Overview
What you are building: A lumber stand with a drop-in cutting-bed cassette. Out of the box the bed holds 8 aluminum honeycomb tiles (laser-ready across the full work area). You also get a full 8-tile MDF spoil set with ¼-20 inserts to swap in for CNC. Fire pan, wear sheet, and under-bed exhaust (Path A) are required — not upgrades.
Not in this first model: perimeter T-track, starter fillers, staged tile buys. Cooler sits beside the stand (reserve extra width). Keep a sheet aisle on one long side if you can.
Why this design
- Torsion-box deck — Two ¾" skins sandwich a 2×4-on-edge core for a stiff, flat table without steel. Feet and pads land on ribs, spine, and blocking — never mid-skin over empty air.
- Apron + short legs — 2×6 apron takes the leg bolts; six 4×4s stop under the apron so the deck skin stays clean. Two full-height end panels kill racking.
- Butt-to-spine ribs — Cross ribs meet a continuous center spine for a solid pad land down the length; ordinary butts and glue — no half-laps required for FIRST MODEL.
- Seam strips in bays only — Skin backing strips sit only in open bays, clear of rims/ribs/spine, so framing still bears on the skin.
- Drop-in cassette — Aluminum frame with ledgers, pan, wear, and exhaust pads onto stand ribs so you can service fire/exhaust without rebuilding the lumber deck.
- Path A required — See Why Path A below. Sealed pan with nowhere for smoke to go is a fail.
Why Path A
Why Path A: Laser cuts drop ash and smoke under the tiles. The fire pan catches them; the plenum (side/front channel outside the tile field) pulls that air out. A sealed pan with nowhere to go is a fail — Path A is required, not an upgrade.
Path A is the under-bed exhaust path: slots in/near the fire pan that open into a plenum (a shallow metal channel on the side and/or front of the cassette), then out toward the enclosure exhaust takeoff.
| Piece | Shop name | Job |
|---|---|---|
| S | Fire pan (0.063" Al) | Catches sparks/ash under the full 49×100" field |
| T | Wear sheet | Sacrificial layer over the pan; leave gaps at the plenum edge so air can enter the channel |
| U | Plenum (Path A) | Side/front channel outside the tile field — slots above ash level, duct toward exhaust |
Build rules
- Mark plenum slot locations on the pan before final install.
- Wear sheet must not tape shut the plenum edge — leave intentional gaps.
- Plenum sits outside the honeycomb (not under the tiles).
- Smoke-test with incense or tissue before calling the bed ventilated.
- Connect duct when the enclosure exhaust takeoff is known (Specs still open on exact takeoff — Overview Q5).
Forbidden
- Pan alone with no slots / no duct (“looks sealed, must be fine”)
- Wear sheet covering the entire plenum lip
- Plenum buried under honeycomb
- Claiming “ventilated” without a smoke-test
Duct takeoff XY still Specs TBD — leave hose length flexible.
How to read fastener labels
Interactive blowout labels use one line:
Name · Fn · from→into
- Name — what to grab (Screw, Lag, Carriage, Glue, …)
- Fn — size family (F1 skin #8×1¼–1½", F2 structural 2½–3½", F5 lag ⅜×3", G1 glue, …)
- from→into — which part into which part (
J→C= apron into a rib)
Example: Lag · F5 · J→C = ⅜×3" lag from the apron into a rib.
Sidebar Hardware lines lead with the plain name and size; the F-code is optional at the end.
Hardware legend
Specs IDs F1–F9 + G1. Blowout label: Name · Fn · from→into (e.g. Lag · F5 · J→C).
| ID | Family | Typical size | From → into | Notes |
|---|---|---|---|---|
| F1 | Skin / splice screws | #8 × 1¼–1½" | H→G, H→F, F/G→C/D/E, light plywood | Always with wood glue on skin & splice joints |
| F2 | Structural wood screws | 2½–3½" GRK/SPAX | 2×→2× (A↔B, C↔A, C↔D), framing into framing | Prefer structural where carriage not required |
| F3 | Carriage bolts (short) | ⅜ × 3½" + washer + nut | Through-bolted apron/leg interfaces | Drill clearance; square neck seats in wood |
| F4 | Carriage bolts (long) | ⅜ × 5" + washer + nut | Thicker stacks (e.g. J+L into K) | Same family as F3, longer grip |
| F5 | Lag screws | ⅜ × 3" | Apron J → C/D/E | Must bite ribs/spine/blocks — not skin-only |
| F6 | Cassette frame hardware | 8020 T-nuts / brackets / M-series | R perimeter; V ledgers to R | Follow 8020 kit; keep metal out of beam path |
| F7 | Pan / plenum metal | Rivets + high-temp silicone | S seams; U channel joints | Not wood screws into pan as primary seal |
| F8 | Leveler hardware | ½"-13 leveler into T-nut in N | N→K bottom; jam nut | 1000 lb swivel; set mid-travel at build |
| F9 | CNC spoil inserts | ¼-20 threaded inserts | Into spoil tiles X @ ~3" o.c. | Clamp studs — laser mode uses HC W |
| G1 | Glue line (wipe) | Wood glue / construction adhesive | Skin butts, splice H, framing butts | Marker = glue line, not a bolt head |
- Skin on wood framing → glue + skin screw (F1)
- Two 2× faces → glue + structural screw (F2) (or carriage)
- Apron into ribs → lag (F5) (or long structural)
- Legs under apron → carriage through J + L into K (F3/F4)
- Aluminum cassette → kit / T-nuts (F6) — don’t lag wood screws into tube as the primary joint
#8 × 1¼–1½" — skins & splice (+ glue) · 2½–3½" structural — lumber-to-lumber · ⅜" carriage 3½"/5" — apron/leg stacks · ⅜×3" lags — apron into C/D/E only · 8020 kit — cassette · Rivets + HT silicone — pan & Path A · ½"-13 + T-nut — levelers · ¼-20 inserts — CNC spoil · Glue — required with F1 and framing butts as scheduled
Locked dimensions
| Stand deck | 111" L × 61" W; top 33" AFF |
| Short cuts between longs | 58" (= 61 − 2×1.5). Never 57 / 60 |
| Work area | 49" × 100" |
| Tiles | 24.5" × 25" · 2×4 grid · 8 HC + 8 spoil |
| Legs | 6 × 4×4 under apron (~19¼" if leveler mid = 2.50") |
| End panels | 2 full-height · ~61" W × 33" H flush outside |
| Fire pan | 0.063" aluminum |
| Design load | 900 lb service |
| Floor | Concrete slab (wood joists → stop and re-review) |
Leg stack: leveler mid 2.50" + plate 0.75" + leg cut + apron 5.50" + torsion 5.00" = 33.00". So leg cut = 19.25" when mid = 2.50". Dry-stack before cutting 4×4s. If mid = 3.0" → cut 18.75".
Package totals
| Stand | ~$1,285 |
| Cassette + fire + Path A | ~$750–780 |
| 8 HC + 8 spoil + inserts + clamps | ~$785–1,065 |
| FIRST MODEL TOTAL | ≈ $2,800–3,500 |
DIY time: stand 2–4 weekends; cassette 1–2; Z + spoil about a day.
Build phases
| Phase | Steps | What you get |
|---|---|---|
| A — Torsion deck | S01–S10 | Closed 111×61 box ~5" thick |
| B — Stand under the box | S11–S19 | Apron, six legs, stretchers, braces, end panels, leveled deck |
| C — Cassette + fire + exhaust | S20–S26 | Drop-in bed frame, pan, wear, Path A |
| D — Z gate | (inside S29) | Measured stack height — cut spoil after real Z |
| E — Tiles | S27–S29 | 8 HC in + 8 spoil cut beside |
| F — Machine | S30 | Enclosure on stand; cooler beside |
Hard gates: (1) Dry-stack legs to 33" AFF before final 4×4 cuts. (2) Confirm apron fasteners bite ribs / spine / blocks — not skin alone — before hanging legs. (3) Measure Z before cutting spoil. (4) Smoke-test Path A before first laser job. (5) Concrete slab only unless Lead re-reviews.
┌─────────────────────────────────────────────────────────────┐ │ ACMER X1 Ultra (~109.4" L × 59.8" W × 16" H) Z │ ├─────────────────────────────────────────────────────────────┤ │ CUTTING BED 49×100 · 8× HC W · spoil swap X · pan S/T/U │ ├─────────────────────────────────────────────────────────────┤ │ STAND DECK torsion 111×61 × ~5.0" · 33" AFF F/G │ │ Apron J + six legs K under apron + two end panels O │ └─────────────────────────────────────────────────────────────┘ Cooler BESIDE (+18–24" width) · ≥48" sheet aisle
Success checklist
- Deck level 32–34" AFF; jam nuts locked
- Two full-height end panels + ≥4 diagonals; six legs under apron
- Machine feet on ribs/spine + neoprene
- Cassette pads (≥6) on ribs/spine
- 0.063" pan + wear sheet + Path A smoke-tested
- Z measured; 8 spoil tiles cut after measure
- 8 honeycomb tiles covering full 49×100"
- Cooler beside; aisle clear
Still confirm (not shop blockers to start buying lumber)
Escalate answers to Specs / Feasibility — do not invent numbers.
| Q1 | Exact leveler mid-travel on purchased feet? (locks 4×4 cut — 19.25" assumes 2.50" mid) |
| Q2 | Real Ultra foot pattern (pad XY)? (final E pad-blocking under feet) |
| Q3 | Ultra operating / shipping weight? (stand + machine + bed ≤ 900 lb service) |
| Q4 | Bed jack / mount hole pattern? (final jack layout on cassette) |
| Q5 | Enclosure door swing + Path A duct takeoff? (clearances / exhaust plumbing) |
| Q6 | Cooler actual W × D × H? (beside clearance; +18–24" width reserved) |
| Q7 | Confirm floor is concrete slab? (joist floors need re-review) |
| Q8 | Short stretcher finished length single-source? (~53.9" clear under current K) |
| Q9 | Enclosure on 61" deck side margin (~0.6"/side) OK in shop? |
Resolved (do not reopen): deck 61" / shorts 58"; end panels ~61×33 flush outside; H = dry-fit F → mark → underside bay strips → reinstall; cassette stack pads→jacks→frame→ledgers→pan→wear→plenum→tiles; buy 10 ft stock for any cut ≥97".
Design — stack diagram
Leg stack-up → 33" AFF
| Layer | Thickness |
|---|---|
| Leveler M (mid-travel) | 2.50" |
| Leg bottom plate N | 0.75" |
| 4×4 leg cut length K | L_leg |
| Apron J 2×6 face | 5.50" |
| Torsion box total | 5.00" |
| Sum | 33.00" |
L_leg = 33 − (2.50 + 0.75 + 5.50 + 5.00) = 19.25"
Dry-stack before final cut. If leveler mid = 3.0" → L_leg = 18.75".
Geometry locks (do not drift)
- Deck 111" L × 61" W — short rims/apron cut 58" (= 61 − 2×1.5). Never 57/60.
- Torsion joinery: continuous spine D ×1 @ 108" + cross ribs C ×20 @ ~28.25" butting into D (and A). Half-lap full C×D optional alt only.
- Splice H bay segments along seams on inside of G / under F, inset ~58" inside A — clear of A/B/C/D; not coplanar with skins. Framing bears on G (3D bay-only H to avoid embed).
- Legs K ×6 under apron: corners ±53.75×±28.75; mids x=0,z=±28.75 (never float inset / never to deck top).
- End panels O ×2 full height (~33 × 61" flush).
- Work field 49 × 100; tiles 24.5 × 25 in 2×4; HC W×8; spoil X×8.
Parts & cut list
Every lettered row matches locked PARTS-LEXICON.md. Click a letter to jump to 3D and highlight that part.
Build steps
Same letters as 3D Assembly. Click a letter chip to highlight in 3D.
Step
Parts this step
Tap a letter for in-viewer detail. Dedicated part pages (/x1/parts/A) are coming — for now use #part-A anchors on the Parts tab.