Saw that post in Discord from Sherry re “About First-Layer Issues
What Affects First-Layer Quality”
Do suggest to post these things here in the forum as well. Or do I overlook same ?
Suggest to add information concerning z-offset settings- there are always discussions whether or how the z-offset should be handled. Some people say they know from older printers/other systems, that managing/amending the z-offset should be made possible directly in printers menu (not only Klipper menu). They want to tinker with the z-offset.
I keep telling them my experience that when the head bed is levelled, toolhead-offset calibration is done and heatbed levelling is performed, the z-offset should be ok and does not required tinkering.
Would appreciate input from SM or others i.e. clarification, as there is quite a bit of myth around.
You are right - there is no need to tinker with z-offset these days. Unless for some niche reasons.
But you can adjust it in profiles for the print beds in slicer…
About First-Layer Issues
What Affects First-Layer Quality
V1.5.2 fixes the first-layer issue introduced in V1.5.0 that could still occur in certain scenarios in V1.5.1.
However, first-layer quality is affected by more than just the firmware. It also depends on factors such as the printer’s condition, printing environment, and print settings, including bed mesh data, multi-toolhead offset calibration, build plate flatness, filament condition, and first-layer print settings.
As a result, first-layer quality may still vary from one printer to another, even when running the same firmware version.
Troubleshooting
If your first layer is still not as expected after upgrading to V1.5.2, refer to U1 model warps, detaches or collapses and follow the troubleshooting steps provided:
Contact Support
If the issue persists after completing the troubleshooting steps above and appears to be firmware-related, please contact our technical support.
To help us investigate the issue more efficiently, please provide:
A photo of the first layer
Firmware version
Print file
Whether Heated Bed Leveling was enabled before printing
Submit a support request here:
and another one from thus mrng regarding release of 1.5.2
Snapmaker U1 Firmware V1.5.2 Released
Hi everyone,
Firmware V1.5.2 is now officially released.
This update addresses the first-layer issue that could occur in certain scenarios after upgrading to V1.5.0 or V1.5.1, and includes additional bug fixes related to nozzle detection and heating control.
After updating, please follow the instructions in the **Next Steps **section below based on your previous firmware version. If you still encounter first-layer issues or other unexpected behavior after upgrading, please contact our technical support team and provide relevant details (such as photos, firmware version, print file, and printing conditions) to help us investigate and resolve the issue more efficiently.
Bug Fixes
Fixed an issue introduced in V1.5.0 that could cause the first layer to be overly squished when Heated Bed Leveling was not enabled before printing. This issue occurred in the following scenarios:
After upgrading to V1.5.0, if Heated Bed Leveling was not enabled before printing, the first layer would be overly squished.
On V1.5.1, if the printer had been idle for an extended period and Heated Bed Leveling was not enabled before printing, the first layer could occasionally be overly squished.
Fixed false nozzle diameter mismatch warnings that could prevent prints from starting.
Fixed an issue where nozzle heating remained on after filament loading or unloading.
Next Steps
After upgrading, follow the instructions below based on the firmware version you were previously using.
If you had upgraded to V1.5.0 or V1.5.1
With all toolheads unloaded, run Multi-toolhead Offset Calibration again.
Before starting a print, make sure Heated Bed Leveling is enabled.
If you were using a version earlier than V1.5.0
No additional steps are required. The printer is ready to use.
For firmware/software releases, the official wiki is always the primary source. Different community channels then share announcements with key highlights from wiki afterward.
Z offset is usually suggested when hardware has been modified, such as first assembly, or replacing the nozzle/hotend. (Changing the build plate surface is also a hardware change, but offset compensation is already handled in the start G-code, so manual adjustment isn’t needed.)
When first-layer print quality issues arise in daily use, the first steps would be to check the build plate for contamination and verify that the bed mesh is still accurate. Heatbed leveling and toolhead-offset calibration are typically sufficient in most cases, so Z offset shouldn’t be the first thing to change. Only if the problem persists after those checks would special Z offset tuning be considered as a last resort.