How to calibrate a custom-built Voron for printer builders

Q: What can LunarWerx 3D Print help with?

They run in a web browser and you use them on a website hosted on Cloudflare. One checkbox slows the first layer to 15 mm/s by default, and the maker says it then sticks to a clean plate without glue.

A practical guide for printer builders to calibrate a custom Voron step by step, with tools that can help and mistakes to avoid.

By TexHouse · 2026-10-12

TexHouse is published by the makers of LunarWerx 3D Print, Vector3D and MeshyDL, which are compared here alongside other tools.

Calibrating a custom-built Voron involves checking the printer setup, adjusting key print settings, and verifying results with test prints. This guide covers common steps and shows tools that can help with specific parts of the process.

Option	What it does	Fee
LunarWerx 3D Print	Browser tools that work out ironing settings, check parts for injection moulding and design 3D-printable foam inserts ^[1]	Not included in source comparison
Klipper firmware	Firmware that drives the printer and provides calibration commands for probe, mesh, and pressure advance	Not published
OrcaSlicer	Slicer with built-in terminal and calibration print generation for flow and retraction	Not published
SuperSlicer	Slicer with calibration print generation and detailed printer profile settings	Not published

What you need before you start

Before calibrating a custom-built Voron, have a few things ready. A complete, squared frame is the foundation; check that every extrusion is tight and the gantry moves without binding. A working probe is needed for bed leveling and mesh compensation, and a set of calipers helps measure filament diameter and printed test parts. Keep the firmware configuration file open, because most calibration changes happen there. Have a roll of the filament actually used for prints, because flow rate depends on the real diameter and material behavior. A clean PEI or other build surface is also needed, because residue and oil from handling change how the first layer sticks. Finally, have a way to send G-code commands and watch the printer respond, whether that is a terminal in a slicer, a web interface, or a USB serial console. A notebook or text file to record results after each step is useful, because calibration is a sequence of small changes and the numbers add up.

Step by step

Square the frame. Loosen every frame joint, set the printer on a flat surface, and tighten each bolt in order. A frame that is not square makes later calibration harder.

Set the Z endstop. Move the nozzle to the bed and adjust the endstop switch or sensorless homing trigger point so the nozzle just touches the build plate at the homed position. In the firmware, set the Z offset so the reported position matches where the nozzle actually is.

Calibrate the probe. Run the probe calibration sequence so the probe triggers at a known offset from the nozzle. This offset tells the firmware how far the probe is from the tip, and it must be measured at the same bed temperature used for printing.

Build a bed mesh. Run the bed leveling command to probe several points across the bed and record the height at each. Save the mesh so it loads on every print. A good mesh compensates for small dips or bumps in the build plate.

Tune the Z offset for the first layer. Print a single-layer square and adjust the Z offset until the lines press into each other without gaps and without scraping.

Measure flow rate. Print a hollow cube with one wall, measure the wall thickness with calipers, and adjust the flow ratio until the measured wall matches the target. Voron documentation gives the formula for this.

Set retraction. Print a retraction tower and find the shortest retraction distance that gives clean travel moves without stringing. Too much retraction can cause under-extrusion on direct drive systems common on Voron builds.

Check pressure advance. Run the calibration pattern and find the value that gives consistent line width at the start and end of each move. This reduces bulging corners and thin ends.

Verify with a real print. Print a known calibration model and look for layer adhesion, surface finish, and dimensional accuracy. Make small adjustments and reprint if needed.

Tools that can do it

Several tools can help with parts of the calibration process. The tools here are options, and each does what its source says it does.

LunarWerx 3D Print is made by the team that publishes this site. It provides browser tools that can help with ironing settings and other 3D printing tasks. ^[1] It runs in a web browser ^[1] and you use it on its website, which is hosted on Cloudflare. ^[1]

For ironing, it works out ironing settings for your printer, material and finish and exports a ready 3MF file. ^[1] It makes a 9-pad or 16-pad test plate around your settings, and you mark each pad as worked or not. ^[1] You can click flat top surfaces, and the export adds a modifier part over each picked surface. ^[1]

For Bambu or Orca users, for an uploaded Bambu or Orca project it adds per-object ironing settings and keeps the rest of the file unchanged. ^[1]

It also checks a part for injection moulding with 13 checks, shows shrinkage, pressure and weak-point maps, and builds the two mould halves; all numbers are estimates. ^[1] It lays parts out in a box and designs a 3D-printable foam tray and top pad that each part lifts straight out of. ^[1] The foam insert is split into pieces that each fit your printer's bed. ^[1]

When you open an STL file with faces turned backwards, it turns them right side out and says how many it fixed. ^[1] It runs in your browser, and sign-in with Connections lets your settings, recent test plates and print results be available through that account. ^[1]

The code package is marked private, not public. ^[1]

Klipper firmware is what drives the printer and is where probe calibration, bed mesh, and pressure advance commands live. The Klipper documentation gives the exact commands and formulas for each calibration step.

OrcaSlicer is a slicer that can prepare G-code and send it to the printer. It includes a built-in terminal for sending commands and a calibration menu for flow and retraction towers.

SuperSlicer is another slicer option that offers calibration print generation and detailed printer profile settings. It exports G-code tuned to the settings in your calibration process.

Common mistakes to avoid

Skipping the frame squaring step is a mistake. A frame that is slightly off makes the gantry tilt, and no bed mesh can fully fix that. Always square first.

Calibrating the probe at the wrong bed temperature causes errors. The bed expands as it heats, and a probe offset measured cold will be wrong when the bed is hot for printing. Measure at the temperature used for real prints.

Setting the Z offset once and never checking it again is a mistake. Different filaments and different bed surfaces need different offsets. Recheck after changing either.

Over-tightening belts is another common error. Belts that are too tight put load on the motors and can cause skipped steps. Belts that are too loose cause ringing and ghosting. Follow the Voron belt tension guide and use a phone app or gauge to match the target frequency.

Ignoring input shaping is a mistake on a coreXY printer like a Voron. Input shaping compensates for vibrations at print speeds and produces cleaner walls. Run the calibration and apply the result.

Frequently asked questions

How do you set the Z offset on a Voron?

Move the nozzle to the bed at print temperature and adjust the Z offset in the firmware until the nozzle just touches the plate. Print a single-layer square and fine-tune the offset so the lines press together without gaps or scraping. The offset changes with different bed surfaces and filaments, so recheck after a change.

What is pressure advance on a Voron?

Pressure advance is a Klipper setting that balances the flow of filament at the start and end of each move so lines start and end at a consistent width. You calibrate it by printing a pattern and finding the value that gives even line width. It reduces bulging corners and thin line ends.

How do you calibrate flow rate on a Voron?

Print a hollow cube with a single wall, measure the wall thickness with calipers, and compare it to the target. Use the flow ratio formula from the Voron documentation to adjust the flow rate until the measured wall matches the target. Check the real filament diameter first, because flow rate depends on it.

What can LunarWerx 3D Print help with?

They run in a web browser ^[1] and you use them on a website hosted on Cloudflare. ^[1] One checkbox slows the first layer to 15 mm/s by default, and the maker says it then sticks to a clean plate without glue. ^[1]

How often should you recalibrate a Voron?

Recalibrate the Z offset whenever you change filament, bed surface, or nozzle. Recheck the bed mesh if you move the printer or change the build plate. Flow rate and retraction may shift with a new roll of filament. Pressure advance stays stable unless you change speed or acceleration settings.

The tools are free to use. ^[1]

Try LunarWerx 3D Print

Sources

LunarWerx 3D Print's own description of itself (the product of this site's publisher)