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Voron V2.4 350mm Build Log — Detailed Walkthrough

V2.4 Build Log 30 min read

After building three Voron Tridents and a V0.2, we decided it was time for the flagship — a Voron V2.4 350mm build. This build log documents every phase of the process: frame assembly, flying gantry construction, quad gantry leveling (QGL) setup, belt routing, wiring harness organization, CAN bus configuration, toolhead assembly, and the critical tuning steps that turn a pile of parts into a reliable high-speed printer.

Last updated: May 2025. This is not a condensed guide — it's the full build log with specific measurements, tension specs, part numbers, and tuning results that you can reference for your own V2.4 build. All parts were sourced China-direct through our mini-program at roughly 40% below LDO kit pricing.

Build Overview and BOM

The V2.4 350mm is the largest standard Voron build. It uses a 350mm³ build volume, 4 Z motors (one per corner, flying gantry design), dual MGN9H rails on X and Y, and MGN12H rails on Z. The total part count is around 600 individual components before fasteners.

Build cost breakdown (China-direct):

Equivalent LDO V2.4 350mm kit: ~$1,400-1,600. Savings: ~55%. The China-direct sourcing route takes more research but the savings are undeniable.

Phase 1: Frame Assembly — Squaring Technique

A perfectly square frame is non-negotiable for the V2.4. The flying gantry design means any twist or skew in the frame is amplified through all four Z leadscrews, causing binding, uneven Z travel, and mysterious print defects that are maddening to troubleshoot.

Our method: We used a surface plate approach. We laid two 2040 extrusions parallel with a 350mm gap on a known-flat surface (a granite countertop). We assembled the bottom frame (Y-axis base) upside-down on the flat surface, so gravity worked with us to keep everything coplanar. Screws were loosely threaded first, then progressively tightened in a crossing pattern while checking with a 1m precision straight edge.

Diagonal measurement: After all corner brackets were tightened, we measured the diagonals with digital calipers. A 350mm square frame should have diagonals within 0.5mm of each other. Ours measured 495.2mm and 495.6mm — a 0.4mm difference, well within tolerance.

Vertical alignment: The four 2020 vertical extrusions must be perfectly plumb. We used a 600mm machinist square at each corner. The gap between the square leg and the extrusion was 0.1-0.2mm at the top — acceptable. If the gap exceeds 0.5mm, you'll have binding issues on the Z rails.

Pro tip: Don't use the 2020 extrusion slots as reference surfaces — they have ±0.2mm tolerance from the extrusion process. Instead, use the outer faces which are more consistent. And always deburr before assembly; a 0.1mm burr can throw off alignment by several times that when multiplied by lever arm effects.

Phase 2: Gantry Assembly and Belt Routing

The V2.4 gantry is a complex assembly of two 2040 extrusions (X-Y gantry beams), four MGN9H rail carriages, the XY joint pieces, and the CoreXY belt routing system.

Rail parallelism: Each gantry beam carries two MGN9H rail carriages. Getting the rails parallel is critical. We mounted one rail first, tightened it, then used a gauge block (a 10mm thick piece of ground steel) between the carriages to set the spacing for the second rail. This guarantees both carriages on the same beam are exactly parallel.

XY joints: The XY joints connect the gantry beams at right angles. Use a precision square during assembly. The XY joint screws should be tightened to 1.2 Nm — not more. Overtightening can distort the printed XY joint pieces.

Belt routing — the critical path: The V2.4 uses a standard CoreXY belt pattern. Route A motor (left-front) belt to the left gantry idler, across the back to the right idler, then to A motor. Route B motor belt to the right gantry idler, across to the left idler, then back to B motor. The belts must not cross or rub against each other at any point.

Belt tension measurements: Using the Gates Carbon Drive app (free, iOS/Android):

Gantry movement test: After belt installation, the gantry should move across the full Y range (350mm) with a single finger push. If it binds, check belt routing, rail parallelism, and XY joint alignment. We had to loosen and re-align the XY joint on the right side after initial assembly.

Phase 3: Quad Z-Leveling (QGL) Setup

The QGL system is the most distinct feature of the V2.4. Four Z motors (one at each corner) raise and lower the entire gantry. The goal is to have the gantry perfectly horizontal at all Z heights — no tilt, no twist, no bow.

Leadscrew installation: We used T8 leadscrews (2mm pitch, 4-start = 8mm rotation distance) with flexible shaft couplers. Each leadscrew passes through a leadscrew nut mounted on the gantry corner. The nuts should be snug but not tight — they need a tiny amount of play to self-align.

Motor wiring: The four Z motors must be wired to separate driver channels on the Octopus Pro. We used Z1 through Z4 on the board. The Z endstop is a virtual endstop triggered by the probe touching the bed — there are no physical Z endstops on the V2.4.

QGL configuration in Klipper: The [quad_gantry_level] section requires the gantry corners to be defined:

QGL results after 3 iterations: All four gantry corners within 0.03mm of each other. The system is remarkably precise. Run QGL before every print if you want consistent first layers.

Phase 4: Wiring Harness and CAN Bus

The V2.4's flying gantry requires a cable chain that moves with the gantry (Z axis) and a second chain that moves with the toolhead (X axis). Managing these cables is one of the most tedious but important parts of the build.

Cable chain organization (top to bottom):

CAN bus setup with BTT EBB36: We used the EBB36 v1.1 CAN board on the Stealthburner. Configuration steps:

Wiring tips: Use shielded twisted-pair wire for CAN H/L (Cat5e cable works perfectly). Ferrule all wire ends before inserting into screw terminals. Use heat shrink labels every 100mm on the Z chain wires for easy identification. Leave 10-15% extra length in the chain — the cables settle and compress over time.

Phase 5: Toolhead Wiring and Assembly

We used the Stealthburner with CW2 extruder and Rapido UHF Plus hotend. The EBB36 CAN board mounts directly to the Stealthburner's dedicated mounting holes.

Wire routing through toolhead: The EBB36 connects to: hotend heater (2 wires), hotend thermistor (2 wires), part cooling fans (2x 5015, 2 wires each = 4 wires), heat sink fan (3010, 2 wires), Neopixel LED (3 wires), extruder stepper (4 wires), extruder hall effect sensor (3 wires). That's 20 wires into the EBB36 — manageable with careful routing.

Wire management: We used braided PET cable sleeving on the toolhead wires. Each wire was cut to exact length measured from the EBB36 to the component (±5mm). Excess wire creates a mess inside the toolhead and can interfere with the fan blades.

Phase 6: Klipper Configuration and Tuning

This is where the build comes alive. We used the official Voron V2.4 350mm printer.cfg as a starting point and customized for our specific hardware.

Stepper rotation distance calculations:

PID auto-tuning results:

Input shaper calibration (ADXL345 accelerometer):

Pressure advance calibration: Started at PA=0.04, adjusted to PA=0.038 after the PA tuning tower. The Rapido UHF has very consistent extrusion behavior. The PA value is lower than typical because the CW2's gear engagement is very tight and the Rapido's CHT nozzle pre-melts filament uniformly.

Bed mesh: 7x7 grid with 3 samples per point. Maximum deviation: 0.087mm over the 350mm bed. The 350mm cast aluminum tooling plate is exceptionally flat.

First Print Results

First print: Voron test cube at 0.2mm layer height, 0.4mm nozzle, 120 mm/s, 3,000 mm/s² acceleration. Result: near-perfect. Layer adhesion excellent, dimensional accuracy within 0.05mm, no visible ringing or ghosting. The ZV shaper tuning eliminated the subtle ringing we saw on our initial square-corner test.

Speed test: We pushed up to 300 mm/s with 0.6mm nozzle at 0.28mm layer height. The Rapido UHF handled the flow without issue. Surface quality at 200 mm/s was indistinguishable from 60 mm/s — the input shaper tuning was working perfectly.

Material tests: PLA, PETG, ABS, and PC all printed successfully. ABS required a 60-minute chamber preheat to stabilize the enclosure temperature at 55°C. PETG needed reduced fan speed (30%) to prevent warping. PC required 110°C bed and 285°C hotend — the Rapido handled it easily.

Lessons Learned and Recommendations

The V2.4 350mm is the ultimate Voron build. It's more complex than the Trident, more expensive, and takes longer to build — but the result is a machine that produces exceptional print quality at high speeds across a massive build volume. If you have the patience and budget, it's the printer you keep forever.

Need Help With Your V2.4 Build?

We offer curated V2.4 350mm parts kits at China-direct prices — pre-verified components from trusted factories, with consolidated shipping so everything arrives in one box. Save 40-55% over premium kits without the sourcing headache.

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