Lack V2 Parts Warping
Hi,
I'm having some major issues with the larger parts of the lack v2 enclosure warping. The smaller parts are printing flawlessly. It seems like the part surface area is a factor, but that the z-height of the parts is a bigger issue. The PSU frame support and lid rack/support printed perfectly flat, but the large "bars" that go under the top lid warped to the point that it pulled the print bed of of the heat bed:
Other large parts are warping in a similar "cupping" fashion, which makes me think that it has something to do with the top layers cooling significantly faster than lower layers that are closer to the heated bed.
I'm printing with 3DXTech natural PETG, but I've also tried Eryone black PETG with identical results. My settings are: 250C nozzle temp, 70C bed temp, cooling fan off, 15% gyroid infill. I have tried more and less infill (10-25%), the cooling fan at 35% for the first three layers and 60% for the rest, 60C and 80C bed temp, and a 245C nozzle temp, but various combinations of those settings all gave slightly worse results. I've also tried brims, which help adhesion if I don't use glue stick, but even if the prints are adhered to, and look flat on the build sheet, they're still warped once they pop off. I also added a hot end fan shield and made a barrier around the printer with cardboard to reduce drafts, but neither of those things made a difference either.
Does anyone have any input on this? I haven't seen much in the way of complaints about these parts warping, so I assume that it's possible to print them with much less warping than I'm getting.
Thanks!
RE: Lack V2 Parts Warping
That is classical warping what you see there. It is of key importance that your part maintains complete adhesion on the print bed till the cool down at the end. If you have even a bit of the corners lifting, your adhesion is not good enough. Brims can help for challenging large parts.
What is the room temperature of the room your printer is located in? The warmer, the better, If it is below 20°C that would explain the heavy warping.
Of course that's not where it ends as you have also found out. Lower infill rate and fewer perimeters should help but at the cost of stability. One thing you might not have tried yet is to put the part diagonally on the print bed, if possible, getting it away further from the edge of the build plate. You can also try a full object height draft shiled around your object, that should also help with keeping the heat better within.
The most helpful thing to do however would be to print with an enclosure. The warmer it gets, the better and let the print cool down completely without lifting or opening that enclosure (wait at least 2 hours, better yet over night). If you have no enclosure a well sized cardbord box which is open only on one side can function as makeshift enclosure. That cardbord box should, together with the desk, fully enclose the printer, also on the top.
If also an enclosure doesn't help, you may need to look for lower warping materials for your setup.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: Lack V2 Parts Warping
What is interesting is that the large prints are staying stuck to the bed, but warping so badly that they pull the print bed away from the heat bed. Glue stick gives pretty incredible adhesion.
The room temp might explain part of the issue, it hovers around 20 degrees but it's definitely possible that it drops lower than that at times. I printed multiple large parts at once, so they were all close to the edges of the bed. If I reprint these I'll have to try to do them one at a time, and with a draft shield.
Once I assemble the enclosure I will definitely try to reprint at least one of the more severely warped parts. I probably should have tried topping my cardboard shield to hold heat in, but I just put it around the printer to protect it from drafts.
Thanks for the tips!