gwhite
Posts: 206
Joined: Wed Jul 19, 2017 9:37 am

Re: Gap Fill Issues

Tue Jul 20, 2021 4:40 pm

Ok, I put a brand new spool of eSun PLA+ on the printer to eliminate any filament moisture issues. I did a calibration cube, and actually left the extrusion multiplier slightly high. I should get a 0.40 mm wall thickness, and I'm getting between 0.41 and 0.42 mm. I pruned my model down to speed up testing, and here is the result:
Gaps In Walls 2.jpg
I still have significant gaps between the perimeter passes. This section is a couple mm thick, so the gaps are on all the layers in exactly the same locations.

As promised, here's the factory file:
Perimeter Gap Test #1.factory
(43.29 KiB) Downloaded 8 times

gwhite
Posts: 206
Joined: Wed Jul 19, 2017 9:37 am

Re: Gap Fill Issues

Tue Jul 20, 2021 4:53 pm

Before I printed the test above, I ran a test to fine tune my retraction & extra restart distance. I set up a 3 by three grid of models, varying the parameters up & down slightly. To do a fast check, I only print the lower 5 mm of the models, which results in a 2.4 mm thick ring. With a 0.41 to 0.42 mm actual extrusion width and telling the printer it's 0.4 mm, there should be NO gaps, without any need for fancy extrusion width adjustments or gap fill.

Here is a photo of the model that came out the best:
Gaps In Walls 3.jpg
I still have gaps.

I stripped the S3D file down to just this model & process settings, and here is the factory file for that:
Perimeter Gap Test #2.factory
(14.9 KiB) Downloaded 9 times
There have been lots of reports of this issue going back years, including more than just this one from me. Some users have reported testing their models with other slicers, and they don't have this problem. If nobody can spot a bad setting in my process, I will have to try to print the part in PrusaSlicer. I'm no where near as comfortable with PS as I am with S3D, but if they don't come out with an update of some sort that fixes this, I may have no choice.

airscapes
Posts: 374
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: Gap Fill Issues

Wed Jul 21, 2021 8:47 am

I did not print this, I don't have a .35 nozzle on my M2 atm and don't feel like changing it. I also don't think I have any PLA on hand.
I altered the setting in the manner in which I would probably print this. I don't know it's purpose so not sure about finish quality but I am not big on trying to make 3dprinted parts look nice.. To me it is more about function fit and strength.
I don't use PLA if I can help it, it does not flow like ABS and tends to leave crud in the nozzle unlike ABS and PETG. Make sure you clean your nozzle with cleaning filament.. I even have a .275mm drill bit I slide in the hole as the cleaning filament is being extruded.. not that easy to do but kind of needed with PLA in my experience.
Anyway, see if this works any better for the gap issue, I expect the finish may not be as nice.. Again v 4.01, preview looks fine..
I guess if I wanted the top layer to be all single extrudes I would add a second process to do 3 perimeters for the last 2 layers.. I have found that using all single extrudes to rather than the rectilinear is never as strong unless I am using a .75 nozzle and only need the 1 perimeter and 1 single extrude fill
Perimeter Gap Test Airscapes.factory
(14.92 KiB) Downloaded 8 times

gwhite
Posts: 206
Joined: Wed Jul 19, 2017 9:37 am

Re: Gap Fill Issues

Fri Jul 23, 2021 9:44 pm

Thanks! I've got this on the printer now, and I'll report back in the morning. I've tweaked the extrusion multiplier & temperature to try to address a stringing issue. I'm printing one test model with those settings changed in my original process, and one with all the changes you incorporated in yours.

I tried tweaking the model. The place where I'm having problems is where I have a 2mm wide border. I've got a 0.4 mm extrusion width, so it should come out just fine. I shrank the border to 1.9 mm on the theory that it would help to mash things together & hopefully get rid of the gaps. No cigar...

Update: The new process settings didn't help. I just finished adding a lengthy reply with photos, and the forum software blew it away. I will re-post later today, but I'm going to move this to the Trouble Shooting forum, where it really belongs. I initially replied to another user's post about the same problem, but I didn't notice that it was in the General forum.

To be continued...

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