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Ch 06Before you start

Before you start Chapter 06

Before you start · Chapter 06 — Z axis (and Chapter 06b — Gantry squaring)

Hangs the finished gantry on the four Z joints, belts all four Z corners, and gets the gantry roughly square to the frame — after which the machine can move in Z. Part B (Ch 06b) is the real gantry squaring and cannot be done here: it needs motor control, so it runs out of the middle of Chapter 13 (Step 13.34), cold; the hot lock-in is Ch 14's.

What you're building in this chapter. Four Z joints — one at each corner of the gantry — and the four Z belts that hang the gantry from them. A Z joint is a pair of printed blocks: the z_joint_lower bolts to the ball-bearing carriage riding the Z rail on an upright, the z_joint_upper (the Z bearing block) bolts under the gantry corner, a front idler or A/B drive, and clamps the belt's first end beneath it, and one M5×40 bolt joins the two. The belt's second end clamps on top of the same corner, under the blue upper clip fitted in Ch 05. Each corner's belt runs from that joint down to the Z drive at the bottom of the upright, around its pulley, up to the Z idler at the top, and back to the joint — so turning one drive raises one corner, and four of them together lift and level the gantry. Part A gets all of that built, the gantry lifted into the frame, and the machine roughly square. Part B is the real squaring, and it needs a running printer, so it runs from inside Ch 13 (Step 13.34) — cold and with the machine open. The heat soak and the hot lock-in follow in Ch 14, once the panels are on.

Revali reading a caliper
Four corners agreeing on one height. Get this right and every print remembers it.

Time: 3.5–5.0 h hands-on for Part A, first build (survey §7.2). Part B adds ~1 h hands-on, cold (the heat soak and hot lock-in now live in Ch 14).

Sessions: 9 × ~30 min (first-build estimate — 8 in Part A, 1 in Part B, which is deliberately unbroken; each Pause: line carries its own segment minutes).

Prerequisites:

  • Ch 02 — Z drives, Z idlers, Z rails, deck. Four Z drives built and bolted in, four Z idlers at the tops of the uprights, four MGN9 Z rails on the uprights with their carriages on, 16T/20T pulley stack verified, set screws threadlocked (survey §5.2 W12). The deck panel is in.
  • Ch 05 — Gantry. Complete gantry: X and Y extrusions, XY joints, X carriage, titanium backers already fitted (survey §5.2 W2 — backers after this point means a teardown). Left off the printer, as the manual leaves it at p.106–107.
  • Print batch B05 — Z joints + Z chain (docs/voron-print-plan.md §3 B05). Black ASA, 1 plate, 6.4 h.
  • Print batch B02 — the single blue accent session, which carries the four lower Z belt clips and the Z chain retainer brackets. The four upper clips went on in Ch 05 (Steps 05.19–05.23).
  • Heat-set inserts already done for every part in both batches (survey §5.2 W3).

Tools

  • Hex 2.5 mm, 3 mm and 4 mm; a ball-end 4 mm helps at the Z joints
  • Hex 2.5 mm, 3 mm and 4 mm for Part B
  • Two people for the gantry lift (survey §7.3, chapter 06 row) — Alex on one side, daughter on the other
  • Four rubber rail stoppers taken off the Z rails (the LDO trick, below), or long zip ties as the fallback
  • Needle-nose pliers or tweezers for belt routing (manual p.118)
  • Steel rule / tape for cutting belt; flush cutters
  • Part B only: 150 mm machinist square (DIN 875/2), digital caliper, 150 mm rule, phone with Spectroid (Android) / Sound Spectrum Analysis (iOS) / Gates Carbon Drive

Consumables: small zip ties ×4 (belt tails), long zip ties ×4 (only if you skip the rail-stopper trick), masking tape and marker.

Printed parts

Parts arrive in the bins named below (see the bin map in print/README.md#bins); check the bin label's list before you start.

Looks like STL Bin Repo path Qty Colour Batch
z_joint_lower_x4.stl 06-Z-joints Voron-2 STLs/Gantry/Z_Joints/ 4 Black B05
z_joint_upper_x4.stl 06-Z-joints Voron-2 STLs/Gantry/Z_Joints/ 4 Black B05
[a]_z_belt_clip_lower_x4.stl 06-Z-joints Voron-2 STLs/Gantry/ 4 Blue B02
[a]_z_belt_clip_upper_x4.stl 05-XY Voron-2 STLs/Gantry/ 4 Blue B02 — fitted in Ch 05 (p.91, p.93, p.95); loaded at Step 06.20
z_chain_bottom_anchor.stl 10-chains Voron-2 STLs/Gantry/ 1 Black B05 — fitted in Ch 10 (manual p.201–203)
z_chain_guide.stl 10-chains Voron-2 STLs/Gantry/ 1 Black B05 — fitted in Ch 10 (manual p.201–203)
[a]_z_chain_retainer_bracket_x2.stl 10-chains Voron-2 STLs/Gantry/AB_Drive_Units/ 2 Blue B02 — fitted in Ch 10 (manual p.204)
z_rail_stop_x4.stl 02-Z0 · 02-Z1 · 02-Z2 · 02-Z3 LDOVoron2 STLs/ 4 Black B05 — optional rail-end safety stop, fitted at Step 02.10
— z_joint_upper_hall_effect.stl — Voron-2 STLs/Gantry/Z_Joints/ 0 — SKIP per LDO — no hall-effect endstops in this kit, not printed

Hardware (chapter totals — Part A)

Fastener / part Qty Note
M5 hex nut 4 one per Z bearing block, manual p.110
M3×30 SHCS 4 one per corner; passes through block → lower clip → front idler or A/B drive → the reserved rail-slot T-nut (Step 05.14), p.111
M5×30 BHCS 4 one per corner, same stack, p.111. The second belt end clamps under the Ch 05 M5×16 pair instead
M3×20 SHCS 16 four per z_joint_lower into the MGN9 carriage, p.115
M5×40 SHCS 4 one per Z joint, up from the lower joint into the block's M5 nut, p.115
Gates open belt, 2GT, 9 mm 4 × ~1400 mm (manual minimum ≥1200 mm) manual p.111 minimum for the 350; the kit ships 6 m of 9 mm belt, so 4 × 1400 mm leaves ~400 mm spare for a mis-cut (LDO 350 Rev D BOM)
6×3 mm magnet 0 hall-effect option only — not used
Zip tie, 3×150 mm (belt tails) 4 manual p.120
Zip tie, long (gantry support) 0–4 only if you skip the rubber-rail-stopper trick
Rubber rail stopper — from the Z rails 4 taken off the Z rails and re-fitted mid-rail — LDO note p.114–116

Read first

  • Do manual p.115–116 before p.114. LDO: "We recommend completing steps on page 115-116 then use the rubber rail stopper under the Z joints mid rail. This will allow you to set the Gantry on page 114 on the joints without the need for long zipties." Fit the four lower Z joints and park them at a known height first, then lower the gantry onto them. src
  • Ignore every hall-effect option on p.110 and p.113. LDO note p.145: "SKIP The kit does not use hall effect endstops." Four plain z_joint_upper_x4, no 6×3 magnets, no z_joint_upper_hall_effect.stl. The XY endstop on this kit is the D2F PCB pod fitted in Ch 05. src
  • The gantry lift is a two-person step and the manual says so (p.114: "An extra pair of hands helps with this step"). Nobody holds a 350 gantry one-handed while fishing for an M5×40.
  • The gantry alignment on p.122 is not the gantry squaring. p.122 gets the gantry square enough to belt. The real procedure (Part B) starts by fully releasing A/B belt tension and dropping the lower Z joints, so it has to come after firmware is up. Ch 07's A/B tension is provisional, and so is Part B's (survey §5.2 W1, §4.4 #2). A/B tension is set three times on purpose: Ch 07 (provisional — enough to home and QGL), Ch 06b Step 06b.15 (provisional again, after squaring, machine cold and open) and Ch 14 Step 14.4 (final — panels on, machine cold, door open, immediately before the closed-chamber soak and hot Z-joint tighten of Step 14.6). Z belts: Ch 06b Step 06b.3 (so QGL converges for squaring), set for the last time at Ch 14 Step 14.5, in the same cold session.
  • Belt tension targets: Z belts 140 Hz over a 150 mm span measured from the Z idler centres; A/B belts 110 Hz over a 150 mm span. Both from docs.vorondesign.com. voronldo.com's 80–100 Hz (A/B) and 110–130 Hz (Z) numbers are discarded — survey §4.3.
  • A Z carriage that runs off the end of its rail is a ruined carriage. The balls fall out. Keep the printed z_rail_stop_x4 (batch B05) at the top of each rail, or keep a hand on the carriage.

Sources for this chapter:

Video coverage (Steve Builds, pre-release LDO kit — differs from Rev D+): Part 4 @0:12:41 (+18m), Part 4 @0:55:52 (+32m), Part 4 @1:30:00 (+14m), Part 5 @0:46:00 (+14m), Part 5 @1:03:16 (+10m), Part 6 @1:34:40 (+2m), Part 9 @2:49:00 (+5m)

helperHelper steps: 12 · 06.10, 06.11, 06.12, 06.13, 06.16, 06.20, 06.23, 06.25, 06b.3, 06b.8, 06b.11, 06b.15

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