How To Create Single Wall Prints? BUG?

[Modified_Gemini 2]

I'm trying to design models as "vase mode".  I model in Fusion360 and my latest endeavor is that a few projects require single wall prints.

 

FIRST. I started off with a .41mm offset, (creating thickness of .41mm because a .4mm thickness will not slice)

So as a .41 thickness, the print head creates the full perimeter yet backtracks to the starting point. Its like watching an rotary phone! Print - rewind - print next layer.

 

After some troubleshooting, I found in the gcode. It turns out that the "rewind" is actually printing that extra little bit of wall. (I need/want this part to not happen)

 

So I've played back and forth so far as getting my model thickness to .40075mm, And the given distance extrudes .08382mm of filament, while it still backtracks extruding .00021mm of filament. 

 

Unfortunately, the minimal loss in filament distance is horribly lost as oozing over the long backtracks and causing prime issues.

 

I have changed multiple settings, over and over, yet nothing..

Possibly I'm in the wrong combination?

 

I have even went to a .4 offset, and even a .39 offset, and selected " print thin walls" and they are quite horrible, not solid or connected.

 

 

I'm using Cura 3.2.1, Fusion 360

[ghostkeeper 105]

This is known. It's a limitation of how Cura calculates these things: Your model outline is inset by half the line width. If anything remains, it is printed with the normal line width. If nothing remains, only the "Print Thin Walls" option may still save you. If two lines overlap a lot, then one of the two will have its extrusion rate reduced to prevent overextrusion. You'll ooze some filament there but hopefully not too much since there is a backpressure from the earlier printed line.

 

In the future I hope we'll implement some sort of minimum extrusion after overlap compensation, such that lines that are reduced to less than 30% of their normal extrusion rate or so will just be left out. That would fix stuff like this.

[burtoogle 513]

Have you tried the spiralize mode that Cura provides? It works pretty well as long as the slope of the sides is not too shallow.

[kmanstudios 1,120]

I am not sure what you are designing, a pic would be most helpful. But, this is how I cracked the spiralize/vase mode print. It may sound silly, but it showed me the basics of how it could work.

 

1. Make a cylinder. Just a plain ol' capped cylinder.

2. Bring that into Cura.

3. Tell the top and/or bottom to have no layers or thickness. This will let the top and/or bottom be ignored. If the top only is ignored, you will have a base in the object like a glass. If the top and bottom are ignored (again, ignored = 0 layer thickness or 0 layers) you will get a tube.

4. Turn on Sprialize mode.

5. Slice: This will allow for Cura to see the thickness of the walls and apply the single wall with no issues.

 

This is a project file with the basic settings I laid out above. The top is 0 layers and the bottom is left at default. The wall count is left at default as Spiralize will overrie that with just one wall. Retraction at layer change is unchecked (turned off) to prevent z-scar from marring the surface.

 

UM3E_A_Cylinder_in_VaseMode.curaproject.3mf

 

As @smartavionics mentioned, as long as your slopes are not too shallow, you can use angles and such without worry.

 

Happy vasing!!

[Modified_Gemini 2]

12 hours ago, ghostkeeper said:

This is known. It's a limitation of how Cura calculates these things: Your model outline is inset by half the line width. If anything remains, it is printed with the normal line width. If nothing remains, only the "Print Thin Walls" option may still save you. If two lines overlap a lot, then one of the two will have its extrusion rate reduced to prevent overextrusion. You'll ooze some filament there but hopefully not too much since there is a backpressure from the earlier printed line.

 

In the future I hope we'll implement some sort of minimum extrusion after overlap compensation, such that lines that are reduced to less than 30% of their normal extrusion rate or so will just be left out. That would fix stuff like this.

 

 

The print thin walls doesn't work, I have tried designing thinner walls and switching to print thin walls, yet it wont slice them. At least I know the issue, ill have to stick to printing a double wall vs a single wall for now, thanks!

[Modified_Gemini 2]

10 hours ago, kmanstudios said:

I am not sure what you are designing, a pic would be most helpful. But, this is how I cracked the spiralize/vase mode print. It may sound silly, but it showed me the basics of how it could work.

 

1. Make a cylinder. Just a plain ol' capped cylinder.

2. Bring that into Cura.

3. Tell the top and/or bottom to have no layers or thickness. This will let the top and/or bottom be ignored. If the top only is ignored, you will have a base in the object like a glass. If the top and bottom are ignored (again, ignored = 0 layer thickness or 0 layers) you will get a tube.

4. Turn on Sprialize mode.

5. Slice: This will allow for Cura to see the thickness of the walls and apply the single wall with no issues.

 

This is a project file with the basic settings I laid out above. The top is 0 layers and the bottom is left at default. The wall count is left at default as Spiralize will overrie that with just one wall. Retraction at layer change is unchecked (turned off) to prevent z-scar from marring the surface.

 

UM3E_A_Cylinder_in_VaseMode.curaproject.3mf

 

As @smartavionics mentioned, as long as your slopes are not too shallow, you can use angles and such without worry.

 

Happy vasing!!

 

 

I'm really not trying to print a vase. Also the model is quite complex, it's about 90% "vase" and the rest are parts that do contain infill. Its just the behavior that's causing issues and messing up prints. you can see what I'm talking about if you slice/print this.

https://www.thingiverse.com/thing:2815078

[kmanstudios 1,120]

13 hours ago, Modified_Gemini said:

I'm trying to design models as "vase mode".  I model in Fusion360 and my latest endeavor is that a few projects require single wall prints.........

Kinda sets the direction of answers So, now I am lost LOL A pic of the model you are trying to print itself would be helpful. I have no idea what that thing you posted a link to would be for other than a stirrup.

[Modified_Gemini 2]

2 hours ago, kmanstudios said:

Kinda sets the direction of answers So, now I am lost LOL A pic of the model you are trying to print itself would be helpful. I have no idea what that thing you posted a link to would be for other than a stirrup.

The model itself is not the issue. Its how cura handles the slicing of single walls. The "Super D" is a single-wall model. When you print it you will quickly notice it fail. Even though in the slicer it looks like its sliced and printed fine. (Atleast in Cura, i have not tried any other slicers)

[kmanstudios 1,120]

8 minutes ago, Modified_Gemini said:

The model itself is not the issue. Its how cura handles the slicing of single walls. The "Super D" is a single-wall model. When you print it you will quickly notice it fail. Even though in the slicer it looks like its sliced and printed fine. (Atleast in Cura, i have not tried any other slicers)

I do single walls all the time, even without vase mode, so I am still lost.

 

Edit: This is a single wall print that is not vase mode.

Edited March 6, 2018 by kmanstudios

[Modified_Gemini 2]

2 hours ago, kmanstudios said:

I do single walls all the time, even without vase mode, so I am still lost.

 

Edit: This is a single wall print that is not vase mode.

Really? Can i ask... What version of cura are you using? What settings are you using to achieve this madness! Lol. This is what it lools like when i print this item.

[kmanstudios 1,120]

Latest version of Cura and I am on a UM3X. That seems to be some weird underextrusion you got going on there.

[Modified_Gemini 2]

2 hours ago, kmanstudios said:

Latest version of Cura and I am on a UM3X. That seems to be some weird underextrusion you got going on there.

I am not under extruding. I stated this in the OP. Can you please print this file because it seems were lost in translation.

[DidierKlein 729]

How does it show in layer view?

 

What i usually do if i see some thin walls don't show up is to play with the line width to make sure it prints.

 

For example i try with 0.35mm then 0.34mm and check the layer view if it prints or not

 

Alternatively (i have not tried this) but you could use spiralize with the per object settings on the part that needs that single wall (design it full for that part), and print the rest in regular (i don't know if it's possible but in theory it should?)

[kmanstudios 1,120]

1 hour ago, Modified_Gemini said:

I am not under extruding. I stated this in the OP. Can you please print this file because it seems were lost in translation.

OK, I have two prints going. One is for 3 days and the other is 4 days, so, no, am not going to print this at this time. If I stopped designing things, and let both my printers work, they would both not stop for a few months. I am trying to help but, cannot print to see what is wrong. I have already shown I print single walls all the time with a post.

 

And, no, there is nothing lost in translation. I just said it looked like a weird under extrusion. So, just going to let others try to help.

[ghostkeeper 105]

15 minutes ago, DidierKlein said:

Alternatively (i have not tried this) but you could use spiralize with the per object settings on the part that needs that single wall (design it full for that part), and print the rest in regular (i don't know if it's possible but in theory it should?)

No, spiralize is global only. Doing it per-extruder or per-object introduces risk of hitting the previous layer that was already printed, since you'd be going down in Z direction sometimes.

[DidierKlein 729]

Oh ok, thanks for the info

 

We really need to be able to do per-objects based on a z-height then

[kmanstudios 1,120]

I took a look at the file in question.

 

It is a 0.5 width manifold wall object. That would give you a basic 1 wall using a 0.4 nozzle. It sliced fine and having printed one wall objects, I do not see an issue with this. I can try and squeeze it in, in between prints, but both of my printers are due for a change in the middle of the night and we will see on thsoe days.

 

but, that is one day on one printer and two days on another printer.

 

Just for kicks and giggles, did you try to rotate the object and do a print in a new orientation?

[darkdvd 975]

I draw the same part with different walls thikness : 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42
CURA is configured to use a 0.4 nozzle with a "line width" of 0.35

 

The object can be print when the line width of the model is >= 0.40

 

Note : "print thin walls" not used.

 

 

When "print thin walls" is used, the object can be printed but not without some problems if you look closely

 

[Modified_Gemini 2]

11 hours ago, kmanstudios said:

I took a look at the file in question.

 

It is a 0.5 width manifold wall object. That would give you a basic 1 wall using a 0.4 nozzle. It sliced fine and having printed one wall objects, I do not see an issue with this. I can try and squeeze it in, in between prints, but both of my printers are due for a change in the middle of the night and we will see on thsoe days.

 

but, that is one day on one printer and two days on another printer.

 

Just for kicks and giggles, did you try to rotate the object and do a print in a new orientation?

I know i sound frustrated but i appreciate your help. But its not under extrusion because that is a print wide issue.. The model is actually .41mm thick not .5mm Also it "looks" like it slices fine. But go into layer view and click the little play button is where the issue arises. It prints like a rotary phone. It prints the main wall of the .4mm and as it backtracks its actually printing that remainder .01mm. That extrusion is so slow that as its "printing" its actually oozing out and loosing prime. And as it raises the Z and begins the next layer it prints air until the chamber fills back up with material. Thats why there is that gap.. In one direction is due to a loss of prime. The reverse direction is like a .01% extrusion that its really no material.

[Modified_Gemini 2]

11 hours ago, darkdvd said:

I draw the same part with different walls thikness : 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42
CURA is configured to use a 0.4 nozzle with a "line width" of 0.35

 

The object can be print when the line width of the model is >= 0.40

 

Note : "print thin walls" not used.

 

 

When "print thin walls" is used, the object can be printed but not without some problems if you look closely

 

Ive done multiple thicknesses, and ive tried the printing thin walls. Even at a .4mm it wont slice for me, with print thin walls it still looks like your .39

Anything under a .4007mm thickness has missing sections. Somewhere over .4007 it starts to slice the walls complete, yet it still tries to print the remainder. 

 

I can print double walls completely fine. Or even a 1mm wall where it prints the 2 walls and has that .2mm gap inbetween thats not printed and i can seperate the 2 walls easily. 

 

[Modified_Gemini 2]

Sorry darkdvd, I misunderstood you earlier. now that I am off my cellphone I was able to see exactly what you were talking about. and its a no-go. Nothing changes for me, I even set the wall thickness to .2mm and it still slices like this with a .4mm thick walls.

[darkdvd 975]

If the nozzle is 0.4 mm, the "line width" default value is 0.35, not 0.4 (and the "Wall line width" is 0.35 too, not 0.4)

 

[kmanstudios 1,120]

Ok, so I guess I am your Huckleberry on this one. I ran out of filament on a print and did ot notice until too late. So, I got to abandone a 3 day print with only 12 hours to go...yayyyyyy...

 

But, no issues with printing this. Default settings for 0.2mm layer height. nothing touched in default settings. Standard brim.....So, it ain't the slicer.....

 

And, I am a Daisy because I did

[ghostkeeper 105]

But while printing, did it make an unnecessary circle with 0.1% flow rate along the wall, like a phone dial? I'd expect that to happen (even though it's not desirable).

Edited March 8, 2018 by ghostkeeper
Clarification that it's not desirable.

[kmanstudios 1,120]

It did go back and forth and not in a single pathway like a spiralize would. But I did not touch any controls. It was a raw slice with nothing but defaults. But, yeah, it was like watching a finger do an old fashioned phone dialer...*zzziiik* tik tik tik tik tik tik tik.......

This is the project file:

 

UM3E_Super_D_-_041mm_Offset.curaproject.3mf

 

Edit: Flow rate, I have no idea about. It just printed purty for me

Edited March 8, 2018 by kmanstudios