PETG Top Layer Issue

So I've resolved to use PETG for some outdoor prints (was solely using ABS) and after some tweaking ect. I was able to get the prints to come out pretty good except for the top layer/infill maybe?

Attachment 16533

So you'll notice the holes/cracks in the top layer. I've heard this is an issue with PETG and its bridging capabilities but after changing some of the things they say I got it to look A LOT better than it did but I can't seem to eliminate it.

Printer: Qidi X-Pro
Filament: Overture PETG
Bed: Heated @ 80, glass bed
Hot End: Micro Swiss All Metal, heated @ 245 (Temp towers and a few tests at lower temps came out bad)
Slicer: S3D
Print Speed: 40
Layer Height: 0.18
Top Solid Layers: 20
Bottom Solid Layers: 3
Outline/Perimeter Shell: 2
Infill: 50%
Pattern: Full Honeycomb
Ext. Fill Pattern: Rectilinear
Fan Speed: 0 @ first layer, 100% 2 and on.

So with ABS I could print at print speed of 60 beautifully. I had to drop that down to 40 for PETG to come out clean at all. I also had to up that top solid layer but a lot.

Any thoughts on what I can do clear my issue? Thanks!

Make sure Minimum infill length is set to .01, ABS and PETG extrusion multiplier may be slightly different if you dud not calibrate it. What is your infill Outline over lap.. I typically use 14 o15%, PETG should have NO fan. Only time I have found fan needed is making very small tall parts otherwise 0 fan just like ABS
Try rectilinear for your infill pattern. nozzle size? Looks almost like what you get when the nozzle is too larger for the model
Sometimes you get better results with small items when you use only one perimeter, S3D will then fill the gap with single extrude, assuming you have single extrude fill turned on.
Also if that part is as small as I think.. you may want to slow it down and also increase the layer height a bit..

Quote:

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Originally Posted by airscapes

Make sure Minimum infill length is set to .01, ABS and PETG extrusion multiplier may be slightly different if you dud not calibrate it. What is your infill Outline over lap.. I typically use 14 o15%, PETG should have NO fan. Only time I have found fan needed is making very small tall parts otherwise 0 fan just like ABS
Try rectilinear for your infill pattern. nozzle size? Looks almost like what you get when the nozzle is too larger for the model
Sometimes you get better results with small items when you use only one perimeter, S3D will then fill the gap with single extrude, assuming you have single extrude fill turned on.
Also if that part is as small as I think.. you may want to slow it down and also increase the layer height a bit..

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Thanks for the reply!

Min. Infill Length was: 5.00, will adjust.

Extrusion multiply I have not changed, its at .90

Outline overlap is set at 20, will drop it to 15.

Nozzle is .40

Hi. Your final layer is too hot. You should cool your final layer by 5-10 degrees celsius, and consider slowing it down as well. For more on how to print PETG succesfully, you can check out my blog.

Hi!I'm still having some issues with this problem, here is a latest print, temperature is lowered ect.