Before you start Chapter 03¶
Before you start · Chapter 03 — Build plate
Prepares the 355×355×10 mm heated plate and bolts it to the bed extrusions, so the frame has its datum surface and the plate's three leads lie loose above the deck, ready for the bed WAGO breakout in Ch 09.
What you're building in this chapter: the heated bed, as a stack of four things. The build plate is a cast, ground aluminium slab with a mains-powered silicone heater pad and a 125 °C thermal fuse already bonded to its underside — both are factory-fitted on this kit, so two of the official manual's pages become inspections. On top of it you laminate the magnetic pad, an adhesive magnetised sheet, and onto that drops the flex plate: removable spring steel, the surface prints actually stick to and the reason you can pop a finished part off by flexing it. The whole stack sits on four thumb-nut spacers on the two bed extrusions from Ch 01, held by four bolts of which only one is ever tightened — the other three let a 355 mm aluminium plate expand as it heats instead of buckling. Nothing is wired here; the plate's three short leads stay loose above the deck, for the bed WAGO breakout Ch 09 fits on the left bed extrusion.
Time: 1.5–2.5 h hands-on, first build (survey §7.2).
Sessions: 4 × ~30 min — the Pause: lines below break the chapter into 4 segments; every minute figure is a first-build estimate.
Prerequisites:
- Ch 01 — Frame. Squared, and the bed extrusions positioned with 65 mm from the centreline to each inner face — a 130 mm clear gap, 150 mm centre-to-centre (manual p.20; Ch 01 Step 01.19).
- Ch 02 — Z drives and idlers. Deck panel and deck supports fitted (manual p.28–29); the wire opening in the deck must be clear and unobstructed.
- Printed parts: none. No print batch gates this chapter. The 2.4r2 mounts the plate straight onto the bed extrusions with metal hardware — there are no printed feet, bed mounts or spacers anywhere in p.52–61. The bed WAGO mount is supplied printed by LDO and is fitted in Ch 09, not here.
Tools
- Hex 2.5 mm
- Plastic scraper, squeegee or an old credit card (magnet application)
- Sharp craft knife with a fresh blade (trimming the magnet at the bolt holes; cutting the liner at Step 03.9)
- Masking tape (marking the back edge at Step 03.2; the hinge for the magnet at Step 03.9)
- Steel rule or straightedge ≥360 mm (flatness check and the 38 mm offset)
- Digital caliper
Consumables: IPA ≥90%, lint-free cloth, nitrile gloves. The plate's protective film goes in the bin.
Printed parts
| STL | Qty | Colour |
|---|---|---|
| — none — | 0 | — |
Hardware (chapter totals)
| Fastener / part | Qty | Note |
|---|---|---|
| Build plate, cast 5083, 355×355×10 mm, heatpad and 125 °C fuse pre-applied | 1 | LDO 350 Rev D BOM |
| Magnetic Pad 2.4-350 | 1 | applied in this chapter |
| Spring Steel Flex Plate 2.4-350 | 1 | drops on, no fasteners |
| M3×20 SHCS | 4 | not the manual's M3×16 |
| M4 knurled thumb nut | 4 | used as the spacer, not as a nut |
| M3 roll-in T-nut, 2020 | 4 | bed extrusion top slots |
| M4×6 BHCS (bed PE) | 0: pre-fitted to the plate | verify only, do not remove (washer: verify on bench) |
Read first
- The heater pad (p.55) and the thermal fuse (p.56) are already on your plate. Both pages are verify-only. Do not peel, re-seat or re-bolt anything. src
- Trim the magnet at the four bolt holes immediately after you roll it down and before you bolt anything. Discovering it at p.59 means peeling the magnet or drilling through it (survey §5.2 W6).
- Use M3×20 SHCS, not the manual's M3×16 — this plate and these spacers are thicker. src
- The magnet goes on with the hinge method at Step 03.9 — one shot; read the whole step before you peel anything.
- Only one of the four bolts gets tightened (p.59). A bed clamped hard at all four corners while cold, then heated fast, tacos.
- A part missing, damaged or wrong: stop, photograph it and ask Fabreeko. Questions about LDO's own parts go to
#ldo_motors. Both are set up at Step 00.31. - No wiring happens here, and no bed lead goes through the deck. Manual p.60 feeds the bed wires through the opening; this kit's plate leads end at the bed WAGO breakout above the deck (Ch 09), and only the kit's extension leads go below, in Ch 10. Leave the three leads loose above the deck. src
Sources for this chapter:
- Voron 2.4r2 assembly manual (pinned
de7e89d) pages 52–61 — plate orientation, magnet, bed-extrusion verification, spacers, the DON'T TIGHTEN rule - LDO Build Notes (Rev D) — p.55 and p.56 skipped (heater and fuse pre-applied), M4×6 PE screw, M3×20 instead of M3×16, trim the magnet now
- LDO 350 Rev D BOM — plate, magnetic pad, flex plate and thermal-fuse line items
- LDO wiring guide § Wiring the Bed Heater — where the three bed cables actually terminate (Ch 10)
- magnet lamination demo — the lamination demo the manual links from p.54
- survey §5.2 W6
- The two mirrored images in this chapter, the plate's underside at Step 03.4 and the build-plate mapping at Steps 03.14 and 03.19, are LDO Motors', used with attribution; see
assets/remote/03-build-plate/SOURCES.txtandassets/remote/10-wiring/SOURCES.txt. Each original URL stays on its step'sSource:line.
Video coverage (Steve Builds, pre-release LDO kit — differs from Rev D+): Part 1 @0:45:02 (+5m)
Helper steps: 8 · 03.2, 03.4, 03.7, 03.8, 03.11, 03.14, 03.16, 03.18