ZOFFSET

If you're struggling to get your 3D prints to stick or want to print on top of an existing model, Z offset is the answer. Learn more!

What Is It?

The offset can be positive or negative depending upon if the bed is too close or too far away.
The offset can be positive or negative depending on the bed's position (Source: bladefire doomsday via YouTube)

For many 3D printing enthusiasts, getting the perfect initial layer dictates the quality of the resulting print. A key to this is setting the right Z offset, which is the distance between the hot end and the Z home position on 3D printers.

Ideally, this would match the distance between the hot end and the print bed. However, differences in limit switch position, homing probes, and manual bed leveling complicate this issue.

Why Adjust It

The most common reason for adjusting the Z offset is to allow for the addition of a glass or thicker bed material. Other reasons include the following:

  • Printing directly on top of an existing object (for example, printing directly on glass to make a picture frame)
  • Embedding magnets inside a print (for example, by pausing mid-print)
  • Fine-tuning the first layer for perfect printing

There are two methods of adjusting the Z offset: altering the G-code or directly inputting the offset in a slicer. In this article, we’ll explain both. Let’s get to it!

Adjusting with G-code

G-code can be used to adjust the Z offset.
G-code can be used to adjust many different settings (Source: Robotics and Automation News)

The key to adjusting Z offset using G-code is to home the printer first with G28 Z0.

Next, G92 Z0.1 can be used to set a manual Z offset for printing. In this case, the printer has established the current (home) position to be Z = 0.1 mm. This will create a -0.1-mm offset, where any movement command after this will be lowered by 0.1 mm on the Z-axis.

Note: To raise the nozzle to print on a surface, you’ll want to use negative values of Z offset (Z-0.1). This will shift the head up (0.1 mm).

 

Adjusting with a Slicer

Z offset can be set under the
Z offset can be set under the "Build Plate Adhesion" menu item in Cura (Source: Benjamin Goldschmidt via All3DP)

Adjusting the Z offset using the slicer can be much easier than doing it manually in G-code. The exact location of this feature will depend on the slicer you’re using, but here we’ll walk you through the steps for the commonly used Cura. You’ll need to install a plug-in to access the Z offset settings. Here’s how:

  1. In the latest version of Cura, 4.9.0, go to the marketplace by clicking on the icon in the upper right-hand corner of the screen. This will bring up a box of downloadable plug-ins.
  2. Navigate to the bottom of the list and click on the icon called Z Offset plug-in.

Once installed, you can access the setting under the “Build Plate Adhesion” dropdown box to set the amount of offset.

Final Thoughts

Image of: Final Thoughts
Accidental collision with the printhead is what you want to avoid! (Source: SirHodges via Reddit)

Yes, it’s that easy! However, there are still a couple of things to keep in mind.

First, problems can occur when inputting a Z offset that causes the printhead to hit the limit switch. This will prevent the offset from occurring as it overrides any written G-code.

Secondly, if you’re trying to print on a significantly uneven object, you might have issues. If the printhead runs into the object as it travels to start the first layer, you accommodate this by adding G-code. However, it’ll have to be specific to the object being printed on.

Overall, adjusting the Z offset is an easy process that will expand what you can print. Using this guide, you’ll reach new heights in no time!

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