Bottom layers warpping mitigations
Hi,
I am printing mostly PLA on smooth bed. With some models I have the typical warpping of bottom layers, when model have lot of straight lines. I know the tricks:
- brim
- Mickey mouse ears
- Break the lines by modifying the model
- Slow down in the straights
- Non-linear infills (like gyroid)
- Non-linear bottom layer (I like concentric and fractal also for looks)
But sometimes, you cannot afford those for various reasons. My opinion also is, that it is basically intrinsic material and technology property, since if you grip the model hard, you will end up with internal stresses (which does not sound great).
So, the question is, what other strategies do you employ?
- Do you use glue or something to improve bed adhesion?
- What settings do you use to slow down? Did you try to localize this setting few bottom centimeters only?
- Any other hidden magic setting?
- Some systematic experience, how it varies with enviroment conditions? (the room is at 20-21C)
RE: Bottom layers warpping mitigations
What do you mean by smooth printing plate? Is that the PEI with the film? Or is it the satin printing plate?
For the PEI printing plate, it is sufficient to clean it with isopropanol. For older ones, it is also good to carefully and evenly “roughen” the film with wet sandpaper.
I also sometimes have the problem with the textured printing plate that the flow rate and line width are as usual, but the line shows under-extrusion.
Here, I helped myself with the Z-offset. This moves the nozzle (as in the example) 0.05 mm closer to the print bed and squeezes the filament more strongly onto the printing plate, so to speak. I usually set the layer height between 0.10 mm and 0.15 mm.
Nevertheless, wrapping can still occur. This happens when the speed is too fast or cooling starts too early. This is not as dramatic with PLA as it is with ASA, for example.
Quick start printing for Prusa XL and Prusa Core One
Comfortable display working height on the Prusa Core One
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RE: Bottom layers warpping mitigations
Quick start printing for Prusa XL and Prusa Core One
Comfortable display working height on the Prusa Core One
Reducing metallic resonance noises on the Prusa Core One
RE: Bottom layers warpping mitigations
Yes, i mean the PEI sheet with film, I suppose...
"Cooling to early" - hmm... Can you elaborate how that would be causing the warping?
RE: Bottom layers warpping mitigations
Yes, i mean the PEI sheet with film, I suppose...
"Cooling to early" - hmm... Can you elaborate how that would be causing the warping?
If you cool the filament too early, for example in layer two, it will warp more quickly. Perhaps the print bed is not clean, the layer height is 0.20 mm, and the speed is set too high.
Quick start printing for Prusa XL and Prusa Core One
Comfortable display working height on the Prusa Core One
Reducing metallic resonance noises on the Prusa Core One
RE: Bottom layers warpping mitigations
Well, the warping certainly starts much later. Probably after the heat from the bed doesn't reach through the model any more.
I was more thinking about the laying process. The different cooling rates of looking stretches, that's clear. But if you would cool the plastic just after it is layed, the shrinkage would be happening only in the latest. That's what you also get, when you print slower.
So, does it mean that even PLA would benefit from heated chamber? Not 50C of course.
RE: Bottom layers warpping mitigations
Well, the warping certainly starts much later. Probably after the heat from the bed doesn't reach through the model any more.
I was more thinking about the laying process. The different cooling rates of looking stretches, that's clear. But if you would cool the plastic just after it is layed, the shrinkage would be happening only in the latest. That's what you also get, when you print slower.
So, does it mean that even PLA would benefit from heated chamber? Not 50C of course.
RE: Bottom layers warpping mitigations
Well, the warping certainly starts much later. Probably after the heat from the bed doesn't reach through the model any more.
I was more thinking about the laying process. The different cooling rates of looking stretches, that's clear. But if you would cool the plastic just after it is layed, the shrinkage would be happening only in the latest. That's what you also get, when you print slower.
So, does it mean that even PLA would benefit from heated chamber? Not 50C of course.
PLA will never benefit from a warmer chamber, in fact it can create problems like heat creep which clogs the nozzle. The best way to control corner warping for PLA is not heat but adhesive. Either that or a specialty bed like the Cryogrip Glacier.
RE: Bottom layers warpping mitigations
I very rarely experience wrapping on a PEI printing plate.
I suspect that you are having adhesion problems on the printing bed itself.
Or it could be because the nozzle is not “squeezing” the filament onto the printing bed strongly enough.
Quick start printing for Prusa XL and Prusa Core One
Comfortable display working height on the Prusa Core One
Reducing metallic resonance noises on the Prusa Core One