Labyrinth Gift Box surface finish

[Nicolinux 288]

Hi,

I am printing Robert's kickass gift box (yes, I am a fan of everything this gentleman designs...).

 

• http://www.thingiverse.com/thing:201097
  

 

However I do get some ugly artefacts on the surface. It is hard to call them blobs. They look like the layers interwine and do not line up over each other in some spots.

Print settings:

 

• layer height - 0.2
  
• speed - 40
  
• shells: 0.8
  
• top/bottom: 1.2
  

The model on the right was printed at 230°. The one on the left at 240°. I have also started another print at 205° but got underextrusion (and the artefacts are still there):

 

I went for 40 speed because the model already takes over two hours to print. Do you think it will be worth to try printing at 20 for maximum surface quality?

@Robert: You have printed a few of these models for sure. Any advice?

For the bottom part I used Ultimaker pearl white and for the lid Faberdashery mercury red (awesome color by the way - http://www.faberdashery.co.uk/products-page/print-materials/mercury-red/). Will post proper pictures to thingiverse later.

thx.

 

[Dim3nsioneer 557]

It somehow looks familiar. These are Cura's famous turning points, aren't they?

I have a cylindrical print which looks very much the same. Two things are different for this print of mine compared to other prints I made: it has 0.2mm layers (I usually do 0.1mm) and it is made from Colorfabb filament from last year (with which any kind of blobs are normal on my printer if not printed extremely close to underextrusion).

It might help to increase the x/y-jerk and the x/y acceleration a bit (if possible) as the problem is obviously filament which is too fluid combined with a too slow direction change.

 

[Nicolinux 288]

Thanks for the tip. I tried to snap some closeup's. Maybe the problem is easier to identify:

 

[IRobertI 520]

Gentleman eh? I've been called many things, but that's a first

I've seen these as well and "lovingly" call them STD bumps. I don't know where they're coming from but it seems to be a cura thing. I know I printed something quite a while ago that had these issues so I tried the exact same STL again in KISSlicer and the bumps went away. But it doesn't happen on all parts for some reason. The last few projects I've tinkered with hasn't had it. I don't have any of those boxes left to check I'm afraid.

Honestly I don't know what causes it. If it's my crappy model exports or something inherent in cura. Sorry I couldn't be of more help.

 

[IRobertI 520]

Random thought, if it's related to z-layer change could upping the max Z-speed help?

 

[DidierKlein 729]

I have print this awesome box twice now it's a great gift (evil laugh).

I've just checked on the pictures i did of the first i printed, i have the same stuff but i can only spot it on the lid. I don't have the boxes as i gifted them, but i'll probably print it again.

 

[ian 32]

still have to get around to printing that thing... :-)

Can I ask you Robert.. how did you model up the paths on the side of the cylinder ?

Did you just setup a few dozen planes along the lenght of the cylinder.. created simple box profiles in section.. extrude to next plan and when you had your design.. chamfer all the edges ?

Im just thinking how best to model something like that....

Ian :-)

 

[woofy 12]

I've printed three of these evil, absolutely wicked boxes. The paths are not even on a fixed grid, at least not an obvious one. Just a brilliant design. Like Ian, I'd also be curious how you modeled this Robert.

 

[jonask 0]

could it be that these blobs are retraction points? I would print it with combing enabled.

 

[IRobertI 520]

Well... it wasn't easy I can tell you that. It took me more tries than I care to count to come up with a method that worked the way I wanted... I've re-drawn that damn thing sooo many times.

But in the end it's easy to do, once you figure it out. Cylinder -> Plane in center of cylinder -> sketch the maze on that plane (like the mazes you find in kids books) -> wrap -> 3d sketch + convert entities -> cut extrudes along the paths.

 

[Nicolinux 288]

@Robert: Will try to change the z-speed and print again.

@JonasK: Combing was enabled (default for all my prints).

@Didier Klein: Interesting, I have these spots only on the bottom and not a single one on the lid. But the lid was printed with faberdashery so this might be the reason. Although, I think the lid is far easier to print since it has a flat surface. I am more inclined to believe Dim3nsioneer's explanation. If this wouldn't take so long to print, I'll be debugging it all day. Gotta find another small object that features these spots.

 

[IRobertI 520]

You could sink it into the bed to make it shorter. Advanced tab -> Cut off object bottom.

 

[Nicolinux 288]

You are right! Good idea. Will do.

 

[DidierKlein 729]

@nicolux mine was printed in Ultimaker blue filament.

I have some colorfabb filament i will give it a try when i have some time