Before you start Chapter 01¶
Before you start · Chapter 01 — Frame
Builds the 2020 frame — bottom square, four verticals, top square — plus the two bed extrusions, squared on a verified-flat surface. Unlocks Ch 02 (Z drives) and Ch 03 (build plate), and fixes the squareness every later axis inherits.
What you're building in this chapter: the box the whole printer hangs off, out of 2020 aluminium extrusion — 20 × 20 mm bars with a T-slot down each face, so anything can be bolted anywhere along them. Three sub-assemblies. The bottom square is four horizontal extrusions joined by the four verticals that stand in its corners; the top square is four more horizontals closing the cube at the top. Every one of those sixteen corners is a blind joint — a screw threaded into the end of the horizontal, its head hidden inside the vertical's slot, tightened through a small access hole in the vertical's side. The bed extrusions are two more horizontals running front to back across the base, left and right of centre, carried on corner brackets from the front and rear bottom rails; the heated build plate sits on them in Ch 03, and their spacing has to match the plate's own mounting holes. Everything is assembled loose, squared with a tape measure and a mallet, and only then tightened — because a bolt taken to full torque locks in whatever error was there when you tightened it.
Time: 2.5–4.0 h hands-on, first build, two people (survey §5.1 P01 / §7.2).
Sessions: 4 × ~40 min — the Pause: lines below break the chapter into 4 segments of 25–65 min; every minute figure is a first-build estimate.
Prerequisites:
- Ch 00 — inventory, extrusions counted, tools to hand.
- Print batches: none gate this chapter. No printed part is required for the frame; you can square it the day the kit lands (print plan §2). Nothing is printing underneath it either: all 22 plates, B00 through B10, came off the Prusa before the cartons arrived, so Ch 02 starts the moment this chapter closes.
Tools
- 3 mm hex key, straight, long-arm — the kit's 3 mm L-wrench, if the kit has one (verify on bench); the Fabreeko precision set is ball-end — for the 16 M5×16 BHCS blind joints; the access hole is in line with the bolt, so no ball end is needed and a straight key is better for the torque pass. A 3 mm ball-end is optional for the first snug
- Machinist square, 150 mm, DIN 875/2 or better
- Steel rule 300 mm, plus a steel tape ≥1 m (a 350 frame's plan diagonal is ≈721 mm)
- Straightedge + feeler gauges, 0.02–0.10 mm — to re-check the reference surface (Step 01.1)
- Flat reference surface: the kitchen stone counter, verified (decision: Ch 00 Step 00.10)
- Rubber or nylon mallet, for nudging the frame square
- Torque screwdriver 0.5–3 N·m — optional; the manual specifies no torque value
- Masking tape + marker (FRONT label, extrusion labels, log)
Printed parts
| STL | Qty | Colour |
|---|---|---|
| none — this chapter needs no printed parts | — | — |
Hardware (chapter totals)
| Fastener / part | Qty | Where |
|---|---|---|
| A extrusion | 10 | 4 bottom + 4 top frame (p.15–17), 2 bed (p.18–20) |
| B extrusion | 4 | verticals (p.15–16) |
| M5×16 BHCS | 20 | 16 frame blind joints + 4 corner brackets |
| Corner bracket, 2020 cast — from the kit, no LDO BOM row | 4 | one per bed-extrusion end (p.18); (verify on bench) which box carries them |
| M5×10 BHCS | 4 | bed extrusions down to the frame (p.19) |
| M5 precision spacer, brass | 4 | under each M5×10 head — replaces the manual's "M5 shim" |
| M5 T-nut, roll-in | 4 | bottom rails, under the bed extrusions (p.19) |
C, D and E extrusions are sorted here but not used in this chapter — they are the gantry (manual p.85, p.88, p.101 → Ch 05).
Read first
- Frame squaring is the one irreversible quality decision in this build. Re-check after every tightening pass. Gantry racking, quad-gantry-level and bed mesh all inherit what you set here (survey §4.4 #1).
- Extrusion and roll-in T-nut tolerances are tight in this kit. LDO: "Due to the tight tolerances of the extrusions and roll-in t-nuts it is advisable to either test fit before assembly to identify the sides of the extrusions that fits the best or to pre-load the t-nuts into the extrusions." src
- Every "M5 shim" in the official manual is a brass M5 precision spacer in this kit — here and for the rest of the build.
- Titanium extrusion backers are NOT installed in this chapter. They go onto the gantry's X and Y extrusions during Ch 05, on the face opposite the rail. Leave them bagged; fitting them to frame extrusions now would be wrong and fitting them after the gantry is assembled costs a teardown (survey §4.4 #3, §5.2 W2). This is the only place this note appears.
- Nothing here is printed. Build it the day the kit lands — the printer is idle and every bin is already full.
Sources for this chapter:
- Voron 2.4r2 assembly manual (pinned
de7e89d) pages 12–21 — extrusion sort, blind joints, bottom and top squares, bed extrusions, squareness check - LDO Build Notes (Rev D) — roll-in T-nut tolerance, and the brass M5 precision spacer substituted for every "M5 shim"
- blind-joint video and frame squaring video — the two videos the manual links from p.10 and p.21
- whopping_Voron_mods —
extrusion_backers— why the titanium backers are Ch 05 parts, not frame parts - survey §4.2, §4.4, §5.2
Video coverage (Steve Builds, pre-release LDO kit — differs from Rev D+): Part 1 @0:54:42 (+2m), Part 1 @0:55:46 (+19m), Part 1 @1:14:12 (+14m), Part 1 @1:29:00 (+19m), Part 5 @3:14:50 (+2m)
Helper steps: 13 · 01.1, 01.2, 01.7, 01.8, 01.9, 01.10, 01.12, 01.13, 01.14, 01.15, 01.19, 01.20, 01.22