Space Engineers — Auto Ship-Builder Setup

Layer-by-layer welding rig · X/Y sweep + Z lift · test piece: solid 7×10×4 light-armor block

1 · Front Elevation — the gantry

Welder carriage rides vertical Z-pistons. Projector sits on a seed plate so layer 1 has something real to weld onto. The whole blueprint is projected at once, but only the supported layer can actually weld.

WELDER CARRIAGE (row of welders) SEED PLATE (start block) PROJ layer 4 · locked layer 3 · locked layer 2 · WELDING NOW layer 1 · built Z LIFT · +1 block/layer (2.5 m) X / Y sweep
built (real) active / buildable locked layer frame / pistons
2 · Top-Down — covering the 7×10 footprint

Two reliable ways to cover one layer. LEFT: a full-width welder row (7 wide) sweeping along the long axis — simplest, fewest missed blocks. RIGHT: a single/short welder doing a serpentine (boustrophedon) raster — cheaper but every turn is a chance to miss an edge block and stall the layer.

A · full-width row → single-axis sweep WELDER ROW (7 heads) sweep (one axis) 7 wide × 10 long → one piston axis ✓ full coverage, hard to miss B · short welder → serpentine raster X turns + Y step each row ⚠ edges/corners = stall risk
3 · Weld-zone geometry — "tighten the geometry"

This is about welder placement, not the blueprint. A welder's weld zone is a box (~1.5–2 large blocks). Keep that box centered on the active layer. If it straddles the boundary it bites into the layer above and starts welding it the moment support appears — before your sweep finishes the current pass.

✓ GOOD — zone on one layer built active locked zone hugs active layer · clean pass ✗ BAD — zone straddles boundary reaches 2 layers starts next layer early · messy / uneven
weld zone (good) weld zone (straddling) tip: sit slightly LOW (bite the built layer below) rather than high
4 · Why it self-limits — support rule + pass cycle

A projected block can only weld when it touches a real block. So even though all 4 layers project at once, layer N+1 physically can't build until layer N exists. That's what gives you free layer-by-layer behaviour — no "single layer" projector setting needed.

1 · seed only SEED 2 · L1 welded L2 unlocks 3 · lift + L2 L3 unlocks 4 · …repeat → done 280 blocks ✓ PASS CYCLE weld layer → layer complete → next layer unlocks → Z lift +1 block → weld → … → blueprint done manual = pulse lift · auto = PB/Event Controller watches "Remaining Blocks"
5 · Control wiring — Timer ping-pong + Event Controller

Two timers loop forever: WELD a layer (~6 s), then LIFT exactly one block (velocity × time = 2.5 m). The Event Controller watches piston extension and, at the last layer, freezes the lift and runs one final weld window before shutting down. Fully vanilla — no Programmable Block.

TIMER · T_WELD delay 6 s (= weld time) 1 · WELDERS → Off 2 · LIFT → Velocity +0.5 3 · Start T_STEP TIMER · T_STEP delay 5 s (0.5 m/s × 5 = 2.5 m) 1 · LIFT → Velocity 0 2 · WELDERS → On 3 · Start T_WELD done welding → lift one block lifted → weld next layer START (manual) WELDERS On · Start T_WELD EVENT CTRL · EC_DONE watch LIFT position when extension ≥ 7.5 m → Stop T_STEP · Start T_FINISH LIFT extension (4 layers = 3 lifts) freeze lift TIMER · T_FINISH delay 7 s (one last weld) 1 · WELDERS → Off 2 · Stop T_WELD · alert TUNE TWO NUMBERS weld time = how long a full layer takes · lift time = 2.5 m ÷ piston velocity · keep velocity ≤ 0.5 m/s (anti-Clang)
T_WELD (weld phase) T_STEP (lift phase) Event Controller T_FINISH (shutdown)
6 · Small-grid seed — bridging large rig → small grid

You can't build small-grid blocks directly onto a large grid — they're separate grid systems. Bridge them with a large Advanced Rotor set to a small head, then build the small seed on that head. Power crosses the rotor (projector stays alive, often no battery needed); conveyor/items do NOT cross — feed those through the seed's connector. Small grid pitch = 0.5 m, so the lift step is 0.5 m/layer, not 2.5.

LARGE-GRID RIG 2.5 m blocks · static base · power source Adv. Rotor (large) small head ⚡ power crosses ✓ ⛔ conveyor does NOT SMALL-GRID SEED PROJECTOR battery* CONNECTOR 0.5 m blocks · *battery optional (rotor powers it) locks to PROJECTED ATMO MINER (small grid) ship conn. when done → unlock connector → flies off as its own grid + has a dock port SETUP ORDER place large rotor → attach SMALL head → lock rotor → build seed (projector+connector) on head → aim connector at weld zone → load blueprint (with matching connector)
large grid rotor bridge / small seed connector (clean undock) ⚡ power crosses rotor · ⛔ items don't
7 · Movable welders — why they jam, and the fix

With a fixed seed and a movable welder row, the welders travel THROUGH the build's footprint. Sweeping one layer is fine — but the layer-STEP drives the welder bodies up into cells the solid build just filled → collision (the "welding below the tip / hitting what it welded" jam). Fix: don't step straight up. Retract out, step, extend back — a "peck" cycle. Or keep welders on the perimeter, outside the footprint entirely.

✗ stepping UP through a solid build just welded built Z step ↑ ⚠ body rams welded cell sphere fills cells around body → next layer is where the welder must go = STUCK ✓ peck cycle — retract, step, extend gap 2 · retract out 3 · Z up 1 4 · extend in 1 · weld (sweep X/Y) bodies travel in EMPTY space beside the build — never through welded cells STURDIER: perimeter welder RING — bodies outside the hull profile, build passes through the ring plane. Welders can never be buried, any build height. Best for tall / complex builds.
built active layer collision / weld sphere rule: welder BODIES only move through empty cells

Space Engineers auto-builder reference · made for a solid 7×10×4 test piece · open in any browser