I’ve had success with large eSun PLA+ prints. But it took quite a few tweaks. Here’s a list of additional things to try (no reason not to do them all):
Print settings
- Print bed temp at 65ºC
- Print temp at 225º for the first layer, then decrease to 220º
- Disable both the AUX fan and the chamber fan
- Keep the top and the door closed. You want the chamber to be warm.
- Print a 2-layer brim (try this last)
- Wet sand the PEI plate with 1000 grit wet-or-dry paper, flush thoroughly, then clean with 99% IPA and a microfiber cloth. (Buildup on a PEI plate requires something abrasive to remove it - it will not wash away or dissolve with solvents.)
- The cold plate with PVA glue (in this case, better than the liquid BBL glue in the green tube) is perhaps a better alternative than the PEI plate in this case. Note: I had such good adhesion on one big print that it pulled the plate away from the bed!
Model Changes
- Reduce the number of solid top & bottom layers
- Reduce the infill percentage (both of these increase internal stress - PLA will always shrink when it cools). Use the smallest % you can without affecting the surface area.
- Change the infill pattern to one that creates less stress in the warping plane. Support cubic might work well, as this is pretty sparse at the bottom and only starts to get denser when getting close to the surface.
- Since your model will be glued together on the bottom, you can reduce stress on this layer by creating pockets on the base that will decrease the surface area.
Hope this helps!