Show HN: Space Age Hand Tools in the Maker Age


66 points | by incanus77 103 days ago


  • choonway 103 days ago

    The chamfer in the detail is wrong in your model.

    Section A-A is what you would see if you sliced the part along the dotted line and see it from the direction indicated by the arrows.

    If you cut your part along A-A you would see a rectangle, not a trapezoid.

    edit: did my own model and added a picture for reference :)

    • jacquesm 102 days ago

      You're correct. The shape of the tool is the way it is so it doesn't get wedged at the bottom of the seal groove.

      The part in contact with the old seal is about as wide as the seal, the part in contact with the seal groove is narrower, as it should be.

      The tool as shaped by the OP would get wedged between grime and fragments of the old seal or might cut the old seal because of the too narrow point that only contacts the old seal in the middle or on either edge.

    • incanus77 102 days ago

      So here's a puzzler... I think you are backwards. Based on what I've seen [1][2], the arrows show the direction of sight, so the part would taper towards the inside of the hook. It's not clear how this would be gradual, either, i.e. tapering in two dimensions, so the drop-off would be sudden. I'm still trying to figure this out.



      • choonway 101 days ago

        The original 2D drawings are in first angle projection (inferred). The drawings in your links are third angle (also inferred). This will affect the placement of the section view, but will not change how the section view looks like.

        i.e. in 3rd angle projection, the section view would be on top and not at the bottom of the parent view.

        Hopes this helps to clean up some of the confusion.

        The alignment of the section view is off as well. It should be aligned with the parent view:

        • choonway 101 days ago

          my model on thingiverse:

          I wanted to publish it earlier but had to wait a day before I could publish it

        • incanus77 102 days ago

          Ah! This makes sense, thanks. I will fix & update the post. I guess the placement & orientation of the cross-section hints at this.

      • eggy 103 days ago

        Very nice write up, and it seems like you had a lot of fun.

        I play with OpenSCAD for fun, but because I use Inventor and Rhino at work, and FreeCAD at home, I don't use OpenSCAD to actually design stuff.

        If I want to do generative, creative and coded design I use Racket with the Rosetta package [1] with Rhino or AutoCAD as my backend. I am trying to port Rosetta to FreeCAD [2], so it is all free. Racket with Rosetta is a lot more free or open to creating generative designs than OpenSCAD. I really get a kick out of Grasshopper [3] with Rhino too.




        • linguaz 102 days ago

          > I am trying to port Rosetta to FreeCAD ... so it is all free.

          This sounds really interesting. I've been wanting to work with Rosetta but with a backend other than AutoCAD, hopefully something that could run in Debian. I'd be interested to follow any progress you make on this front if there's a code repo / link you could point to, or maybe message me (contact info is in my profile).

          • eggy 101 days ago

            Rosetta already has an OpenGL backend. My job is not coding, so getting Rosetta to work with FreeCAD is a personal project that I have not gone too far with. If I do, I will create a code repo. I sometimes code in Python for FreeCAD and Blender3D in the meantime. I like Rosetta, since it is striving to be a general purpose geometry-scripting language like Processing did for multimedia arts. Processing has been ported to, and is key to Rosetta.

          • incanus77 102 days ago

            Cool, I’ll check these out. I’ve been conceptually into generative design, but haven’t played around yet. Clearly OpenSCAD will be a huge uphill battle there, if useful at all.

          • mattnewport 103 days ago

            This is cool but I was left at the end wanting to know, did it work?

            • jacquesm 102 days ago

              About as good as a screwdriver would have ;)

              • incanus77 102 days ago

                Yeah, well enough :)

              • m463 103 days ago

                hilarious! This is like the Malcolm in the Middle episode where Hal fixes a burned out light bulb. Search "Hal fixes a lightbulb" and you'll see what I mean.

              • pjc50 102 days ago

                There seems to be a lot of ... "not invented here" going on? It seems there's a determination to reinvent or discover stuff that could instead be learned. Like not having familiarity with technical drawing conventions.

                Doing it all by trig seems like a lot of work too, a good parametric CAD system would have higher level primitives for curves, chamfer, fillet etc.

                • TeMPOraL 102 days ago

                  Isn't NIH essentially how humans learn? While this particular thing could've been made easier in a mouse-driven CAD tool, and a more pragmatic approach still would be to buy an off-the-shelf tool, this looks like a perfect project for someone who wants to get better at using OpenSCAD.

                  • incanus77 102 days ago

                    To an extent, yes. This was a low-risk learning project and I agree that there is value in formally learning the “right way” and not just muscling through (the wrong way, even, sometimes). But this one was just a “quick” side project. I feel like I have a better appreciation for what sorts of stuff I should do upfront.

                    Also, I am gradually acquiring a sense of space, physical effort, and mechanical operation of things in the real world after a long time in software and feeling like I “couldn’t do” these sorts of things. It’s sort of an eye-opener and a confidence booster to even get through something like this the first time, however sloppily.