Z Seam holes

[louis_sckr 0]

I started printing a 4 days print and noticed that my z seam is not connected. It looks like underextrusion but it isnt, as the other layers are perfectly fine.

Any help would be appreciated! The 3mf is not the sliced file of the print. I only have the ufp for the print.                   

UMS3_jet housing.ufp

[Torgeir 268]

Hi @louis_sckr,

 

Something is really wrong here, as this ufp file are almost 140Mb.. Way to big for most of us to upload.

This file probably have to high resolution (a very hi number of points).

 

Thanks

Torgeir

[louis_sckr 0]

Hi Torgeir,

 

yes the file is very complex. It has lots of round edges. Also the part fills almost the whole build area. Decreasing the resolution would also mean less smooth parts I guess. Its already a pain to slice lol.

Still I don't know why the seam wont connect. Or could this be correlated to the file size?

[Slashee_the_Cow 451]

If you could post the Cura project file (.3mf, get it set up then go to File > Save Project) then that would help because it contains your printing settings - just the slice doesn't give us all of that. Also models are compressed in a .3mf so it's probably a much smaller file 🙂 (I didn't even realise you could upload files that big).

 

Though I might be able to spy the problem from the gcode file - make sure Experimental > Enable Coasting is turned off. It looks like it's making non-extrusion travels (the blue bits) leading up to the seam (exactly what coasting is):

[Torgeir 268]

Hi @louis_sckr,

 

Well, I'd downloaded this "monster" file and sure now understand the size..

Took about 8 minutes..

Where are this places it failed to join? Is it at the shaft output, where it's supported?

I cannot see any weak point at the moment. But what version of Cura was used to slice this object?

 

Torgeir

 

 

[louis_sckr 0]

Hi torgeir,

I used latest version of cura.

The place is always on the seam join.

Thanks for helping.

[Torgeir 268]

Hi @louis_sckr,

 

Yes, just found out from the converted gcode file.

Did you check out the tip from @Slashee_the_Cow, -this is a really good tip..

Also, the project file are the thing for us to evaluate in order to see problems.

We do understand this might be some sensitive thing, however, after you saved this file, you might use the settings to make another simple object and send this file to us.

In this way we'll see if we can find any setting issues.

 

Maybe this can be a good alternative?

 

Torgeir

[Slashee_the_Cow 451]

1 hour ago, Torgeir said:

Well, I'd downloaded this "monster" file and sure now understand the size..

Took about 8 minutes..

The size problem is caused by the infill 🙂

There's a whole lot of gyroid in there. Gyroid is curves. Curves are actually a lot of very short, straight movements, meaning a lot of gcode commands.

If a .ufp file wasn't compressed the gcode in that file would be about 450MB.

[louis_sckr 0]

2 hours ago, Slashee_the_Cow said:

If you could post the Cura project file (.3mf, get it set up then go to File > Save Project) then that would help because it contains your printing settings - just the slice doesn't give us all of that. Also models are compressed in a .3mf so it's probably a much smaller file 🙂 (I didn't even realise you could upload files that big).

 

Though I might be able to spy the problem from the gcode file - make sure Experimental > Enable Coasting is turned off. It looks like it's making non-extrusion travels (the blue bits) leading up to the seam (exactly what coasting is):

I just checked, coasting is turned off

[louis_sckr 0]

here is the 3mf

UMS3_jet housing.3mf

[Slashee_the_Cow 451]

Can you point us to where on the model your photo is from?

[louis_sckr 0]

1 hour ago, Slashee_the_Cow said:

Can you point us to where on the model your photo is from?

I don't have my laptop atm but its from the beginning. Basically the first hundred layers. But I guess it goes along the whole z seam.

[louis_sckr 0]

it should be arround here. I switched to triangle infill btw to save space. But it aint that much.

[Slashee_the_Cow 451]

2 hours ago, louis_sckr said:

it should be arround here. I switched to triangle infill btw to save space. But it aint that much.

It reduces the size of the .ufp file by about a third. The .3mf won't be affected by it because it just has the model and the settings.

 

So it's hard to go by some of my usual analyses because a lot of the time they're for printers nowhere near as good as an S3... it's also hard to go through some of my usual analyses because usually it doesn't take ten minutes to slice the model whenever I try a change (I'd open it up in MeshLab and decimate it - reduce the number of faces - but then I'm not replicating your situation).

• It's definitely not coasting - not only do you have that off, but you have the opposite (Walls > Outer Wall Wipe Distance) on. You could try doubling it to 0.4mm and see if that helps (in the photo it's hard to tell if the gaps are on the way from or to the seam).
• There's a bunch of places where it's travelling through a wall, albeit retracted - but if anything that would cause overextrusion.
  
• It's a shame there isn't a sharp vertex you can hide a seam on in a circle.
• This bit does have some unretracted travels right near a seam - there's the potentially it pulls the filament with it:
  
  You can prevent that by changing Travel > Combing Mode to Not in Skin and Travel > Max Comb Distance With No Retract to something low (I went for 1mm):
  
• Now, I could be underestimating what an UltiMaker printer can do (unfortunately the title of "Assistant Moderator" doesn't come with a congratulatory printer), and I don't know what quality filament you're using (since you just selected "Generic PLA"), but your acceleration and jerk values look pretty damn high to me. I've seen slower printers (read: mine) pull filament that wasn't quite set when it zoomed off on a travel, distorting the model. You're not printing very fast but the acceleration - especially the travel acceleration (which you don't have set to control) because your travels tend to be a lot faster than your extrude moves. I got sick of my Ender-3 V3 SE thinking it knew better than both me and my gcode so I set its maximum acceleration values using the printer's control panel (which it does obey).
  • If you force it to retract for the moves it currently doesn't, you probably don't need to worry so much about these, since the nozzle has to pause long enough to retract.
  • Acceleration: I trust UltiMaker printers properly follow the values specified in the gcode, unlike Creality printers. I limit my printer to 1500mm/s² though I tend to play things a bit conservative. Could be worth at least turning on travel acceleration control and turning it down to 3000mm/s² or so.
  • Jerk: It's how much the printer is allowed to change its speed instantly at a corner. In an ideal world the printer would just follow a line to the end, stop and then go down the next one. In the real world, if you did that you'd get overextrusion on your corners. In cheaper printers you need to worry about jerk actually causing vibrations in the printer's frame and making the movement motors skip steps. In this case we're only worried about the material - if it's not fully set and adhered, it can follow the print head (making it cut corners... or get pulled into an abyss of a travel move). In "ultra conservative" mode I set mine to 4mm/s. You don't need to be that extreme. I would try halving the 30mm/s you already have.
• Mesh Fixes > Maximum Resolution. It does not need to be that low. The S3 only has a maximum resolution of 0.007mm anyway. 0.01mm is fine. Shave a little bit of time off your slicing and avoid flooding your printer with gcode it doesn't need because the motion planner knows what it's doing. It's a setting mainly intended for older printers that couldn't keep up with the number of gcode commands to print with accuracy that high. On curves it's an absolute nightmare because in gcode curves are actually a lot of straight lines. The motion planner reads ahead and sees that it's round, so it just knows to do an arc move. The travel resolution really doesn't need to be that low. 0.1mm is fine. You don't need it to travel so accurately you'd need at least a 5x magnifying glass to see that it's not exactly following the model.
  
  Is this causing your problem? Probably not, I doubt an S3 falls into the "older printers that couldn't keep up" category. But it's generally a good idea to save your computer and your printer some excess work.

[Torgeir 268]

Hi @louis_sckr,

 

What to say, -this was really something different.

I did not find any obvious error, but do find some of the protection limitation built into Cura "played" in here.

As I've used the Gcode monitor in S3D, I cold spot some point where the max retraction limit possibly stopped the retraction. When this occur Cura do not retract and leave blobs at those locations. This is to avoid grinding down the filament and "ruin" your day..   This fit very well in your picture of this location, -and there are many more higher up.

 

Most of the setting in here are "engineering" profiles, -and they normally work very well.

In this curved object, there are a high numbers of points to handle and the retraction limitation can be hard to obtain.

I wonder if it might be better for this model to use "randomize" Z location, as this will spread out thous marks and avoiding this "over run" of the retraction limit? 

As the new hiding method are implemented into this version of Cura, this should work well.

 

The pictures are somehow degraded in here, they are very sharp in this size (none of them are more than 450 Kb).

 

Well some pictures:

 

Here is the original file sliced without support for better details.

The green blob line are retraction points. 

 

This picture original sliced without support and infill.

Here the green retraction line do not appear.

 

 

This last picture show the 3 path of inner wall with the start point of outer wall.

 

 

 

Thanks

Torgeir

[louis_sckr 0]

Hi @Torgeir / @Slashee_the_Cow,

I tried increasing the wipe distance with no effect. I also had a look at the stuff you mentioned Torgeir. All those settings wouldnt result in my issues. I would love to see blobs on the seam instead of underextrusion. I also checked for the bowden but thats fixed in place. When tuning off retraction, I got a ton of stringing and overall everything gets messy, but my z seam holes are gone. So it probably is retract related. I can send in a non retracted project file tomorrow if you like. 

I will try printing with another cura version as well. For settings, I guess I have tried everything but feel free to reccomend what could help. It only needs 1layer to check, since all the holes / circles are already non connected. 

Pretty frustrated with that tbh.

[Torgeir 268]

Hi @louis_sckr,

 

The setting I wanted you to change are to adjust  the setting named "Z Seem Alignment", found under the tab "Walls".

But before that, You'll need to got to "Preferences", now select "Configure Cura", then select settings" and mark check box

"Check All". This will open all setting in Cura.

 

Now open the "Walls" menu. The two last selections are for the Z-settings.

Select the second last named; "Z Seam Alignment" having the setting "Sharpest Corner".

The last setting are named "Seam Corner Preference" now selected to "Smart Hiding". (You should investigate in here).

However, try this.

Press the Select box "Sharpest Corner" and select "Random"!

As a result of the above selection the menu "Seam Corner Preference" disappear.

 

But in this configuration the "Z Seam" are randomized and spread around on the object limiting high number of retractions collecting up at preferred "fixed" spot..

 

This should help -I'll think.

 

Hmm, the problem with the hole in the object, mean that there are no filament flowing can occur if the filament are grind down and almost stopped feeding for awhile as -pressure release the feeder decompress.

Maybe reducing the number of retraction setting can help?

 

Here are the setting and the "object" in "Randomized" Z Seam locations.

 

 

 

Thanks

Torgeir

 

Edit: Using another version of Cura "may" make a difference?

         Maybe one that you used with good result before..

 

 

 

 

 

 

Edited Monday at 07:38 PM by Torgeir
More text.

[LePaul 336]

This is an interesting topic since I still struggle with the z seam on some of my prints.

 

I try to rule out the basics - filament dry, slicer flow settings dialed in with test cubes and make sure that is all in order.

 

I don't have wipe or coasting on (defaults) but sometimes wonder if coasting would help lessen the prominence of the seam on some prints?

 

[Slashee_the_Cow 451]

25 minutes ago, LePaul said:

I don't have wipe or coasting on (defaults) but sometimes wonder if coasting would help lessen the prominence of the seam on some prints?

If the problem with your Z-seams is overextrusion (they're a bit lumpy) then it's definitely worth testing coasting. If it's underextrusion then wiping might help, depending how much pressure is left in the nozzle, but still worth testing.

 

Don't forget Slashee's Silver Rule™: Small scall testing is your friend. Make a small print which is pretty much guaranteed to cause the problem and test using that. A lot quicker and less filament used than testing your full size things 🙂

[LePaul 336]

Just now, Slashee_the_Cow said:

If the problem with your Z-seams is overextrusion (they're a bit lumpy) then it's definitely worth testing coasting. If it's underextrusion then wiping might help, depending how much pressure is left in the nozzle, but still worth testing.

 

Don't forget Slashee's Silver Rule™: Small scall testing is your friend. Make a small print which is pretty much guaranteed to cause the problem and test using that. A lot quicker and less filament used than testing your full size things 🙂

 

That's a rule I use a lot, since a majority of my prints are large.  Try a 25% version (or even less if possible) do dial in settings.

 

Coasting/Wiping is one of those things that doesn't seem to get a lot of attention on things like z seam.  We hear a lot about where to hide it but not as much as how to reduce it.

 

[Slashee_the_Cow 451]

Just now, LePaul said:

Coasting/Wiping is one of those things that doesn't seem to get a lot of attention on things like z seam.  We hear a lot about where to hide it but not as much as how to reduce it.

Be prepared to hear a lot more about hiding them because I think Cura 5.9 is adding scarf seams 😄

 

But trying to hide it pointless if you're printing something round, for example. Nowhere to hide. The best way to try and "hide" it is set the Z seam location to random, but then you have a lot of small blemishes instead of one big one.

[LePaul 336]

Just now, Slashee_the_Cow said:

Be prepared to hear a lot more about hiding them because I think Cura 5.9 is adding scarf seams 😄

 

But trying to hide it pointless if you're printing something round, for example. Nowhere to hide. The best way to try and "hide" it is set the Z seam location to random, but then you have a lot of small blemishes instead of one big one.

 

Exactly, if you don't have the wipe/coast/extrusion rate/flow set right, random just aggravates the issue.

 

There's a lot of ways to dial things in prior - if you have a Marlin based 3D printer, you can do the Pressure Advance calibration .  But these are typically things more advanced users would tinker with.  

 

[Torgeir 268]

Hi @louis_sckr,

 

There are something that's make me wonder and this is your picture of the object.

To me this looks like a single wall, or how did you do this print?

Is this just the inner wall?

 

Torgeir

Edited Wednesday at 07:42 PM by Torgeir
Text error correction.

[louis_sckr 0]

Hi @Torgeir

 

its just the first piece, i aborted the print process as this isnt the quality i am after.

At least partly I found the issue. While the bowden tube appears to be fixed in place, it moves while retracting. I noticed, that I still had the old bowden clips installed.

So by increasing the wipe distance and with my 3d printed collet clips, I should be able to compensate until I got new tubes. Any reccomendation there? (preferably cheaper ones as the original. I dont need the transparency)

I also noted that this support structure isnt working. As I dont want tree support, I need a way to tell cura to delete those super long and thin supports while still having soluable support in the holes for dimensional accuracy. 

Support blocker doesnt seem to work. I tried it few times with different plugins and it generates support everytime. Setting support horizontal expansion to zero will just not connect the pillar and have it end in the part. I also need expansion in order to have a good surface for the fins.

 

Thanks

 

Louis

 

Edit: I tried the method using random locations, but this did just spread the holes.

Edited 22 hours ago by louis_sckr

[Torgeir 268]

Hi @louis_sckr,

 

Oh, -too much play on the bowden tube will create a delayed and too little retraction.

This little detail is very important for this function of the printer.

On the test object, there are just one place I'll consider as a hole and the remaining we name as a blob.

So all your blobs are due to a delayed and reduced retraction.

You can cut about 5 mm off the bowden tube (must be cut 90 degrees across the bowden tube), so that the small knives (inside the collar) get "new" plastic to grab in.

This can be done on each side in order to save this print. But in this case, original parts are much better than alternatives.

I'll think this are your "main" problem.

I'd just tested the "support block" function in Cura 5.81 and found no problem.

 

Here is a picture of the object using "Support Blocking" on the 5 high "support towers", but I leaved the "bleeding hole" supported.

 

 

 

Thanks

Torgeir

 

Edited 17 hours ago by Torgeir
Text error.