The red line is the sensor’s detection line, which is a considerable distance from the edge of the bed.
The area 2-3 cm from the edge of the print bed has no print bed level detected.
Next, watch the following video.
This is a video of interrupted printing of a raft. An 11x11 calibration is performed immediately before.
In the area at the back of the print bed, the filament moves just by touching it with a finger. The filament has not been fixed at all.
This is due to the fact that this is an area that is not subject to automatic level adjustment.
I use rafts for PLA and ABS printing, but the rafts fail to settle and cause warping in the printed material.
The smoothness of the print bed varies from machine to machine, so some may not experience this problem.
I think this is a very unfortunate state of affairs when the hardware is so good and has the wonderful feature of automatic level adjustment.
As far as I’m aware, this is the standard behavior for auto leveling though others on the forum that have experience with more printers may correct me.
As for your issue specifically, it’s hard to see from the video but it seems like the back line that separates from the bed looks the same as the other lines. Is this true, or is it not as “squished” against the bed as the others?
If it does look the same, your problem might be that the bed hasn’t had time to heat up on the edge. Try setting the bed temperature through the touch screen, wait 20-30 minutes for the bed to heat up, then run the print again to see if it makes a difference.
In front of the printing bed, the filament is oval in shape, but at the back of the bed it is round and not pressed against the printing bed. See the picture. You can clearly see that the filament has lifted and is not fusing.
The bed is warmed up sufficiently to allow time to elapse before testing. Also, the printed sheet has been cleaned with alcohol.
In the video, the problem occurs at the back of the bed, but there is also an area on the left side of the bed where the filament has a weak fusing, which can cause a print failure.
Outside of the sensor’s detection line (red line), whether the bed warps up or down can vary from individual to individual. So I don’t think it is possible to correct the level by software prediction. I would like the level sensor to detect the outermost white line of the printed sheet and adjust the level. Even if the white line cannot be detected due to hardware limitations, I would like it to detect the outside as much as possible.
I searched Git for this and found several posts about it. However, the development team has closed it as no problem.
I have also noted this issue below.
The development team will not work on this unless lots of people speak up to raise the issue.
I am eager to see many opinions raised.
Perhaps also still interesting,
as I have reported elsewhere, the heating bed with the screws only tighten when the heating bed has reached the temperature to avoid tension.
So you may not have quite so bad values I heat PLA max with 50 degrees that is quite enough and it sticks super.
So if I want to print I go as follows:
1.print module mount and connect.
2.lay the heating bed on the base plate and put all the Screw in easily.
3.connect the heating bed
4.switch on the machine and heat the heating bed to 50 degrees.
5.only now I tighten the screws of the heating bed on the base plate, then the magnetic pressure plate is put on.
6.now you can start the auto calibration.
Maybe they are then also on the outer edge where not measured the values are better or so good that the pressure then holds.
With other members I have received positive feedback, because you had previously even worse values, maybe that affects them only the outer area!
Possibly your plate is curved upwards in the middle, strained. What then leads to an auto-calibration that in the middle of the height is correct, but in the outer area of the head would have to be readjusted downwards!
But also bobby4718 could be right and or in this area is no longer a heater, which would consequently also lead to the fact that their pressure does not hold there.
It would at least be worth a try, as described above to screw the plate only after heating. Try it out!
If you only 3D print occasionally, such a procedure may be fine. I use it for work; I perform several print runs a day and I can’t get the job done if I have to go through the time and effort described to warm up each time I print.
Whether the edge of the bed is more warped up or down depends on the individual. There is no way that this can be predictably compensated for by firmware.
It is possible that the warm-up will result in the distance between the bed and the head being just right, or that it will be narrower or further apart. Even if it works, it is by chance and there is no certainty.
Currently, there is no problem with filament fusing within the area of the automatic level adjustment. This is even if the printer is printed from cold or used continuously for several hours. If the automatic level adjustment is in place, I believe the printer can be used without the need for troublesome warm-up.
Even if you only use the 3D printer module for the most part, this procedure can be useful for the first start-up, as you do not have to repeat it constantly. Only the first time so it was also meant, but so you come possibly on a better level adjustment since the values are not sooo far apart. As if you simply screw the bed to the base module and simply heat. There is always tension somewhere.
Certainly, the base plate as well as the heating plate should be certain tolleranzen abkönnen and already very accurately manufactured.
Of course, if you print many different filaments with many different bed temperatures on the day, I can see that this makes no sense, but if you print only PLA on one day and the bed temperature is always 50 degrees, this could be helpful!
