Vase Mode Seam in Preview

[ThePrintOfDarkness 0]

Applying Vase mode in the slicer I'm seeing a seam in the preview.  I assumed vase mode does no have a seam.  Is there a setting in Cura that overrides or modifies Vase mode that is causing the seam?  I've even saw the seam in a printed part. 

 

I'm using v4.13.1

[GregValiant 1,492]

If there is a seam then Cura has decided that it can't spiralize at least a portion of the model.  That's often caused by something in the model geometry.  4.13.1 is pretty forgiving though.

Load the model and use the "File | Save Project" command and post the 3mf file here.  Someone will take a look.

[ThePrintOfDarkness 0]

Here is the project file.  I assume the model is comes with it?

CE3PRO_250mm All Vase Mode.3mf

[GregValiant 1,492]

Yes, the project file contains the model, all your Cura settings, and your printer including any customizing you did to things like the start and end gcodes.  It's an excellent tool for trouble-shooting.

 

Here is the Cura preview of your model.  This is the backside and you can see down low the white marks indicating the starts and stops where Cura had not yet started to spiralize.  If you look at the rest of the model you will see that these are the only starts and stops.

 

Here it is from the top.  There is the phantom Zseam.  It isn't the problem.  What is a problem is that the loops of the walls no longer touch, and this area will fail and fall inside the model as a modest bowl of spaghetti.

 

Below is the gcode read into AutoCad.  I've erased the front so you can see the area depicted above.  This is not a "cartoon" like Cura shows but is the mathematical representation of the actual gcode moves.  If you squint you can see that there is no seam.

 

This snippet of gcode is from that vase.

1 F2885.7 X117.597 Y176.343 Z53.444 E4088.42483
G1 X114.873 Y176.599 Z53.448 E4089.00723
G1 X112.157 Y176.743 Z53.452 E4089.58618
G1 X109.42 Y176.776 Z53.457 E4090.16883
G1 X106.682 Y176.697 Z53.461 E4090.7519
G1 X103.97 Y176.508 Z53.465 E4091.33059
G1 X101.24 Y176.205 Z53.469 E4091.91528
G1 X98.556 Y175.795 Z53.473 E4092.49324

You can see that the Z is sneaking up a little bit with every extrusion.  That's spiralized and there is no Z-seam.

So when I sliced it Spiralize worked and there would be no Z-seam when printed.

What we probably have is a poor rendering (a bad cartoon) in Cura.  
 

 

[ThePrintOfDarkness 0]

Yes, that top part when it goes more horizontal it fails.  I've been typing to manually edit for some mixed mode printing, spiralize and finish conventional perhaps with some infill?? 

 

Still riding the steep part of the learning curve.

[GregValiant 1,492]

Set Cura up to spiralize the model with a "Pause at Height" at what will be your transition layer going from Spiralize to Conventional.

Leave the  Pause alone and slice the file with a conventional slice.

You will pretty much get the splice info for free.  The "bottom" gcode file will run to the "Pause Command" and from there down everything gets deleted.

The "Top" file you copy everything from the Pause Command to the end of the file and paste it in to the first file.

There will be some lines you don't need (like the Park the Head lines and such).  Just make sure that the E numbers are correct using the G92 command.  If you look closely at the retraction distance and make sure of where the end of the filament is in relation to the end of the nozzle you can get very smooth transitions when going across the transition.

Generally, it's easier to put a solid base under a spiralized upper as there is good support for when spiralize starts.  With a spiral bottom and a conventional upper there can be issues because there won't be any supports and they might be required

Here I've shown a transition from spiral base to conventional top.  The lines that I've struck out aren't needed.  The Z move is important (Adaptive Layers might be a problem) and the G92 E line is already correct.  Practicing on a low model is a good idea.

M83 ; switch to relative E values for any needed retraction
G1 F300 Z49.32 ; move up a millimeter to get out of the way
G1 F9000 X190 Y190
M104 S0 ; standby temperature
M84 S3600 ; Keep steppers engaged for 1h
M300 S440 P1000 ; Beep
M0 ; Do the actual pause
M109 S210 ; WAIT for resume temperature
G1 F9000 X186.551 Y107.89
G1 F300 Z48.32 ; move back down to resume height
G1 F3000 ; restore extrusion feedrate
M82 ; switch back to absolute E values
G92 E611.11561
;LAYER:240
M117 Printing Layer 240 of 278 A Weber Stand
;TYPE:WALL-INNER
;MESH:A Weber Stand.stl
G1 F4500 X189.542 Y149.078 E613.1759

[ThePrintOfDarkness 0]

I made a small test piece ~60 slices starting with spiral transiting to conventional.  I made a couple test prints and I noticed the conventional print at the same Z height printed much wider than the spiral.  Does one method print on center and the other inside or outside?  Is there a adjustment or correction in Cura?

 

 

[GregValiant 1,492]

I never noticed that and I don't know the answer.  When you say "much wider" how much wider are we really talking about?

Maybe @MariMakes or @Dustin has some thoughts on this?

[Dustin 193]

Im not sure on this myself.. Possibly Mariska knows more.
Though this sounds like it might be a bug to take to github?

[ThePrintOfDarkness 0]

On 4/3/2023 at 11:49 PM, GregValiant said:

I never noticed that and I don't know the answer.  When you say "much wider" how much wider are we really talking about?

Maybe @MariMakes or @Dustin has some thoughts on this?

It was maybe 1/2 width offsett, noticeable.  I don't know if it is a bug, probably operator error.

[GregValiant 1,492]

Bug...operator error...model geometry...printer problem...setting issue.  Sometimes it's really hard to tell.

 

I sliced this in Spiralize with a pause at layer 405 and the another slice in conventional.  I see a step there in the preview of the combined files.  It's exactly where Spiralize ends and the conventional top starts.

 

I went back and re-sliced the top at .2 horizontal expansion.  I thought that looked pretty good.

The "combined" file looks odd in the preview.  Turning on the "Line Width" setting it looks like this:

 

There may be a little step left but it isn't much.  You can see by the color change that Cura really stepped up the Line Width on the conventional section as it is colored brown.

My first image is in Compatibility mode which gives a 2D representation of the preview.  In this case I think it indicates that this would print pretty well.  That top still worries me though.  Spiralize just doesn't work the closer a feature gets to horizontal.

This method (splicing files) would leave a seam on the top few layers.  I think I'd print two parts and glue them together.

[ThePrintOfDarkness 0]

12 minutes ago, GregValiant said:

This method (splicing files) would leave a seam on the top few layers.  I think I'd print two parts and glue them together.

Ya, that's what I thinking. I've even contemplated using a 3D Pen to fill in the defect.

 

I'm learning layer height plays a big part, I was trying for 0.6mm.  Pictured is a pure spiral/vase mode with PETG at .28mm layer.  The hole left behind is ~ 4mm.  If only I can get that to fill over.