Gaps between extrusions...

[JohnnyRobot]

Hello Everyone,

It's been quite a while since my last post. Things have been going great with my printer and I'm posting on behalf of a friend.

He's having an issue where there is consistently a gap between two adjacent beads of material. When he prints something the extrusions aren't touching. The outer perimeter/shell can be peeled away easily. It's almost as if he has his nozzle diameter/ extrusion width set too high. (But it isn't, I confirmed.)

I've had my printer for about 2 years now and I felt confident I'd be able to whip it into shape. He was tired of fussing with it so I came over to try and help him. Unfortunately, I only had 2 hours to help him and I couldn't figure it out in time, I'm actually really confused by this...

Here's what I tried:

-Leveled the print bed - It wasn't too bad
-Set extrusion width to actual, as measured by digital caliper
-Set first layer width to 175
-Reduced first layer Z height from 90 to 75
-Experimented with different extrusion multiplier values - from .90 - 1.20!
-Confirmed correct filament width

I've attached some photos, and the factory file for his print. Any ideas?

Ironman.zip

(12.1 KiB) Downloaded 320 times

[Jules]

Yep.

1. His bed is too far away from the nozzle for the first layer. Have him reset the Z-stop or move the bed closer using the Z-Offset. (Better if he re-sets the Z-stop first.)
2. Do the Z-Offset height calibration as well as the width calibration, after he re-sets the Z-stop. It's just as important as setting the correct extrusion width.

http://www.forum.makergear.com/viewtopic.php?f=8&t=2193 (2nd post)

3. Go ahead and increase the first layer height to 100%. Generally one sets that a little larger than 100% if there is a low spot somewhere in the glass, but lowering the value to 75% is just exacerbating the problem. (Make sure when you do the Z-Offset calibration that everything is set back to 100% values, widths and heights.)

[Bratag]

Yep.

1. His bed is too far away from the nozzle for the first layer. Have him reset the Z-stop or move the bed closer using the Z-Offset. (Better if he re-sets the Z-stop first.)
2. Do the Z-Offset height calibration as well as the width calibration, after he re-sets the Z-stop. It's just as important as setting the correct extrusion width.

http://www.forum.makergear.com/viewtopic.php?f=8&t=2193 (2nd post)

3. Go ahead and increase the first layer height to 100%. Generally one sets that a little larger than 100% if there is a low spot somewhere in the glass, but lowering the value to 75% is just exacerbating the problem. (Make sure when you do the Z-Offset calibration that everything is set back to 100% values, widths and heights.)

I always have my first layer set at 107% width and 107% height. I probably don't need it but it guarantees me a nice solid first layer. Obviously for those small items where accuracy is key I dial it back to 100%.

[Jules]

I always have my first layer set at 107% width and 107% height. I probably don't need it but it guarantees me a nice solid first layer. Obviously for those small items where accuracy is key I dial it back to 100%.

After Jin explained that you can use the first layer height to get around that blasted bug in S3D, I've gone around to all my current working profiles and set them to 101%. Fixed it!

But for the calibration it needs to be at 100%, something that i forgot to do more times than i care to admit.

[JohnnyRobot]

Wow, that's totally different than how my machine runs. I have my first layer height set to 50% and my first layer width set to 145% - It's been working great for months. Perhaps I level on the high side.

He does have some additional questions/comments though...

-The gaps between the extrusion are not present in the skirt.
-Infill seems to be fine.
-The issue continues far beyond the first layer. For example, the shell of a cube is very easily peeled off. "Princess and the Pea" scenario?

[Jules]

Wow, that's totally different than how my machine runs. I have my first layer height set to 50% and my first layer width set to 145% - It's been working great for months. Perhaps I level on the high side.

He does have some additional questions/comments though...

-The gaps between the extrusion are not present in the skirt.
-Infill seems to be fine.
-The issue continues far beyond the first layer. For example, the shell of a cube is very easily peeled off. "Princess and the Pea" scenario?

Interesting.....i didn't know it could work that way. By under-extruding on your layer height and compensating for it by over-extruding on the width, it all balances out. (Don't you wind up with a sharp little skirt attached to the print that has to be filed off though?) Not knocking it.....as long as it works for you, it's cool.

Your friend needs to narrow the gap for the first layer. There is a "How To: Guide to Getting Started" in the Getting Started section now that lists the steps for calibrating, and getting the gap correct, and discusses what the issues are that people frequently see. Perhaps he should take a look at it. (Particularly the calibration and the troubleshooting sections.)

viewtopic.php?f=8&t=2778

-The gaps between the extrusion are not present in the skirt.

No idea why. I've noticed my skirts tend to be smeared a little bit more than the prints too. Might be an S3D thing.

-The issue continues far beyond the first layer. For example, the shell of a cube is very easily peeled off. "Princess and the Pea" scenario?

If the gap is set correctly, you can print with 100% layer height and 100% layer width, and have it attach perfectly every time. But that first layer is absolutely critical. It's the foundation for the rest of the print. If it is off, the whole thing is going to be off.

It just makes things so much easier using these machines if you take the time once to set that gap correctly. The results will be much more consistent.

[Pekish79]

Skirt usually tend to be more squished by S3D or extrude more material because usually is single layer i am sure S3D has some special extruding command for it
i think i notice the skirt beeing slightly flatter usually then the normal first layer

the base on the other hand is always 3-4 layers (or it should be) so it's solidity is given by layers