Top layer infill/outer shell glob issue.

[Sendit]

I forgot to take a picture before heading to work. Just try to bare with me.


The picture below is one I got off the internet, the build table is not close enough to the nozzle for the first layer, etc.


What it does, is help explain my problem. When the print head goes to infill operation after doing the outer shell, the head will leave little raised areas or globs when changing direction. These globs are right where the infill and outer shell meets at. I'm thinking it's because of over extrusion. Question is how can I control that, other than tricking the printer in to think it's using a slightly larger OD filament (setting now is 1.74) to 1.75 or 1.76







Is there a way to change the direction in which infills for the top and bottom layers occur? Say the top layer is infill is printing at a 45 degree angle but I wanted 60. How could I go about changing that? With infill it's really easy.

[3dex ltd]

You certainly could control your issue but I think it depends on what slicer software you're using. For example, with Cura I would reduce the flow rate to 95-7%. However (please correct me if I'm wrong) but I don't believe there is a way to change the infill angles at which they meet the outer layer.

Also worth trying... in Cura there is a way to make the infill print before the outer edge (So the printer will print the infill and then the outer edge on each layer). This might help a little bit.

I think it will take some playing around with your slicer.

Incidentally, does the issue happen on all layers or just the first one?

[Sendit]

You certainly could control your issue but I think it depends on what slicer software you're using. For example, with Cura I would reduce the flow rate to 95-7%. However (please correct me if I'm wrong) but I don't believe there is a way to change the infill angles at which they meet the outer layer.

Also worth trying... in Cura there is a way to make the infill print before the outer edge (So the printer will print the infill and then the outer edge on each layer). This might help a little bit.

I think it will take some playing around with your slicer.

Incidentally, does the issue happen on all layers or just the first one?

Yes sir only on the top layer (last layer I believe but I'll have to check). I'm using S3D. I'll looking at going inside to out. Thanks!

[curious aardvark]

looks okay to me.
Can't see any option to change top and bottom layers in simplify3d.

Not sure why you think it's a problem ?

[Sendit]

I snapped some pictures of the top layer last night.

[printbus]

Have you looked at the gcode in a viewer like gcode.ws? Assuming there's bits of infill involved, I don't think what you have is unusual. You appear to have three perimeters on the inside and outside of the ring. If that leaves a gap for the slicer to fill, it'll try to get the printer to add small dabs of filament at the center of the ring wall. My experience has been that it takes a number of things (nozzle temp, extrusion calibration for the actual filament width, extrusion width, retraction settings, print speeds, first layer adjustments, etc.) to be just perfect for the top to come out right, so it rarely does.

[Davo]

Try reducing your infill/perimeter overlap percentage.

[Sendit]

Try reducing your infill/perimeter overlap percentage.

I'm at 20% now. However when I change the number, I don't see any real change (that I can tell) in the tool path viewer window (S3D). It only applys the infill and not the top/bottom layers

This is the correct "outline overlap"? This is not my setting, just pulled the image off google.

Have you looked at the gcode in a viewer like gcode.ws? Assuming there's bits of infill involved, I don't think what you have is unusual. You appear to have three perimeters on the inside and outside of the ring. If that leaves a gap for the slicer to fill, it'll try to get the printer to add small dabs of filament at the center of the ring wall. My experience has been that it takes a number of things (nozzle temp, extrusion calibration for the actual filament width, extrusion width, retraction settings, print speeds, first layer adjustments, etc.) to be just perfect for the top to come out right, so it rarely does.

I have not, I just normally look at the tool paths in preview of S3D. I'll try reducing it to 2 shells. It's how the ring. Temps are 215/100 with swiss nozzles (0.4)mm. Speeds are good for the print not to slow but not fast enough were the printer is shaking it self apart. Going slow mainly for for quality,

[Davo]

I've only used slic3r. My understanding is that infill/perimeter overlap adjusts every layer, whether it's a solid rectilinear bottom/top infill/perimeter overlap, or an intermediate hexagonal infill/perimeter overlap. But I've been wrong before.