Quick and dirty 5 minutes craft: Draw a rough shape, define the contact surfaces & load, click run, and get the optimized shape. The last step is converting the output to a printable shape and running one more simulation to double-check it is strong enough.

This particular holder is a filament spool holder designed to be loaded with up to 5.5kg of filament (1x2.5kg, 3x1kg).

    • EmilieEvans@lemmy.mlOPEnglish
      5·
      9 months ago

      Nastran.

      Is there any software that does take toolpaths into account?

      Not as far as I know. The next best option is to define anisotropic properties in the z-direction but this doesn’t close the gap between simulation and slicer output.

      How good is it? Good enough. Work with safety margins and temper the print if it is close. An important aspect to make Ansys, Nastram, … work with FDM is experience/rule of thumb. Knowing how to read the result and how to set up a simulation/model to get close enough results.
      Most valuable is where and how it will fail as this is pretty accurate. For the exact load capacity it is the simulation result decreased by some rule of thumb based on experience.

      • IMALlama@lemmy.worldEnglish
        2·
        9 months ago

        Very cool!

        Evidently nastran is headless. Did you use a GUI wrapper/interface? If yes, which one?

        Final question: is this object the typical x wall thickness and y infill part? Did you happen to check the weight of a solid and optimized part? There’s no doubt in my mind that this would save mass if it was a solid part, but if it’s fairly hollow I wonder if the extra walls actually resulted in a heavier part.

        • EmilieEvans@lemmy.mlOPEnglish
          1·
          9 months ago

          Inventor has a GUI for it. There are more options.

          A slightly higher wall count for prints and the weight of the unoptimized solid is pointless in this instance as it starts with a larger slab and tell it to remove x% of weight. With the simulation result you either increase or decrease the x% removed setting and run it again till the load part strength is correct. Very basic in this regard but this was a quick design. How the spool is relative to the mounting points isn’t optimized. It was just me drawing something.

          This particular part is 70g each with the filament being approx. 100mm moved forward (leaver length) and were simulated to withstand roughly 12kg and tested with 5.5kg+spool weights.

  • PlutoniumAcid@lemmy.worldEnglish
    3·
    9 months ago

    I take it there’s another holder on the other side.

    May I ask why the complex shape, rather than just having a triangle with two points on the 4040 rail and the third point being the axle position?

    • marcos@lemmy.worldEnglish
      3·
      9 months ago

      I imagine the “optimized” there means it has the maximum weight support with the minimum amount of filament.

      This shape certainly beats a triangle with only the walls or with just a bit of infill. And it surely takes less filament than one with near to 100% of infill.

      • PlutoniumAcid@lemmy.worldEnglish
        3·
        9 months ago

        I don’t follow you. Look at the photo, the thing is made of triangles. It’s the best shape. So I wonder, why use more than just one? Why make the shape require more than one triangle?

        • marcos@lemmy.worldEnglish
          3·
          9 months ago

          Hum, ok, I misunderstood you.

          Your 1 triangle will need the inclination similar to that middle segment of the bottom side of the piece. I will be huge.

        • beeng@discuss.tchncs.deEnglish
          1·
          9 months ago

          More than likely the static supports used in the software were in the locations you see now,1 for spool and other’s bellow on the rail. They said “draw a rough shape” as a step, so that dictated the shape.

          If the static loads were placed at even height you would end up more triangle like or more of a truss. Depends shown many iterations were used also.

          • EmilieEvans@lemmy.mlOPEnglish
            1·
            9 months ago

            In a broader picture: See it as a demonstration of what all those nice tools in the CAD package can do. In this application with a little bit of thought could come up with a similar or better solution but for an I don’t care design approach the output is already good. A proper design approach would be putting thought in in where to place the contact surfaces relative to the spool and then run this software or go a step further and allow a different software to also change that parameter. Keep in mind those simulations are computationally expensive. Complex/advanced questions might take days to solve while a simple question like this is less than 1 minute.

            The load was in the circle/groove facing down.

            The other constrain was the faces contacting the 3030 extrusion being fixed and a keep-out zone was defined around those to ensure no material there was removed.

            Otherwise, it was just a flat slab as shape.

            What at first surprised me was how this part works: There is a point defined by the lowest/left triangle (tension & compression) on which all the weight rests. The remaining structure is is a cross beam (top mounting point to spool) to support it (tension) and the structure on which the spool rests (compression).