One of the most important factors that determines whether a 3D print will be successful or not is the set distance from the nozzle to the bed on the first layer. If set too close, the nozzle could jam and you could destroy your printing surface or the nozzle itself. If set too high from the bed, the print will not have good bed adhesion and will most likely lift or warp during the printing process.
If not set correctly, a first layer offset that is too high from the bed on the first layer can cause the print to lift, and possibly come off the build plate completely.
In the past, different versions of the firmware had to be installed in order to correctly set the first layer. With the new 1.65 touchscreen update, you can now change the first layer height within the touchscreen, without having to install different firmware versions. Reasons to change this setting include changing to a new nozzle, or using a new piece of glass on the bed.
The Z – OFFSET, along with other calibration settings can be found in the SETTINGS menu under ADVANCED.
The diagram was created to better show the side profile shapes of extrusions at different first layer heights. Figure 1 shows the extrusion too close to the bed. Figure 2 shows the extrusion too far. In Figure 3, the extrusion is flat, but not pressed into the bed. This is the correct extrusion profile shape to look for when making adjustments.
This diagram shows the side shape profiles of the extruded plastic at different Z Offsets. Figure 3 shows what to look for when making final adjustments.
In order to check to make sure your first layer is set correctly, print a test print using default settings in APEX. If the extrusion lines are not connecting, or if the extrusion looks round instead of flat, stop the print, then go into SETTINGS-> ADVANCED and adjust the first layer height by selecting a Z Offset letter closer to A. A is the closest to the bed, while K is the furthest. You can also access this menu by pressing the firmware version located in the top right hand side of the touchscreen.
This print is showing extrusion lines on the first layer not touching each other. This is a common sign of a Z offset being too high.
The Z OFFSET menu can be easily accessed on the HOME screen in the top, right hand corner. Simply press the firmware number and the Z OFFSET menu will pop up.
Try the print again. Repeat the previous step until you get a more flat extrusion, while making sure the nozzle isn’t dragging on the print surface. If the sample print starts off too close to the bed, go in the opposite direction towards G. This will raise the nozzle further away from the bed for the first layer.
This print shows the Z OFFSET is set too low. The print is being pressed into the bed and will most likely jam after a few more layers of printing.
After making adjustments and setting the first layer Z OFFSET correctly, the print will have a great foundation for the subsequent layers.
You can also view this lesson at airwolf3du.com.