Deconstruct Mode

Every printer and fabricator can run in reverse. Select a region and the machine consumes it block by block, banking Filament Units into its docked spools first, then into any Filament Racks reachable over MC3D Cable.

Arming a region

1. Set two corners with the Structure Scanner, exactly like scanning.
2. Sneak-click the machine with the scanner. That hands the selection over as its deconstruct region and flips the machine into Deconstruct Mode.

The region obeys the machine’s own print footprint (by default a Tier 3 printer deconstructs at most 3×3, a Tier 8 fabricator up to 51×51 — each tier’s cap is configurable via maxFootprint) and must be within 64 blocks of the machine. Once armed, the region is outlined in the world as a red wireframe so the hazard zone is always visible.

Two safety rules keep accidents out:

• The first job after arming always needs an explicit Start. Auto mode never fires on a freshly armed region — handing a machine a region can’t start dissolving blocks by surprise, even if Auto was left on from printing. After that one Start, Auto resumes as a standing recycler for the region (anything later placed inside gets consumed too — the wireframe is your reminder).
• Re-arming resets the gate. A new region, or toggling Print↔Deconstruct, cancels the job and requires a fresh Start.

Deconstruct works on any blocks in the region — it doesn’t matter whether they were printed, scanned, or built by hand. The wireframe plus the manual first Start exist precisely so you always know what’s about to be consumed.

Lossy by design

Deconstructing credits a fraction of each block’s winding value (config deconstruct.yieldFactor, default 50%) at its exact tier. That’s always strictly worse than mining the block and winding it yourself — recycling is a convenience, not a filament source:

• Winder-blacklisted blocks (planks, cactus, bamboo…) are removed at zero credit — the anti-laundering tag holds in both directions.
• Itemless blocks (water, crops, fire) clear for free, mirroring how printing places them for free.
• Unvalued blocks (dragon eggs, strict-mode unknowns) are skipped in place — the machine never destroys something for nothing.
• Containers with items are skipped in place. Empty them first; the machine never deletes or ejects stored items.
• Unbreakable blocks (bedrock) are skipped.

Job behavior

Jobs run top-down (supported blocks come off before their supports), consume RF per block at the machine’s normal rate, and benefit from Speed and RF Efficiency upgrades — but Efficiency modules and resins never boost the yield. Power loss pauses the job without losing progress. When every reachable spool is full, the machine pauses before removing the next block, so recovered filament is never voided. Changing the region or flipping back to Print mode cancels the job cleanly — blocks already recycled stay recycled.