Table of Contents
Why can't I get a good first layer?
Why won't my prints stick to the bed?
Answer:
Usually a combination of the following factors:
Operator & Setup issues
Follow the setup instructions.
Dirty Plate
Residue from incompatible materials
Clean your build plate when switching between filament types (e.g. from PLA to PETG), or use a dedicated build plate for each material type. Alcohol will not clean the sugars residue on build plates left by PLA. Use a clean ScotchBrite bag with dish soap and hot water to remove any residues. Always leave plate to air dry.
Plate oxidation
Over time the PEI build plate coating and texture can oxidize. Scrub very gently in hot soapy water with steel wool. Rinse well and air dry.
Bad Z Offset
Read about How to set the z offset
Bed Not Level
Level the bed with the SCREWS_TILT_CALCULATE
Stale or reused bed mesh
Use Orca's Direct Adaptive Bed Mesh Compensation. See its docs. Read Adaptive Bed Mesh and How to run a Bed Mesh
First layer speeds too fast
Try slowing down to 20-30mm/s.
First layer speeds depend on filament material and other factors. Speeds for first layers tend to be under 60mm/s and as slow as 20mm/s for some filaments.
More
See Tips for better first layers for additional techniques
Discusion:
Should I used glue?
No. Glue on a PEI bed plate is used to form a separation layer to prevent printed parts from binding to the bed plate.
Glue was used on older types of printers that had glass or other material beds than textured PEI which grabs far sticker than glue. Textured PEI is orders of magnitude more grippy to plastic than glue.
If glue is “working” for you then it's just sweeping the root causes of the poor bed adhesion under the rung and will still manifest as other issues.