Ender-3 Maintenance

The 3D printers at Hackberry Lab should be operated and serviced ONLY by trained lab assistants who know what they're doing, or failing that, can take accountability for their screw-ups.

This document is intended as a manual aimed at Hackberry lab assistants for guidance on maintaining the ever-growing fleet of printers. Knowledgeable lab assistants are encouraged to add their wisdom as more issues arise and new problems are solved.

Maintenance tasks that should be performed at regular intervals. When the printers are being used heavily, these should be done every night at the start of the shift.

Lab assistants should regularly ensure that the printer beds are leveled properly. Improperly-leveled beds cause print failure and damage to the beds and nozzles. Bed leveling can look different depending on whether or not a touch sensor is installed for automatic bed leveling. A printer bed is level when the nozzle is the correct height from the bed across the entire surface. At a good height, the nozzle should leave behind a solid line that isn't too flat but can't be rubbed off with your finger.

In essence, leveling a bed manually involves adjusting the height of the bed until it is an ideal distance from the nozzle at each corner and the center. The four wheels under the bed adjust the height of the bed. Put a piece of paper in between the bed and the nozzle; the bed is an ideal distance from the nozzle when the paper can be moved freely, but with slight resistance.

It can be hard to remember which way to turn the wheel to raise/lower the bed. If you think of the bed being closer to the nozzle as “tighter”, and further from the nozzle as “looser”, then the “righty-tighty lefty-loosey” rule applies from a top-down perspective.

There are several methods for doing this, but they are all just different ways of getting the nozzle down to the print bed and moving to each position in sequence. Currently, the common way of doing this in the lab is using the print server. Instructions are as follows:

1. Select the printer on the 3d print computer
2. Console > Wizards > Manual Bed Leveling
3. Follow the instructions to move the nozzle to each location
4. Adjust until level at each location
5. "Finish" to exit the wizard

Automatic bed leveling uses the BL-Touch add-on to level the bed “semi-automatically”. It works by taking measurements of the bed height in a grid and uses that data to compensate during printing. To “level the bed”, you need to have the printer perform the measurements again. To do this, use the printer menu and navigate to:

Motion > Level Bed

The printer will then retake the bed measurements. This should be done at the same frequency of manual bed leveling.

A self-leveling printer uses a value called the “Z-Offset” to translate between the bed height measurement and the height of the nozzle. If leveling the bed automatically provides inadequate results, it is likely that the Z-Offset needs to be calibrated. To do this, use the printer menu and navigate to:

Motion > Probe Z Offset

The printer will auto-home and position the nozzle above the bed. You can then select “Probe Z Offset” again. Use the printer's scroll wheel to adjust the height of the nozzle. DO NOT use the wheels under the bed for this. Use a piece of paper as if you are manually leveling. Once you are done, press the wheel button again, then navigate to:

Configure > Store Settings

to save your changes. You should have the printer re-level the bed anytime you adjust the Z-Offset.

This section is for maintenance tasks that should be performed periodically.