Notifications
Clear all

Gradual slope not being printed well  

  RSS
Kraut55
(@kraut55)
Trusted Member
Gradual slope not being printed well

Original MK3S, Slic3r PE 1.42.0, Prusament PLA (the color is actually silver), 0.2 Quality MK3, 20% infill, I did not change any of the other settings.

I am trying to print this item http://www.thingiverse.com/thing:3175416 . This is the bottom of the print
As it slopes gradually upward shouldn't the print be nice and clean (without needing any support)?

Or what did I do wrong?

Napsal : 11/04/2019 2:05 pm
Lichtjaeger
(@lichtjaeger)
Noble Member
Re: Gradual slope not being printed well

With chamfers like this, you have extremely large overhangs in the first few layers. See here.

If you want to have chamfers all around your object I can offer you the following method:

First, add a fillet to the edge. The size of the fillet is "2r - 2*sqrt(r²/2)" (r = radius). Then you can make the desired radius on the upper edge. So the first layers have a stable 45° angle and are easy to print and you have a consistent radius on each edge.

Napsal : 11/04/2019 3:45 pm
Kraut55
(@kraut55)
Trusted Member
Topic starter answered:
Re: Gradual slope not being printed well

It is not my design, I just want to print it.

Napsal : 11/04/2019 10:16 pm
vintagepc
(@vintagepc)
Member
Re: Gradual slope not being printed well


It is not my design, I just want to print it.

The point was you didn't do anything wrong; it's the design that is simply not optimized for FDM. Your best options are to:

  • modify the design

  • Find an angle to print it which keeps the fillet off the bottom of the part (though you'll get stairstepping if it's on top)

  • live with the way it prints on that lower edge.
  • Napsal : 11/04/2019 10:28 pm
    Martin_au
    (@martin_au)
    Reputable Member
    Re: Gradual slope not being printed well

    Another option. Print two slower layers with a low layer thickness using variable infill. Make sure fan is on.

    Napsal : 12/04/2019 12:14 am
    Kraut55
    (@kraut55)
    Trusted Member
    Topic starter answered:
    Re: Gradual slope not being printed well

    Thanks, guys. I'll check if I can get a better result with your suggestions.

    Napsal : 12/04/2019 12:08 pm
    --
     --
    (@)
    Illustrious Member
    Re: Gradual slope not being printed well

    Layer thickness is your enemy here. Use variable layer thickness in Slic3r - and set the minimum in those first few layers. Alternatively, use supports on the bed only. It won't make the bad spots look as good as the good spots, but it can improve sub-optimal designs like this.

    Napsal : 13/04/2019 4:17 am
    Peter in Katy
    (@peter-in-katy)
    Estimable Member
    Re: Gradual slope not being printed well


    With chamfers like this, you have extremely large overhangs in the first few layers. See here.

    First, add a fillet to the edge. The size of the fillet is "2r - 2*sqrt(r²/2)" (r = radius). Then you can make the desired radius on the upper edge. So the first layers have a stable 45° angle and are easy to print and you have a consistent radius on each edge.

    Actually, the video you linked to advised exactly the opposite. The title is "Fillets are sexy, but chamfers are better for FDM printing".
    A chamfer is a straight line/plane. For example, a 45° angle from the x-axis to the z-axis. A fillet involves a radius. It appears you have them backwards.

    Napsal : 14/04/2019 4:42 pm
    Lichtjaeger
    (@lichtjaeger)
    Noble Member
    Re: Gradual slope not being printed well



    With chamfers like this, you have extremely large overhangs in the first few layers. See here.

    First, add a fillet to the edge. The size of the fillet is "2r - 2*sqrt(r²/2)" (r = radius). Then you can make the desired radius on the upper edge. So the first layers have a stable 45° angle and are easy to print and you have a consistent radius on each edge.

    Actually, the video you linked to advised exactly the opposite. The title is "Fillets are sexy, but chamfers are better for FDM printing".
    A chamfer is a straight line/plane. For example, a 45° angle from the x-axis to the z-axis. A fillet involves a radius. It appears you have them backwards.

    Sorry. I'm not a native English speaker. It looks like I mistaken chamfers and fillets.

    Napsal : 14/04/2019 5:19 pm
    Share: