Calibrating the Z-Axis Offset
How Calibration Works
*Note: Please do not worry if you do not see the homing pin mentioned in the article. Later versions of the Z18 may not have the mentioned homing pin and instead just have a black bar that goes across the back of the plate. This will serve the same function as the pin.
At the beginning of each print, the Smart Extruder+ or Smart Extruder on your MakerBot Replicator Z18 will tap the homing pin, a small metal pin in the back right corner of the build platform or a black bar that covers the back center portion of the build plate. This lets your MakerBot Replicator Z18 know how high to position the build plate at the start of a print.
There is a slight difference in height between the homing pin and the build plate. If this difference isn't recorded correctly, your MakerBot 3D printer won't position your extruder at the correct height. To make sure the recorded position is correct, you can run the homing calibration script.
The Homing Calibration Script
Select Settings > Calibration > Calibrate Z Offset. You can also run this homing calibration script through MakerBot Print. Navigate to Utilities > Calibration, and click Z Calibration. Then click the Run Home Calibration button and follow the prompts.
During the homing calibration routine, the extruder nozzle will tap the homing pin (or the black bar) and the build plate and calculate the distance between the two.
When the process is finished, run a test print using one of the example files in MakerBot Desktop. To find these files, go to File > Examples. If the test print is still starting at the wrong distance from the build plate, repeat the calibration process.
If running the calibration script a few times doesn’t resolve the issue, run the script one more time. This time, check to make sure the extruder nozzle is touching the homing pin (or the black bar) during the calibration process. The homing pin is a silver-colored metal pin located at the back right corner of the Z stage.
View of the build plate from above
If the extruder nozzle is not making contact with the pin or the bar during the calibration process, there may be a mechanical problem with your MakerBot Replicator Z18. If this is the case, please submit a case to MakerBot Support.
Manually Adjusting the Z-Axis Offset
If the extruder nozzle is making contact with the homing pin during the calibration process but your Smart Extruder+/Smart Extruder still doesn’t seem to be starting prints at the correct distance from the build plate, you can change the starting height by manually adjusting the Z-axis offset. Be careful: bringing the nozzle and build plate too close together can damage your build plate.
In MakerBot Print, navigate to Utilities > Calibration. Then click on Z-Axis Offset. There you will see a picture of your extruder in relation to the build plate. Next to that is a slider, which should be set to “Default” at 0.00 mm. To avoid damaging your build plate, move the slider no more than one notch at a time; each notch is the equivalent of approximately .1 mm. To increase the space between the nozzle and the build plate at the start of a print, move the slider down. To decrease the space, move the slider up. Then click Apply Changes. After running the homing process at the start of a print, your MakerBot Replicator Z18 will incorporate the distance you set and will raise or lower the build plate by that additional amount.
Continue making incremental changes until your MakerBot Z18 is starting prints at the correct distance from the build plate.
You can also perform this adjustment through the MakerBot Mobile. Click here for information on accessing the Mobile app's Z-axis offset utility.