The recipe
Cobblestone → Gravel → Sand. Crushing lets you make both materials from your generator. The block changes where it stands; the press does not spit out an extra item.
Build a dripstone press
- Place a piston facing up, with cobblestone immediately above it.
- Place a pointed dripstone tip directly above the cobblestone, pointing down towards it. Support the dripstone from above.
- Power the piston once. The cobblestone becomes gravel and the dripstone stays intact.
- Turn the power off before the next pulse. Press again to turn the gravel into sand.
- Mine the sand before another press. Sand does not have another crushing recipe.
You can also reverse the arrangement: a downward piston pushes a block towards an upward dripstone tip. A horizontal piston will not work because pointed dripstone only points up or down.
Use a falling anvil
An anvil landing on cobblestone or gravel performs the same conversion. It can wear down when it lands, so the piston press is the reusable option.