Jump to content
Ultimaker Community of 3D Printing Experts
mechamecha

Top thickness not respected when using adaptive layers

Recommended Posts

24 minutes ago, kmanstudios said:

If your top layer gets the lowest value layer (Say 0.04 VS 0.4) it will need the multiplier because it is a much thinner layer. It will also depend on the percentage of infill and type.

 

Yes, that's pretty much what I said. But that's not the way it should be. Adaptive layers shouldn't be completely ignoring the top thickness setting.

Share this post


Link to post
Share on other sites
9 hours ago, kmanstudios said:

No, that is not what you said. And it cannot be both. Adaptive layers changes the thickness of the layer, ergo, you have to compensate. Cura is not magic, you do have to do some work ya know.

 

If you take into consideration that I'm talking about setting the top thickness in mm, then, yes, that is pretty much what I said. For example, if I have my top thickness set to 1 mm and adaptive layers are calculated to use something like .07 mm for those layers, I need to double (at least) my top thickness setting (therefore, something like 2 mm) to get an acceptable top surface.

 

I'm not sure why anyone would set their top/bottom thickness in layers instead of mm...

Edited by mechamecha
Clarification

Share this post


Link to post
Share on other sites
34 minutes ago, mechamecha said:

 

C'mon, guys, give me some credit here... I set it by mm. If I set it by layers, I wouldn't be posting this.

How we do we know that? People come here all the time and do not state credentials or, in your case, provide full information of procedure. Why take it personal?

 

29 minutes ago, mechamecha said:

If you take into consideration that I'm talking about setting the top thickness in mm, then, yes, that is pretty much what I said.

Now that we know that, it does make a difference.

 

30 minutes ago, mechamecha said:

I'm not sure why anyone would set their top/bottom thickness in layers instead of mm

Specific count and not having to do math......people do things all the time that may not make sense to you or me or anybody but themselves. That is why a better reporting of methodology, specifics as well as screenshots help. We cannot read the forum poster's minds or intentions. That is why @cjs asked a most pertinent question as it solved a bit of the mystery of what you were stating.

  • Like 2

Share this post


Link to post
Share on other sites

I apologize if my replies came across as snippy. I'm not taking any of this personally; I just thought it was kind of funny. I probably should have clarified in my original post that I was merely reporting a bug and not necessarily asking for assistance.

 

But, seriously, if Cura was doing exactly what it was supposed to do (printing 5 top layers when 5 top layers were specified), I wouldn't have posted this. I know this forum receives posts from people with a wide range of 3D printing expertise, but we shouldn't just assume that everyone is new and confused.

 

I do appreciate both of you for taking the time to respond.

 

 

Share this post


Link to post
Share on other sites

This isn't even a difficult bug to reproduce. All you need to do is take a cube, fillet the top surface, then slice it in Cura with adaptive layers turned on. If I slice the attached STL using .15 mm as the base layer height, 0.1 as the maximum variation, and top thickness set to 1 mm, there will be 7 top layers generated, and each layer will be approximately .05 mm thick. That results in a top surface that is approximately .35 mm thick, not anywhere close to the specified 1 mm.

adaptive_layers_bug.stl

Edited by mechamecha
Corrected decimal position in base layer height value
  • Like 1

Share this post


Link to post
Share on other sites

We’re aware of this issue, but it’s not an easy fix. It comes down to Cura engine only receiving the amount of top/bottom layers and skin from the UI, not the absolute thickness in mm or something. To fix it, the way the setting are passed has to be changed, and also the algorithms that calculate the skins and top layers from those values. We’ll probably work on this first when we ever come around to improving adaptive layers. I’m currently not in the Cura team, so can’t give any details on further planning. 

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites
19 hours ago, mechamecha said:

>>snip

 

I'm not sure why anyone would set their top/bottom thickness in layers instead of mm...

Lol I do neither/ both. I decide how many layers I want and then convert that to mm. No I cannot defend that or promote it; it is a bit like eating Weetabix for breakfast, although I can defend that 😎

  • Like 1

Share this post


Link to post
Share on other sites

To add to this.  I realized that on a print that has top layers at different heights, some of the top layers were ok and others were not.  It turns out that some top layers were at near maximum layer thickness and others were at the minimum layer thickness.  You can compensate by adding more mm to the top layer height setting (double or 4 times as much) but then your thicker layers would take up 4 times as much filament... not just the thin layers.  That could add up to a lot of extra filament depending on the object.

Edited by Adam324

Share this post


Link to post
Share on other sites

I think I mentioned this some months back - that the top thickness, set by mm, should be respected.

 

In general, the variable layer heights takes a poor approach - we'd be much better served with an AVERAGE layer height.

 

Every print you either decide not to care, or tweak the numbers again and again and again until you kinda get the behavior that:

 

Respecting TOP and BOTTOM thickness

Enforcing an AVERAGE layer height

 

Those two changes could make the feature a LOT more user friendly and produce better results. It's been beating a dead horse for me, I hope you have more luck with it.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Announcements

  • Our picks

    • Architect Design Contest | Vehicles.
      We're open for entries! - Design and submit your 3D designs of architectural entourage - vehicles - for a chance to win a large filament pack. Presenting an idea, an architectural design or something as big as an urban project isn't easy. A scaled model can really help to get your idea across.
        • Like
      • 14 replies
    • What The DfAM?
      I'm Steve Cox, an experienced engineer familiar with 3D printing. I wanted to share some DfAM guidelines with this community to help and make stronger parts.
      I'm also an Autodesk Certified Instructor for Fusion 360, so many of the images in ...
        • Thanks
        • Like
      • 17 replies
×

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!