First Layer PETG "Wavy/air Pockets/Bubbling"
All,
I had an interesting issue printing with Black PETG. The material is the Overature brand and I had been printing much of the day without any issues. I have an intergral dryer in which I dried the material @55°C for two hours in advance, then continous when printing. Printed some smaller deigns without issue. Then when I went to print a Sqaure Box, 100 x 100mm the wavyness, air pockets, bubbling started happening. Eventually the material blobs accumulated on the nozzle intil the point that printed had to be halted. First layer .2, @ 240°C
I attempted many fixes that I read here on the forum: (6 times} I tried the Z offset at differing levels, Calibrated Z, Cleaned Textured build plate with Soap water, Alchohol, Acetone. Finally I gave up????? I switched material colors with the same brand, "Red color" same design without any problems with first layer. Note both materials were dry in the upper spool tank with integral dryer.
This morning I changed back to black and reduced the nozzle temperature to 230°C Success? Golly folks it was like night and day the quality of the first layer. Not perfect by any means but appeared as usual. Can anyone comment on this? I mean was the temperature too high the issue? or could there be another gremlin that does not come out in the morning? I guess I am not convinced the temperature was the key.
RE: First Layer PETG "Wavy/air Pockets/Bubbling"
Piling on/+1
I'm beginning to think it has something to do with temperature also since I tried calibrating the crap out of the Z layer settings and although I can't confirm 100% I believe this started happening after I put the printer inside it's new Prusa Enclosure.
My next step will be to try lowering the bed temp by a few degrees to see if it makes a difference but if anyone has any tips that'd be swell.
No real issues with the rest of the print, just the first layer.
Your first layer 'Z' offset is calibrated a little too low.
Cheerio.
RE: First Layer PETG "Wavy/air Pockets/Bubbling"
Hi, ultimately it was too high, I backed off on the Z and it appeared to make things worse so I ended up using the "piece of paper" method where I zeroed out the print head then lowered the Z offset until I could pull out the piece of paper with a bit of resistance.
Prints are now smooth like a baby's bottom, somehow using the wizard didn't work for me as I couldn't quite see the head well enough to judge if it should be lower.
RE: First Layer PETG "Wavy/air Pockets/Bubbling"
...First layer .2, @ 240°C...
...reduced the nozzle temperature to 230°C Success? ...
The problem of wavy first layer is then the amount of material extruded is too high in relation to the layer height. So the solution would be to either reduce extrusion or increase layer height. But what if you haven't changed any of them?
I've had a similar experience when I printed PLA at 250 C instead of 215 C (to get a more shiny finish). 215 C prints fine, 250 C creates waves. I'm not sure if this is true, but I read somewhere on the internet that increasing the temperature causes the extrusion to increase. So I tried printing again at 250 C but lowering the extrusion multiplier by roughly 10%. Print came out perfect.
RE: First Layer PETG "Wavy/air Pockets/Bubbling"
...First layer .2, @ 240°C...
...reduced the nozzle temperature to 230°C Success? ...
The problem of wavy first layer is then the amount of material extruded is too high in relation to the layer height. So the solution would be to either reduce extrusion or increase layer height. But what if you haven't changed any of them?
I've had a similar experience when I printed PLA at 250 C instead of 215 C (to get a more shiny finish). 215 C prints fine, 250 C creates waves. I'm not sure if this is true, but I read somewhere on the internet that increasing the temperature causes the extrusion to increase. So I tried printing again at 250 C but lowering the extrusion multiplier by roughly 10%. Print came out perfect.
After further testing I was mistaken, wavyness could not be fixed with lowering extrusion multiplier. See this thread for trying to troubleshoot the wavyness (when using Silk PLA).
RE: First Layer PETG "Wavy/air Pockets/Bubbling"
I am getting distorted first layers on prints with PETG and PLA (Haven't tried anything else yet)
I have had some good prints. when I had a Mk3 I got excellent prints
there seems to be no persistent Live Z setting,
adding a nominal 'Z' offset in slicer seems problematic.
is there any way to adjust Live 'Z' like on the mk3?