Hi everyone. Like many others on here I have had problems with edge lifting on larger models. For example:
Now take a look at the bed temperature:
My target bed temp is 55 degrees C. As the extruder is working where the thermistor is the measured bed temp surges up over the target and the heater turns off. As you can see on the first layer it remains off until the bed temp comes back down under 55 which is almost 2 minutes later during which time the bed has cooled considerably and the edges start to lift.
So if you are having edge lift problems try not to position objects centrally over the thermistor to see if it helps you.
You might try moving your project away from the thermistor.
I have found that printing with a brim will sometimes stop the lifting as well.
Make sure there is no draft blowing on the bed.
I am finding on larger prints the front edges lift but the rear does not, this is a 190mm x 190mm 4mm print.
Does anyone have this problem and know how to stop it. I am trying kapton tape at present as blue tape seems to lift off the mirror at temperature.
I am now also trying cooling using the fan manually and going the opposite way with the bed lowering the temp, I use only PLA and heated bed is not necessarily a requirement from what I gather.
Larger brim, hotter bed, and if blue tape doesnt do the job for you, try printing on glass thats coated with hairspray.
If you think the hairspray is a joke, a few days ago I had to replace my glass after I pulled shreds of glass from it while brute forcing the removal of a piece. Admittedly, I overdid the hairspray coating and I didnt wait for the bed to fully cool down as the print was ruined anyway. But that the bond was stronger than the glass itself, tells you something.
Exactly what I get. The piece in my photo was at the front - the other half of the box was at the rear and didn’t lift. As I said I think it’s down to the bed cooling down to much while the heater is off, and for some reason the front cools faster. I’m toying with the idea of using 4 thermistors spread over the bed in a series/parallel circuit to try to measure overall average temperature instead of just the center spot to see if that cures it.
I have done multiple prints now using PVA glue mixed 1-2 with water on glass,( 2 water, 1 PVA) heated bed to 60c which also helps in keeping the bed amply warm and use a raft. Can’t believe how fantastic the prints are, no warping on 190 x 190 4mm print.
Clean the glass first and brush on the mix, heating the bed dries the PVA mix then print away, let the bed cool properly to remove the print and wash the glass under water to dissolve the PVA and start again.
Not tried hairspray but I heard this is also a good solution
I’ve solved reducing the height of first layer with calibration of bed height…
You will lose the first layer height (few microns) but you will improve the adhesion of first layer…
For some prints I’m sacrified almost all first layer height to have a very strong adhesion, if you use a glass on the bed you will note the formation of slight film of PLA with trasparency proportional to bed height…
My opinion, the adhesion is very good with thi procedure because there is a slight additional mechanical pressure (with temperature) of extrudate on bed.
But clean always very well the bed and raise the temperature bed as already suggested.
If also this is not enough, you have to modify some parameter of slicing, fill density (less dense), fill pattern (honeycomb is very good), solid layers number, ecc (deformation is due to the retraction of material with cooling, so less wires pull, less deformations problems you have).
