Mega Smelter

Five furnaces in one block, three tiers deep, and a slot that holds a million items.

Mega Smelter smelts five items at once on five independent lanes. Each tier drops a restriction: the second stops needing fuel, the third runs fifty times faster and can reach into the chests around it and feed itself.

Vanilla furnaces are left completely alone.

Requirements

• Minecraft 1.20.1
• Fabric Loader 0.16.10 or newer
• Fabric API
• Java 17

Applied Energistics 2 is optional; if it is installed, its storage is available to the third tier as well.

The three tiers

All three have five inputs and five outputs. The first tier shares a single fuel slot across all five lanes: each lane that is actually cooking spends one tick of burn time per tick, so five busy lanes drink fuel five times as fast. It is five furnaces in one housing, not free speed.

The fuel slot and its flame are removed entirely from the fuel-free tiers, and those tiers refuse fuel from hoppers rather than swallowing coal that would do nothing.

Crafting

Mega Smelter

iron ingot   iron ingot   iron ingot
furnace      diamond      furnace
furnace      furnace      furnace

Mega Smelter II

magma block   magma block    magma block
redstone      Mega Smelter   redstone
ender pearl   chest          ender pearl

Mega Smelter III

blaze rod     nether star       blaze rod
ender pearl   Mega Smelter II   ender pearl
netherite     netherite         netherite

A million items per slot

Every slot holds up to 1,000,000 items, and this works on its own — no stack size mod required.

Vanilla stores an item count in a single byte, which stops at 127. The block therefore writes its own inventory NBT with integer counts, and sends the screen the real numbers over its own packet, because screen handler properties are shorts and stop at 32767. Counts above 999 are drawn as 1.2k, 340k, 1.0M so a full slot does not spill across the window.

If you also run a stack size mod, everything simply works everywhere. Without one, ordinary hoppers are still limited by vanilla's own per-item cap; shift clicking and the third tier's automation are not.

The storage browser

The third tier opens with a panel listing the containers around it.

• Browse every nearby container and click one to look inside.
• Choose the radius, up to 100 blocks.
• Mark containers as sources, and the smelter pulls anything smeltable out of them.
• Mark one as the receiver, and finished goods are pushed back into it.

Scanning walks the block entities of loaded chunks rather than testing millions of positions, and only runs when you open the screen or ask it to refresh.

Access is checked properly. A container only appears if you could open it yourself: spawn protection is honoured, claim and protection mods get a say through a use probe and a dedicated event hook, and any failure in that chain denies access rather than granting it. Assigning a role is validated against a server-side scan performed for that player, so a modified client cannot point the smelter at a chest it was never shown. Every request is rate limited.

Everything else

• Smelts anything with a furnace recipe: ores, food, logs into charcoal, sand into glass.
• Experience accumulates and is handed over when you take from an output.
• Hoppers: inputs from above, fuel from the sides, outputs from below.
• Comparators read the block.
• The block glows and smokes from its front while it works.
• All three tiers share one silhouette — five vents in front, five chimneys on top — in steel, magma and netherite.

Built-in check

/megasmelter

Builds a real smelter, runs all five lanes, and verifies slot layout, fuel-free tiers, the 50× speed, comparator output, storage automation, receiver handling, and that a million item stack and the storage settings both survive being saved and reloaded.

Notes

• The interface has no recipe book button.
• Only furnace recipes are used; the faster smoker and blast furnace recipe sets are not consulted.

License

All Rights Reserved