Top section of printing without solid wall

[xundefinedx 0]

I'm getting a very weird effect on a particular print where the top section of the part does not have a solid wall, but the part is comprised of diagonal lines going one direction on one side and the other direction on the other side.  The result is that this section is very weak.  I've printed twice and the two prints look very similar.  The part is solid up until a few parts protrude, and at that point it transitions to this pattern without a solid wall.  The conductive composite PLA from Protopasta, but I've printed a very similar part successfully with the same filament in the past.  Any tips or troubleshooting recommendations would be welcome.  Thanks!

[Slashee_the_Cow 438]

That pattern looks like it wouldn't let itself at all well to being printed at an angle (without copious amounts of support) or vertically (at all) but it's really hard to tell based on a couple of photos - could you share a Cura project file (.3mf, get it ready to print then go to File > Save Project) or at least a model file so we can see if it looks printable (in which case we start looking at the printer and print settings) or if it doesn't (in which case we beg and plead with you to change the design).

[xundefinedx 0]

The part is designed to be solid.  It's just not printing solid.   I do not want to print at an angle.  I just want a printed part that matches my design. .3mf attached.

v4.3mf

[Slashee_the_Cow 438]

Ah! Sorry, misunderstood (I'm good at that).

 

I can't help but notice there's a ton of travel moves between model, support, and other bits of model:

Are you having any problems with stringing or anything? If the filament is getting pulled away before it fully sets that could explain it.

 

<looks through settings>

Okay, I think you're accelerating waaaaaay too fast. If I enable travel acceleration settings it defaults to 5000mm/s² which I'm guessing is what it will default to without manually setting it. My Ender-3 V3 SE can accelerate at 4000mm/s² and when I let it do that it's actually pulled parts of the model with it sometimes. And since it doesn't always respect the speeds Cura puts into the gcode, I actually had to turn down the maximum acceleration on the printer's control panel.

 

Your print acceleration is also set to 1500mm/s² for the most part. I don't know much about the specific PLA you're using but it's generally only high speed PLA which is designed to go down properly at that sort of acceleration. And since you're printing at 45mm/s, I don't think it's high speed PLA 😉

 

Personally for my stuff I set the acceleration for all the print moves to 500mm/s² and the travel acceleration to 1000mm/s². It doesn't actually add that much time to most prints (and even if it does, slow print > failed print).

 

<continues looking through settings>

20mm/s jerk?!?!??!?!!?? *does dramatic fake fainting, collapsing to the ground*

For most prints I use 8mm/s, tops. If it's got intricate details or I'm worried about stability, I take it down to 4. Jerk is how much the speed can change instantly on a corner (because in an ideal world you smoothly come to a stop and move off in the next direction, but in the real world that results in a blob in the corner). Higher can cause significant vibrations in the printer (on some printers, so bad you get some layer shift), but it also means that when a printer goes round a corner or finishes a section it can pull the filament with it because corners require a bit more adherence than the rest of the print or else it'll just dragged along by the print head.

 

Okay, that's it for the settings, the rest looks pretty normal. I would like to make a suggestion or two:

• Create a modifier mesh - add a support blocker, move and scale it so that it covers the top part of your model:
  
  Click the Per Model Settings button on the left, set it to Modify settings for overlaps (third option) and increase the number of walls:
  
  This will make the insides of the bits which stick up solid walls instead of having a little bit of infill (without adding extra walls around the main area):
  
  A lot better for adhesion and easier for it to print than tiny bits of infill.
• Support > Support Structure to Tree: Saves you a bit of filament and more importantly, doesn't scar the model by sitting on it to use it as a base:
  
• Walls > Wall Ordering to Inside To Outside. The first part of each layer to go down is the most likely to have problems. Sweep it under the proverbial rug 😉

Hope that gives you some cud to chew on. Hopefully some of it works 🙂

[xundefinedx 0]

Printing with the adjustments you suggested gave a much better product.  Print time was about double, but still reasonable.  There were still some flaws in the walls, but they were essentially solid, and I think the part will work.  Thanks for your suggestions!