How to Calibrate a 3D Printer

How you calibrate a 3D printer depends on what goes into it. If you load filament from a spool, start with the FDM steps. You’ll level the bed and print a single layer to check the gap under the nozzle. If you pour liquid resin into a vat, jump to the resin steps to check the build plate and test your exposure settings.

Table of contents

1. Get the printer ready
2. Level the bed and set the nozzle gap
3. Print a test layer and check the result
4. Tune the filament if you need to
5. Check the fit on a real part
6. When to recalibrate an FDM printer
7. Calibrate an LCD resin printer

1. Get your FDM printer ready

On a new machine, finish the unpacking checklist for your exact model. Remove any shipping restraints before the axes move. Seat the removable build plate flat on its base and check underneath for stray filament. A scrap trapped under one corner can throw off the surface you’re about to measure. If you’re still assembling the printer, start with our FDM quick-start guide.

Clean the print surface as recommended for its coating. In your slicer, select the installed nozzle size, printer model, plate type if available, and the filament you actually loaded. Start with a known material profile. If the printer was working yesterday and the only change is a new spool, check that profile and try the test layer before repeating the whole setup.

2. Level the bed and set the nozzle gap

Bed leveling and Z offset answer two different questions. Leveling accounts for how the surface sits under the nozzle as it moves across the bed. Z offset fine-tunes the starting distance between nozzle and plate. On FDM 3D printers, one routine may handle both, or the screen may walk you through them separately. Here’s what that looks like on two ELEGOO machines.

Centauri Carbon (original model) — run the built-in self-check

On first setup, remove the three transport screws securing the bed, fit the build plate as shown in the startup guide, and clear the chamber. Follow the touchscreen prompts to run the device self-check. Let the printer finish its input shaping and automatic bed leveling. The machine handles the initial Z offset as well. When it’s done, load your filament and move on to the test layer. If you flip the build plate, run the calibration again as directed in the Centauri Carbon manual.

Neptune 4 Plus — adjust the six positions, then run automatic leveling

1. Open the leveling screen and follow its homing prompts. At the center, slide a sheet of ordinary A4 paper between the nozzle and the plate. Use the screen controls to set the gap until you feel light drag and can still move the paper.
2. Start auxiliary leveling. At each of the six positions, use the corresponding knob under the bed to get a similar drag on the paper. Revisit the positions if adjusting one changes another.
3. Remove the paper and run automatic leveling. Let the printer complete its heating and probing sequence. It measures the surface at multiple points to build a height map, also called a bed mesh.
4. Return the paper to the center and fine-tune the Z offset until you can pull the sheet out but can’t push it back under the nozzle. Tap the save icon on the leveling screen. Paper gets you close. The printed layer shows whether the gap works with filament coming through the nozzle.

Using a different printer? Check its manual for the order of operations, the temperature it requires, and how it saves the result. Even closely related models can have different adjustment points.

3. Print a test layer and check the result

In your slicer, add a flat square and set its height to your profile’s first-layer height. Center it on the plate and check the sliced preview. It should show just one layer. Start the print and watch the lines fill the square. If you’re chasing a problem that shows up only on the left or right, print a second copy in that area using the same settings.

• You can see the plate between the lines. If gaps run across the whole square and the strands sit loosely on the surface, the nozzle may be starting too high. On a printer with manual Z adjustment, bring it a small step closer using the model’s controls and reprint the same square.
• The surface feels ridged after it cools. If the nozzle plows through fresh plastic and pushes it up between lines, the gap may be too small. Increase the clearance a small step and retest. Stop the print if the nozzle scrapes the plate.
• The lines join evenly and the edges stay flat. Let the plate cool and lift the square. If it comes off in one piece and neighboring strands hold together, try a small part. You can leave the offset here.

If only one corner peels up while the rest looks good, check that area for residue, reseat the plate, and verify the leveling routine for your model. Moving the nozzle closer everywhere can spoil the side that already prints well. If the whole patch lifts, check the surface and the filament’s bed temperature before changing the gap. For more examples, see our first-layer troubleshooting guide.

4. Tune the filament if a defect remains

If the first layer holds and the rest of the part looks good, save the profile and go print. If a defect persists higher up, duplicate the filament profile, change one setting at a time, and keep the original for comparison.

• Fine strings between separate features. Check the filament’s storage and drying guidance first. Try a temperature tower within the filament maker’s range. If strings remain at a temperature that gives good layer bonding, try a retraction test.
• Small gaps or excess material across solid top surfaces. Use a flow ratio test at your chosen temperature. Compare the center of each test patch and pick the one with the smoothest joined lines. Save that ratio with the filament profile.
• Bulges at sharp corners while straight walls look even. If your printer supports pressure advance, use its compatible test to tune how extrusion responds as the nozzle changes speed.

If the extruder clicks or very little plastic comes out even at ordinary speeds, check that the spool feeds freely and the nozzle is clear. If you’ve replaced the extruder and it now feeds the wrong length of filament, follow your model’s procedure for measuring how much it feeds compared with the length requested. That checks the drive itself. A flow ratio test answers a different question: how much of this filament makes a smooth, solid surface? If you use OrcaSlicer, its calibration guide walks through the test prints and shows where to save the results.

5. Check the fit on a part you actually use

Choose a feature that matters for your next project. For a lid, print a short section of the rim and see whether it fits the box. For a peg, measure the cooled peg and try it in its matching hole. Print another copy with the same settings if the fit is critical. If the results differ, solve that inconsistency before adding a dimensional correction.

A calibration cube can reveal a size difference, but one measurement mixes the effects of extrusion, cooling, and motion. Leave the factory axis settings in place while you check the model dimensions, slicer scale, and repeatability. Klipper’s rotation distance documentation explains how its axis settings are determined. Once the test part fits and a repeat print behaves the same way, save the profile with the material and nozzle size so you can find it again.

How often should you recalibrate an FDM printer?

After moving the printer or changing the nozzle or build plate, check the plate seating and repeat the model’s relevant leveling or offset routine. A one-layer square is a cheap way to confirm the result before a long print.

After switching filament, start with the new material’s profile and print a small sample. If the first layer is still even, focus on the material settings that affect the rest of the print.

Before a routine print, follow any automatic checks your model calls for and watch the first few lines. When they join cleanly and the part stays put, let it run.

How to calibrate an LCD resin printer

On an LCD resin 3D printer, start with two checks. Does the print hold across the build plate? Once it does, can the resin reproduce the fine details in a small test model?

1. Set up the build plate for your model. Follow its startup routine. The Saturn 4 Ultra handles leveling automatically. The Saturn 3 Ultra uses a manual procedure, shown in ELEGOO’s build plate leveling video. If parts consistently peel away on the same side, check plate leveling before you change the resin settings. Choose your exact model in the ELEGOO leveling guide.
2. Print a small exposure test. Start with the recommended profile for your printer, resin, and layer height. Use an exposure test model with a reference showing how its details should look. A screen exposure check only shows whether the LCD displays its test pattern. You need a printed sample to judge how the resin cures.
3. Compare the same features each time. Look at the openings and raised details on the test model. If small openings close up, try a slightly shorter normal-layer exposure. If fine raised details are missing, try a slightly longer one. Keep the layer height and other settings the same, then print the same test again. When the openings stay clear and the fine features hold, save that profile with the resin name and layer height.