During the active leveling process, the printer will move the bed up to the nozzle to detect the height of each print core and any possible variations in the build plate. During printing, the firmware will then correct for these offsets during printing. The Ultimaker 3, Ultimaker S3, and Ultimaker S5 use active leveling.
Note: The active leveling process is influenced by the state of multiple aspects of the printer and print head. This article contains checks on all these parts. Please follow them carefully to improve the reliability of the active leveling process and to get the most accurate results in the leveling sensor diagnostic.
In case of active leveling problems, it is always important to observe the printer's behavior and determine during which step the leveling process fails:
|Behavior||Error message||Suggested actions|
|Printer probes the Z offset for the two print cores in the back-right corner||Difference exceeds realistic values||
|Printer probes the Z offset, but the build plate does not touch the nozzle in slot 1||Nozzle offset probe failed||
|Printer probes the full build plate||Active leveling could not be performed||
The above are the most common scenarios and solutions for active leveling failures. For more detailed troubleshooting advice, please see the sections below.
Active leveling detailed checks
There are many potential causes for leveling issues and many possible actions to correct the behavior. Please perform and verify all steps below to get a reliable result:
1. Clean the nozzles
Material that is stuck to one or both of the nozzles can influence the readings. Although the nozzles are heated up before the procedure begins, if a blob of material is too big, it will not melt away completely and will add to the height of the print core.
Before restarting active leveling, clean the outside of the nozzles.
2. Replace the print cores
If the active leveling problems appear consistently with a particular print core combination, the problem could be caused by one of the print cores. The expected offset between the two nozzle tips is 1.5 mm. If the nozzle of one of the print cores is worn down (for example, if the tip is flattened due to the use of abrasive materials), the measured offset will be either too big or too small.
Inspect the print cores closely. If any damage or wear and tear is observed, replace the print core.
1. Clean the build plate
When a nozzle is pressed against the glass during active leveling, this can leave behind some filament residue on the plate. This residue can cause inaccuracies in the readings if you go through the active leveling procedure again. Make sure there are no impurities on the surface of the glass plate, especially in the back-right corner where the Z offset probe is done.
Note: A thin layer of glue correctly applied to the glass plate will not affect the readings during active leveling.
2. Manually level the build plate
For active leveling to work correctly, there should be some space (at least 0.5 mm) between the tip of the nozzle and the glass plate at the start of the procedure. If the nozzle is already touching the glass, the printer cannot perform the measurements correctly.
After having followed the manual leveling procedure multiple times, the build plate springs can become too loose and the bed too high. Turn the three thumb wheels below the build plate counter-clockwise to tighten the screws. Reset the bed back to the factory position:
- For the Ultimaker 3 and S3, there should be a distance of approximately 14 mm between the bottom of the heated bed and the top of the aluminum base plate.
- For the Ultimaker S5, the thumb wheels should be fully tightened. Then, loosen with 2 full turns clockwise.
1. Check the lift switch calibration
It is important that the print core switching functions well. If not, the active leveling procedure will detect the same height for both cores, which also 'exceeds realistic values' and could therefore cause this error message.
If the print head does not move to the switch bay correctly, perform a lift switch calibration to properly store the position. This only takes a few minutes. Our support pages have detailed instructions on how to perform this calibration for S-line printers and for the Ultimaker 3.
2. Check the capacitive sensor wires and connector
The capacitive sensor board which enables active leveling is located in the front fan bracket of the print head. This is connected with a red (sensor) and white (shield) wire. Check if both of these wires are still properly connected. If they have come loose or show signs of damage, the capacitive sensor wires must be reconnected or replaced. Contact support for further assistance.
See the following pictures for reference:
OK: Both wires are securely connected to the board and no damage is visible
|Not OK: One of the wires is broken and disconnected from the board|
Also check the connection of the wires to the print head PCB. This connector is visible at the back of the print head. The capacitive sensor wires are the second connector from the left, as seen from the back:
3. Check the front fan cable
If one of the wires of the front fan has become damaged through wear and tear or improper placement, it could lead to electrostatic interference on the capacitive sensor board. This would result in incorrect readings during the active leveling process.
It is not easy to check the whole wires without disassembling part of the print head. Instead, try temporarily disconnecting the front fan before retrying active leveling. The front fan (black-white wires) is the third connector from the left, as seen from the back:
Tip: If it is not possible to easily disconnect the fan, you can remove the two screws on each side of the header bracket, to slightly lower the side fan bracket. After disconnecting the fan, realign the side fan bracket and secure it with the screws.
Start another print and observe the leveling process. If active leveling succeeds with the front fan disconnected, the fan is defective. When the wire's insulation is damaged, the core can come into contact with the metal fan bracket, which disrupts the leveling measurements. The front fan should be replaced; contact your local reseller or submit a support ticket for further assistance.
Warning: Only disconnect the fan for testing purposes; do not run prints with the front fan unplugged. Stop the print after the active leveling process is done. The front fan cools the print cores. Without it, the filament will swell in the print cores, causing extrusion failures. In severe cases, the swell may block print core removal. If this happens, you will need to disassemble the print head.
4. Check the fan bracket alignment
Make sure that the fan bracket closes properly and the bottom of the print head is completely flat. If the fan bracket, which contains the capacitive sensor board, is at an angle to the build plate, the readings will not be accurate.
If it is tilting forward, something may be preventing the bracket from closing completely. This could be due to material on the print core's heater block, an incorrectly placed nozzle cover, or an incorrectly placed fan. When it's tilting backward, the metal of the fan bracket could be bent. In these cases, it is recommended to contact support for further assistance.
1. Stable position
Active leveling relies on precise measurements. Ensure the printer is on a stable and flat surface. Touching the printer or print head during the leveling process can interfere with the measurements and corrupt the results.
2. Electrical interferences
Ensure the printer is not affected by electrical interferences. These interferences could be caused by WiFi, radio, light sources like neon, other machinery, and more. When in doubt, try moving the printer to another location and retry.
The Ultimaker S5 has a diagnostic feature to check the active leveling hardware. In the main menu, click on the gear icon, then select Maintenance. Scroll down to find Diagnostics, and start the Leveling sensor test. This diagnostic test will check the signal and the noise of the capacitive sensor.
Note: This test behaves differently than the active leveling procedure at the start of a print. The build plate will move upward, close to the nozzles, but does not press against them. This is normal. Do not touch the printer during the test.
After the test is finished, the display will show the result. The leveling sensor noise level is displayed as a number. Contact Ultimaker support by submitting a ticket as described below and share the outcome of this diagnostic for further assistance.
Note: This test changed in firmware version 7.0.3. Previous firmware would show either that the sensor is ok, or display error code ER45. Future firmware versions will include more detailed information on acceptable noise levels.
Need further support?
If the problem still persists after trying all the troubleshooting steps listed above, please contact support by submitting a ticket. For the most efficient help, please share the following information:
- Which error message(s) you see
- The printer's log files
- The outcome of the print head diagnostic test
- A video of the active leveling behavior
- Photos of the print head and capacitive sensor
- The outcome of the attempted troubleshooting steps