In some cases, the build plate (Z stage) on UltiMaker 3D printers may drop unexpectedly, especially during the print preparation stage. This article explains the likely causes of this behavior and how to resolve or prevent it.
Note: This issue could potentially happen on several UltiMaker 3D printers, but is more often observed on the Factor 4, S6 (Flex variant), S7, and S8 due to the weight of the Z stage.
When does this happen?
This issue most often occurs just before a print starts, at the beginning of the active leveling process. In that case, the following symptoms may be observed: the build plate begins to rise but does not reach the top of the build volume, a screeching sound may be heard, and the Z stage suddenly drops back down. When this happens, the printer will typically trigger an active leveling error and stop the print.
You may also observe the same behavior when you manually select the option Raise build plate via the Maintenance menu.
Although less common, the issue may also occur during a print. In such cases, the print may fail without a clear error message. If you notice the build plate has dropped mid-print, abort the print via the display or Digital Factory. Because this failure mode is mechanical in nature, the printer may not always detect it automatically.
What causes this?
The Z stage is moved by a stepper motor with a long lead screw. On some UltiMaker models, such as the Factor 4 and S series printers with a flexible build plate, the Z stage is relatively heavy. If the lead screw is dirty or not properly lubricated, the resistance during upward movement increases. This can exceed the torque capacity of the Z motor, causing it to lose power momentarily. When this happens, the build plate may drop abruptly.
How to prevent it
Regular maintenance of the Z lead screw is essential to ensure smooth and reliable build plate movement. Proper lubrication reduces friction and helps the motor lift the build plate consistently.
You can recognize a dirty lead screw by its appearance. If it looks completely black, this is a sign that dust and debris have built up in the threads. A dry or dirty lead screw will also feel more difficult to move manually.
For all S series printers and the Factor 4, it is recommended to clean and lubricate the Z motor lead screw every three months or after 300–500 printing hours. Use a clean cloth or paper towel to remove as much dirt and old grease as possible. Then apply fresh grease and raise and lower the build plate to distribute it evenly across the screw. This can be done manually or using the Build plate option in the menu.
Tip: The recommended grease (Eurol) is included in the accessory box for S series printers, in the Maintenance Kit for the Factor 4, or can be ordered separately from your local reseller.
For detailed instructions on lead screw maintenance, see:
Need further support?
If the issue persists after maintenance, or if you hear unusual noises or resistance during Z-stage movement, contact UltiMaker Support for further assistance. Please include all relevant information, such as your printer model, serial number, log files, and preferably a video of the issue.
