When beginning your 3d printing journey it probably feels like a million things could go wrong. Is my bed level, is it too cold, is my filament wet? And the list goes on…
Maybe, you need to calibrate your Z offset. Maybe, you aren’t even sure what the heck I’m talking about. Either way, stick around to learn what, how, why, and when you might need to calibrate your Z offset.
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What is Z Offset?
Z offset is the distance between the hot end and the Z-home position on your 3d printer. In other words, it is the distance between the nozzle and the build plate when you start printing. If your Z offset is off, it can dramatically affect how your first layer turns out, and as you’ve probably heard, the first layer is the most important when determining print quality.
Do I Need to Calibrate the Z Offset?
The most common reason why people need to calibrate their Z offset is if they added an upgrade such as a glass build plate or auto bed leveling system. Another reason why you might need to change your Z offset is if you want to print on top of an existing model.
For the most part, if you have your original bed and haven’t added an auto leveling system, you shouldn’t need to calibrate Z offset. (Even then, many people add a new bed and print on top of an existing model– all without changing their Z offset).
The only time you really need to calibrate Z offset is when upgrading with an auto bed leveling system.
Z offset too high: If your prints are coming off the bed, and your filament looks like a perfect little round bead while coming out of the extruder; your Z offset is probably too high.
Z offset too low: If your print is looking very thin and spaced out, or maybe even scraping the bed a little, and the filament looks “smooshed” coming out; then your Z offset is likely too low.
Z offset just right: If your prints are sticking, don’t look too thin, and the filament is coming out looking like a compressed bead; then your Z offset is just right.
What Should the Z Offset Be?
If you are starting with a brand new machine, and no upgrades have been added, your Z offset should be set to zero.
If you have an upgrade or print where you need to calibrate the Z offset, then keep reading through to determine what your Z offset should be.
Interested in more upgrades? Check out Ender 3 Upgrades That are Actually Useful.
Calibrate Z Offset for BLTouch (Most Common)
The BLTouch is an auto-leveling sensor kit that will save you time and frustration. Much like having a Z-offset that is not the right distance, an unlevel bed will also give you adhesion problems and a poor first layer.
Luckily with the BLTouch, both of these issues are very easily solved.
Check out our YouTube on how to calibrate Z offset with Ender 3 V2:
Step 1. Turn up your bed temperature. In this demo, we set it to 65°C. Wait for about 5-7 minutes until the printer reaches temperature.
Step 2. Auto-Home Your Printer. Go into the “Prepare” menu and click on “Auto home”. Auto home basically tells your printer to go to its start or zero position.
Step 3. Move the nozzle to x117, y117. Go into the “Move” menu and click on “MoveX” and “MoveY,” change both these values to 117.
Step 4. Slowly lower the Z value. Here, you will need to use your judgment and find your Z offset “sweet spot”. In the same “Move” menu change “MoveZ” to 3. Observe the distance between the nozzle and print bed and keep lowering, as needed. Once you get close, move in smaller increments.
Step 5. As you are slowly lowering your Z offset, use a piece of paper, like a sticky note to feel in between the nozzle and print bed. If you can move the paper easily between the nozzle and the bed, keep slowly lowering your Z offset. Once the nozzle is scratching the paper and there is a little bit of resistance, your Z offset is calibrated. Note your Z offset value.
*For the textured PEI bed used in this demo, the paper being a little bit loose works well. You may want your Z offset a little bit lower, depending on your bed and print material. Use your best judgment from when you used to manually level, you may want to step down another 0.04 once or twice.
Step 6. Manually level the bed one last time to ensure that all four corners are even. Although the BLTouch can compensate for this, it will put less stress on your Z motor.
Step 7. Double-check your values.
Calibrate Z Offset Using Ender 3 Firmware
You can calibrate the Z offset using your Ender 3 firmware (AKA Marlin firmware). Changing Z offset this way allows you to do it directly on your 3d printer’s display screen. The concepts are essentially the same in the above video.
Step 1. Manually level your printer bed.
Step 2. Turn up your bed temperature. In this demo, we set it to 65°C. Wait for about 5-7 minutes until the printer reaches temperature.
Step 3. Auto-Home Your Printer. Go into the “Prepare” menu and click on “Auto home”. Auto home basically tells your printer to go to its start, or zero position.
Step 4. Move the nozzle to x117, y117. Go into the “Move” menu and click on “MoveX” and “MoveY,” change both these values to 117.
Step 5. Slowly raise or lower your Z value. Here, you will need to use your judgment and find your Z offset “sweet spot”. In the same “Move” menu change “MoveZ” up or down. Observe the distance between the nozzle and print bed and keep lowering, as needed. Be sure to move in small increments.
Step 6. As you are slowly changing your Z offset, use a piece of paper, like a sticky note to feel in between the nozzle and print bed.
If you can move the paper easily between the nozzle and the bed, keep slowly lowering your Z offset, it is too high.
If the paper does not fit or is very tight under the nozzle, keep slowly lifting your Z offset.
Once the nozzle is scratching the paper and there is a little bit of resistance, your Z offset is calibrated. Note your Z offset value.
Step 7. Manually level the bed one last time to ensure that all four corners are even.
Step 8. Double-check your values.
Step 9. Test print, and repeat steps as needed to get your perfect Z offset value.
Use a Slicer to Calibrate Z Offset
You can use your slicer to calibrate Z offset. Calibrating Z offset using a slicer is not ideal since it will take a lot of trial and error, in the process wasting filament and possibly even scratching your print bed if set too low.
If you were to do anything with Z offset in your slicer, I would change it to an already pre-determined value using the methods above.
To change Z offset in PrusaSlicer:
Step 1. Make sure you are in Advanced/Expert mode.
Step 2. Go to Printer Settings > General > Z offset.
Step 3. Enter your Z offset value.
Step 4. Print something using your Z offset value, repeat steps as needed until you have the desired Z offset.
Z offset Using G-Code
You can calibrate your Z offset by using G-code. G-code is a list of commands that your printer goes through and uses to print.
You can also use G code to send a list of commands to change your Z offset. Similarly to using your slicer to calibrate Z offset, you will need to go through a lot of trial and error to get the right Z value dialed in. Except, in this case, you also will need to be familiar with G-code.
While this method is definitely doable, it is not recommended for beginners.
For related readings, check out our Material guides and full troubleshooting guide here:
3D Printing Troubleshooting Guide: Fix Every Common Print Problem
PLA vs PETG vs ABS: Which Filament Should You Use?
Conclusion – Calibrating Z Offset Ender 3
Z offset is the distance between the nozzle and your build plate. You shouldn’t need to calibrate your 3d printer z offset unless you add an upgrade, like a glass build plate or auto-leveling system.
Calibrating Z offset Ender 3 for BLTouch is relatively straightforward using firmware. You can also calibrate Z offset using your Slicer and G-code but these methods are more difficult.