suspiciously large cobblestone collection.

