Ch 14Before you start

Before you start Chapter 14

Before you start · Chapter 14 — Calibration and tuning

Takes a machine that homes, probes, levels, is squared cold and has printed its first cube (Ch 13), now closed in by Ch 11 Part B, and turns it into a machine that prints Voron-quality ASA: belts at final tension, the gantry's Z joints locked at working temperature, extruder refined, input shaper set, pressure advance and flow dialled in, and that cube calipered against the Prusa-printed reference.

What you're building in this chapter. Nothing mechanical is added; six calibration items are measured and written down. Belt tension is set for the last time, now that gantry squaring has released it — a tensioned belt is a string, and its pitch over a measured span is the reading. Then the closed chamber gets its first real heat soak, QGL is run until it settles, and the four Z joint bolts are given their only full tighten while the frame is at working temperature — the last three steps of Voron's squaring procedure, which Ch 06b left for a panelled machine. The extruder value measured in Ch 13 is re-checked. Input shaping uses the accelerometer built into the toolboard to find the frequency at which this machine rings, fits a filter that cancels it, and brings the acceleration ceiling down from its placeholder. Pressure advance compensates for the lag between the extruder and the nozzle at corners, and extrusion multiplier scales the total amount of plastic — both belong to the filament, not the machine. Between them sits the chamber: how hot the closed enclosure actually gets, which decides both the print profile and the soak time. The tuning log at the end is the deliverable. Part H is an optional add-on: the stock Voron exhaust housing on the back panel, its fan driven by the chamber thermistor, so PLA and PETG print under a 35–40 °C ceiling while ASA keeps its closed chamber.

Here the kit becomes a printer. I brought a caliper. Feelings are not evidence. My opinions nearly are.

Time: 2.5–4.0 h hands-on (survey §7.2), spread over ~8–10 h wall-clock. Most of the wall-clock is the 1½–2 h closed-chamber soak at Step 14.6, the shorter soaks (~30 min each) and four test prints. The optional exhaust add-on (Part H) adds ~3.5 h hands-on, plus ~7 h of Core One+ printing made after its first step passes, a ~1 h chamber soak and a ~1 h PLA print.

Sessions: 14 × ~30 min hands-on, 20 with Part H (one Pause per calibration item; every minute figure is a first-build estimate derived from the Time range and the step count, and excludes soaks and test prints).

Prerequisites:

• Ch 13 — First power-up and initial startup. All wizard steps passed (temperatures → heaters → fans → STEPPER_BUZZ → XY endstop → homing → bed locating → 0,0 → Z endstop → probe → PID → QGL → Z-offset), filament loaded and rotation_distance measured at Step 13.40, the Voron printer profile made at Step 13.41.
• The Voron-printed Voron_Design_Cube_v7 from Ch 13 Steps 13.41–13.42, kept. Ch 13 prints the cube and commits the first-layer squish; this chapter measures it, at step 14.11.
• Ch 06b — Squaring the gantry, cold, run out of the middle of Ch 13 at Step 13.34 and finished before Ch 13's Z=0 and mesh: gantry square, the four Z joint M5×40 bolts reinstalled lightly (06b.13) and not yet torqued, A/B belts at a provisional tension. This chapter's belt-tension steps must come after 06b — the squaring procedure starts by fully releasing A/B tension, so anything you set before it is gone (survey §4.4 #2, §5.2 W1). Voron's squaring steps 14–17 (closed-chamber soak, QGL 3–5×, tighten the Z joints hot, restart) are Step 14.6 here, because they need the panels.
• Ch 11 Part B — Panels and the Clicky-Clack door, on. The chamber has to close: Step 14.6's soak, Step 14.8 and Checkpoint 14 all gate on a closed chamber.
• Ch 12 — Software. [bed_mesh] added at Step 12.34, PRINT_START replaced at Step 12.36 (survey §4.4 #15).
• Batch B00. The Prusa-printed Voron_Design_Cube_v7 in Prusament ASA Galaxy Black, kept as the reference coupon (B00 step B00.6). You need it in hand at step 14.11.
• Printed parts: none for Parts A–G; everything they print, they print on the Voron. Part H prints its own five parts on the Core One+ at Step 14.26, after Step 14.25 has checked the machine.
• Part H only: the Step 00.8 exhaust row (a 24 V 6020 fan, a 1 m JST-XH extension, carbon filter mat), bought after Step 14.25 passes.
• A spool of Prusament ASA in the dryer, warm and loaded (survey §7.3).

Tools

• Digital caliper, 150 mm
• Steel rule, 150 mm minimum (belt spans and the e-step mark)
• Masking tape and a fine marker (e-step mark; Ellis prefers tape to a marker line)
• Phone with a spectrum analyser: Sound Spectrum Analysis (iOS), Spectroid (Android), or Gates Carbon Drive (both — use the "motorcycle" option) src
• Hex 2.5 mm (A/B front tensioners, M3×40; Z idler tensioners, M3×16) and a ball-end hex 4 mm (the four Z joint M5×40 bolts, Step 14.6 — the rear pair are reached at an angle from the door)
• 150 mm machinist square (the hot re-square check at Step 14.6 — the same one as Ch 06b)
• Laptop or tablet on the Mainsail console, with M112 typed and unsent in a second window for the shaper run at Step 14.13 (Ch 13 Tools)
• Part H only: string, scissors, 3 mm hex key, the soldering iron with the LDO insert tip, and the multimeter

Printed parts

STL	Qty	Colour
Exhaust housing, Part H only, printed at Step 14.26	1	Black
Exhaust fan grill, access cover and two filter mounts, Part H only, printed at Step 14.26	1, 1, 2	Blue

Hardware (chapter totals)

Fastener / part	Qty	Note
M3×8 SHCS	4: 2 nameplate + 2 exhaust	the nameplate, Step 14.24; Part H's access cover, Step 14.28
M3 roll-in T-nut	2	the nameplate, Step 14.24
M3 heat-set insert, brass M3×5×4	8	Part H only: the exhaust housing, Step 14.27
M3×30 SHCS	4	Part H only: the exhaust fan and its grill, Step 14.28
— turned, not added —	0	Outside Part H, nothing else is added or removed in this chapter. The only things you turn are the two A/B front tensioner screws, the four Z idler tensioner bolts at the top of each upright (never the Z belt clamps at the gantry corners, on the front idlers, A/B drives and Z joints), and the four Z joint M5×40 bolts, which get their first and only full tighten hot at Step 14.6.

Consumables: Prusament ASA Galaxy Black (~150 g across all test prints), IPA for the flex plate. Part H: VHB tape and zip ties from the kit, ~50 g PLA, and ~100 g ASA on the Core One+.

Read first

• Order is not intuitive and is enforced. PID before QGL (a thermally unstable machine will not QGL repeatably); e-steps before the first print; input shaper and pressure advance only after a successful first print (survey §3.3). Pressure advance changes when input shaping is enabled, so shaper comes first of the two. src
• SAVE_CONFIG restarts Klipper. Every SAVE_CONFIG in this chapter loses your homing. Re-G32 after each one. Saved values land in the auto-generated block at the bottom of printer.cfg and override anything you typed above.
• Change one thing at a time and write it down. The tuning log at the end of this chapter is the deliverable. If two things change between prints you cannot attribute the result.
• Do not chase dimensional error with rotation_distance, XY compensation or the extrusion multiplier. Ellis: deviations are material shrinkage and bulging, not axis errors; his multiplier method is aesthetics-first, judged on a top surface, and Voron parts, drawn with ABS shrinkage in mind, need no compensation beyond a good multiplier tune. src
• Shaper auto-calibration is destructive if abused. Klipper: "It is not advisable to run the shaper auto-calibration very frequently… There is also an increased risk of some parts unscrewing or becoming loose. Always check that all parts of the printer are securely fixed in place after each auto-tuning." src

Sources for this chapter:

• Voron docs — Secondary printer tuning — belt frequencies and the mesh-variance check; materials for the chamber band; initial-startup wizard for PID, QGL and e-steps
• Klipper — Measuring Resonances, Resonance Compensation, Pressure Advance, Rotation Distance, Bed Mesh, plus Config Reference and G-Codes
• leviathan-printer-rev-d-sbv2.cfg at commit 667521d — the line ranges each tuning step reads or edits
• Voron 2.4r2 Assembly Manual p.125 — the belt step that gives no frequency, which is why step 14.4 exists
• Ellis' Print Tuning Guide and the Pressure/Linear Advance tool — linked only. The guide publishes no licence, so nothing from it is copied, quoted at length or mirrored here; every reference is a link out
• Part H: Voron-2 STLs/Exhaust_Filter/ and manual p.250–256 for the housing; Voron docs — Chamber Temperature & Exhaust Fan for the pattern; Klipper temperature_fan and temperature_combined; the design record review/2026-10-03-exhaust/DESIGN.md
• E3D Revo 60 W heatercore / 104NT thermistor — the 270 °C max_temp question in step 14.2
• Step images mirrored into assets/remote/14-calibration/ from Voron-Documentation and Klipper, both GPL-3.0 — see that folder's SOURCES.txt

Video coverage (Steve Builds, pre-release LDO kit — differs from Rev D+): Extras! @1:15:59 (+10m), More Extras! @4:09:07 (+8m)

Helper steps: 14 · 14.1, 14.4, 14.5, 14.10, 14.11, 14.12, 14.14, 14.18, 14.24, 14.25, 14.26, 14.29, 14.33, 14.35

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