Driven by a bit of OCD, I tried to see how well I can level the bed. I went through both manual leveling first and having everything in the green zone, and then rand a couple of automatic bed leveling procedures. I even tried the same on both side of the PEI sheet. I then tried sitting the PEI sheet either firmly against the two pins at the back of the bed, or other softer approaches.
Every single time I get this result, where there is a sudden dip in the top left corner (let’s call that ~ X0 Y220 area). It could be the PEI sheet itself, it could be the heated bed surface on which the PEI sits, it could even be a dip on the Y axis itself.
Debugging this would probably be easiest by having a dial indicator attached and then I have the answer to all of my questions. But before I go through all that procedure, it would help to hear some stories:
is this within acceptable limits?
any past situations like this had some simple quick win solution?
Did you do the manual bed leveling via the printers menu already ? Otherwise I would check the heated bed whether this is flat. People have been complaining about the magnets which are sometimes pretruding and make the heatbed uneven.
Yes. I went through both manual leveling first and having everything in the green zone, and then rand a couple of automatic bed leveling procedures. First I did the manual procedure to give an advantage to the mesh end result.
Your suggestion would fit my resulted mesh. If the magnet in the top left corner is lower then the rest, it might pull the PEI sheet down and give me that particular dip (and vice-versa when pertruding, yes). It can be easily validated by adding one or two layers of tape over that suspect magnet and check if the dip goes away. I guess there is no way to adjust the magnets and they are there for good, right?
Tape over magnets will dramatically reduce their grip. Magnetic field strength decreases on an inverse-square law (IIRC), and any gap is much, much weaker than no gap.
So far, I only had to print a full diagonal. X5 Y5 => X265 Y265 to be more specific (I have the other topic where I cannot hit exactly 270, so I backed 5mm in each direction). It did print fine, it sticked (though it was just PLA), first layer looked (the ends of the diagonal were a bit sparse, the middle was spot on).
I still need to do full bed print to see how well the mesh leveling compensates.
