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So far, I have only printed with SLS printers. The results were great, but it was such a horrible mess, and precautions took so much time (gas mask, chemistry gloves, etc.) that I am now switching to FDM.

I would like to ask how I could print the following model:

enter image description here

When you look at this from the side, you notice that there is a gap, and I wonder how I could print this. I am not even sure how I could do this with supports.

As you can see, Cura also marks this region red.

Thank you for your any input how I could deal with this.

But I would like to keep this beautiful angle / gap. Having a totally flat would be my last option.

I have uploaded my model here, if you somebody needs it to estimate how to deal with it.

enter image description here

This is a screenshot of the support that Cura suggests. But I didn't understand it as I couldn't recognize anything.

enter image description here

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  • $\begingroup$ "I am not even sure how I could do this with supports." - Have you tried turning on supports in Cura and looking at the Preview? $\endgroup$
    – agarza
    Sep 16 at 21:18
  • $\begingroup$ Yes, I dit, but I could not recognize what exactely it would do. I mean I saw that it added something, but couldn't make out what it was and if it would work. I have added a screenshot. $\endgroup$
    – tmighty
    Sep 16 at 22:12

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The "typical" angle for overhangs that can be printed without support is considered to be 45°, although some printer/plastic combinations can exceed that value. Your angle appears well beyond 45° and is closer to 90° which requires support.

I have printed models with similar overhangs and the support material creates an unsightly underside. This can be mitigated with a dual material printer, using water soluble filament for the support. I've recently seen videos and images of dual material prints in which the second material (support) was PETG. In both cases, a decent underside can be expected.

Additionally one could use a method promoted by Angus of Maker's Muse in one of his videos.

I have used this method with quite good results. It effectively converts an overhang to a bridging situation.

In your use case, consider that your model is a rounded rectangle. Create another ordinary rectangular prism slightly larger than the main object, perhaps two to four millimeters larger. Remove a shape from the inside matching the main object, but create it in such a manner as to have an overlap of one to two nozzle widths.

Unfortunately, I see that you have a double overhang, as the initial rim is horizontal and the secondary is angled. This would mean you'd want to create a single nozzle width rounded rectangle at the point of the slope change.

The angled portion is going to require support or a substantially increased amount of added-in "crutches" of similar design.

For something like this, I'd recommend a plane cut at the point where the angled surface meets the vertical surface. Create two objects, perhaps add alignment pins and then glue it together.

If you print it in ABS, you can then acetone smooth the result and make the glue joint disappear, especially if it is glued together with acetone/ABS slurry.

sliced frame

sliced frame 2

Images created from OP's model, screen captured via Meshmixer.

The resulting internal faces are perfectly flat, although possibly too thin for alignment pegs.

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  • $\begingroup$ We would need a print bed which itself can rotate. That would solve the problem quite nicely, wouldn't it? If we need to print at a certain angle, the bed would just rotate accordingly. $\endgroup$
    – tmighty
    Sep 16 at 22:02
  • $\begingroup$ I am just fighting my way through Fusion 360. I will try to do it myself :-) $\endgroup$
    – tmighty
    Sep 16 at 22:28
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    $\begingroup$ In the non-hobbyist world, there are 3D printers of many variations, one of which includes an extruder mounted on an articulated robot arm. This allows the nozzle to be positioned in nearly any required angle, making overhangs a non-event. $\endgroup$
    – fred_dot_u
    Sep 16 at 23:15
  • $\begingroup$ Fusion 360 has an easy to use plane cut feature, if you choose that route. $\endgroup$
    – fred_dot_u
    Sep 16 at 23:15
  • $\begingroup$ Thank you! I just managed to do it in Fusion 360 with the help of this tutorial: youtube.com/watch?v=1X9q7Q0J-gA $\endgroup$
    – tmighty
    Sep 16 at 23:51

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