Ender 3 Maintenance
Leveling, Tramming, and Z-Offset
I know you want to just change the Z-Offset, Dont! The Z offset really shouldn't change unless the distance from the nozzle to the bed level probe changes. Please please try tramming and re-meshing before changing the Z offset.
Okay, with that out of the way, lets discuss the multiple leveling mechanisms of the Ender printers.
First off is bed tramming. This is what we are used to with the Ultimakers and other printers. Bed tramming is the process of using the knobs on the bottom of the bed to ensure the bed is flat with respect to the print gantries.
To tram the bed Select "Bed Tramming Wizard" from the printer quick settings (located under the 4 big buttons on the main screen) and let the printer do its thing. It will use the ABL (Auto Bed Level) probe to see how out of tram the print bed is, and direct you on how to turn the knobs to fix it. The knobs follow the Right Hand Rule so turning the knobs counter-clockwise will result in the bed moving up under that knob.
Repeat the tramming wizard until the points are all within .03mm, then proceed with creating a new bed mesh.
ABL Mesh
The Enders utilize the ABL sensor to compensate for fluctuations in bed height. This is accomplished using the ABL mesh. The printer takes a series of 36 points around the bed and moves the z-head up and down based on those measurements.
Once you have trammed the bed, you should create a new mesh. This will remeasure those 36 points and save them to the printers memory. Do this under Advanced-> Mesh Leveling-> Auto Build Mesh. After the points are collected, you will see a representation of the mesh, make sure to hit save to commit these to memory.
But Bennett? this is only a snapshot of the bed! Wont these points change with use? Yeah, they will. The biggest thing that will happen with use is the bed will slowly come out of tram. Such is the circle of tramming. But we do have a solution to at least mitigate this issue!
Before every print, the printer will take measurements of the 4 corners of the print bed. It will use these measurements to "tilt" the mesh we made before. This means that the mesh we made should stay pretty accurate for a long time.
Take a look at skirts!
Skirts have a use more than just being a better purge line. Skirts let us see how level the bed is at a glance. When you take prints off of an ender, take a look at the skirt outline. If it's too dark, or dark in one spot you should tram and remesh the bed.
Okay, I trammed and remeshed, but adhesion is still bad!
This is where z-offset comes in. Z-offset directly affects the height of the print nozzle relative to the bed. Lowering the Z-Offset will make the head dig in more to the print head, Raising the Z-Offset will make the head go up. We want adhesion, but just barely. Make sure lines drawn next to each other touch. looking at a skirt can be a quick way to set the offset effectively.
On the enders, offset can be adjusted during a print under "tune" and outside of a print under Advanced-> Mesh Leveling.
Changing Filament
The enders have a more manual filament changing process than the Ultimakers. To take out filament, go to filament management and select the option to remove filament. This will heat up the extruder, and pull the filament out of the head.
After this, press the filament release lever on the left side of the printer (where the extruder motor is) and pull out the remaining filament.
To insert filament, just heat up the extruder and push freshly cut filament through until it comes out the extruder.