Bumpy top layer
Hello,
I have MP4 MM3 and when I print large flat model. it has bumpy top layer.
As I noticed, artefacts are just at last layer. layer -1, seems ok.
I tried slower printing, ironing... nothing helps.
it is default setting 0,2mm speed profile PLA
Thanks a lot
RE:
Hard to say without a file of the project but, if I have to bet, my money would be on warping at the peripheral areas of the model. When this happens the nozzle ploughs across the filament, because the former layer sits higher than it should be.
Could you show us pictures of the bottom of this print ?. Check it against a flat surface and see if there’s any curvature.
Additional questions to understand better the issue: are you printing inside an enclosure ?. which steel plate are you using ? Did you apply any kind of glue on the plate ?.
Large flat models with square corners are prone to warping. That’s why, in these cases, we use help such as adding a brim, using adhesive on the plate and keeping the printer inside an enclosure to prevent sudden changes of temperature. Also, the smooth plate has better adhesion to PLA than the others. When we suspect that warping can be a problem it’s preferable to the satin/textured plates.
Yes, that looks like warping. Make sure the build sheet is clean.
Cheerio,
RE: Bumpy top layer
I'll add that giving your build plate a good solid preheat also helps with warping. One of the things I do routinely is preheat my build plate for 5-10 minutes before even starting the print to allow it to fully come to temp. That has reduced warping from larger projects considerably.
RE: Bumpy top layer
Ok, I did two things to get it OK.
1. I import/export model via Tinkercad (originaly from Fusion)
2. Print PLA as PETG
No more bumping, but I do not know, what helped.
Printing at 85°C plate also helps to stick PLA better. At 60 large model has poped up corners.