maker2
Posts: 142
Joined: Sun Jul 19, 2015 9:05 am

Re: Gaps in Perimeters (Again)

Assume that you are delighted with the build surface and have tried on different areas of bed. Would definitely try stepping down 0.05mm at start of print to ensure a bit of elephant's foot and that everything is properly squished.

If the slicer is really in line of fire then how about checking the G-code on the straight bit?

1) Slice with zone in question over origin so can search in code for moves around X0, Y0;

2) find the perimeters corresponding to the delaminated straight area and note length extruded, Z height and extrusion amount. Should all cohere.

That would at least eliminate S3d (or not).
airscapes
Posts: 403
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: Gaps in Perimeters (Again)

I am going to reconfigure my M2 to print your factory file with Esun white PLA+ can you post the one you want me to print?
gwhite
Posts: 249
Joined: Wed Jul 19, 2017 9:37 am

Re: Gaps in Perimeters (Again)

airscapes wrote: Sun Jul 25, 2021 11:32 am One last question.. are you still printing at 66mms.. if so pleas try 40 just for fun.. wiping melted plastic around a corner at high speed will stretch it out
Yes, but when I printed using your settings (which were much slower), it made no difference.
airscapes wrote: Sun Jul 25, 2021 12:19 pm I am going to reconfigure my M2 to print your factory file with Esun white PLA+ can you post the one you want me to print?
The latest factory file I posted (Left Rear Block Airscapes.factory) includes two identical models, with two processes. The first process is mine, and the second process is yours.

Thanks!
gwhite
Posts: 249
Joined: Wed Jul 19, 2017 9:37 am

Re: Gaps in Perimeters (Again)

maker2 wrote: Sun Jul 25, 2021 12:10 pm Assume that you are delighted with the build surface and have tried on different areas of bed. Would definitely try stepping down 0.05mm at start of print to ensure a bit of elephant's foot and that everything is properly squished.

If the slicer is really in line of fire then how about checking the G-code on the straight bit?

1) Slice with zone in question over origin so can search in code for moves around X0, Y0;

2) find the perimeters corresponding to the delaminated straight area and note length extruded, Z height and extrusion amount. Should all cohere.

That would at least eliminate S3d (or not).
Thanks for the comments. I'm getting good adhesion now, using -0.02 mm Z offset. That gives me a small amount of elephants foot. Increasing the offset won't fix the under extrusion on all the higher layers, it will just close up the gap on the bottom. I'm mostly trying to fix the gaps for structural reasons, so just tacking the bottom layer together doesn't help much.

I'm afraid I'm not very fluent in searching & deciphering G-code. I have S3D 4.0.1 still installed, and can try that later today when my current print job finishes. It's still got about 4 hours to go... I may have time to try PrusaSlicer as well. The test prints don't take very long to run. With luck I'll have results from both experiments by sometime this evening.

If Ver. 4.0 fixes the gaps, it's likely an S3D Ver. 4.1 bug. Of course, given the fast turn around on updates these days, that's bad news...
maker2
Posts: 142
Joined: Sun Jul 19, 2015 9:05 am

Re: Gaps in Perimeters (Again)

If a part of the first layer is not properly "on the bed" then subsequent layers over it will appear "thin" because there is nothing for them to squish down against. They'll also move sideways with the greatest of ease.
gwhite
Posts: 249
Joined: Wed Jul 19, 2017 9:37 am

Re: Gaps in Perimeters (Again)

Thanks! I don't think getting the first layer down is the issue, but I went to take a picture of the bottom, and I made a discovery (or two...).

Here's what the bottom of the print looks like:
Gaps Viewed From Below.jpg
The filament looks like it's sticking down OK, but what I noticed is that the underextrusion & gap are occurring immediately after the start of the 2nd perimeter pass!

I went into Preview, flipped the model over, and examined the same area:
Gaps Previewed From Below.jpg
Gaps Previewed From Below.jpg (18.57 KiB) Viewed 11276 times
The first perimeter occurs normally, with the nozzle going counterclockwise around the opening. At the end, it jumps right and begins the 2nd perimeter. There is a retraction at the start of the 2nd pass, but it's acting like it isn't "unretracting" when it starts printing again, and the nozzle is starved for filament for a significant distance. The third pass starts in the same fashion, and may also be starved for filament.

Not sure what exactly what this means or how to fix it, but the gaps are occurring because the extruder isn't pushing enough filament out once it starts the second (and probably 3rd) perimeter.
gwhite
Posts: 249
Joined: Wed Jul 19, 2017 9:37 am

Re: Gaps in Perimeters (Again)

Just a quick note: Apparently Version 4.0 has no trouble loading a file saved in 4.1. I closed 4.1, and opened 4.0, and it immediately loaded the file I had just been working with. I've got the G-code on an SD card, and will run a print as soon as the machine is available.
maker2
Posts: 142
Joined: Sun Jul 19, 2015 9:05 am

Re: Gaps in Perimeters (Again)

Very interesting. Were there other places on the 1st layer where retractions / immediate restarts occurred to compare with?

And you have 0.2mm of "retraction vertical lift" enabled. Can imagine if the printer had a sticky Z axis /backlash it might not come down again as promptly as the Z axis movement speed of 20mm/s would suggest.
airscapes
Posts: 403
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: Gaps in Perimeters (Again)

This makes prefect sense and why I did not include any of the unnecessary retraction setting you have when I posted the first factory file .. No lift no restart no wipe no force no avoid etc
Just finished my 4th print of your factory and set all there retraction as I normally have it and there are no gaps to speak of. Couple more little changes and will post the file. I ask that you load the file and print without making any changes to it.
Thanks,
airscapes
Posts: 403
Joined: Tue Mar 06, 2018 10:35 am
Location: Philadelphia PA Area

Re: Gaps in Perimeters (Again)

The attached factory file was used to print the part in the attached image. Please load and print without changing anything and see if you gaps are gone. I would consider this part perfectly acceptable, this is FFF and it is far from perfect. The more we try and make it so the more issues we create. The makergear printers are very accurate they don't need a lot of software tweaks to do good work..
No gaps .jpg
Left Rear Block Airscapes NO Major Gaps.factory
(43.13 KiB) Downloaded 257 times

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