What CAD software you use?


  • Moderator

    @whopping-pochard said in What CAD software you use?:

    @Phaedrux said in What CAD software you use?:

    It is annoying when the STL translation service is down and I can't export an STL, but that's pretty rare.

    Unless I’m misunderstanding, right click component name in browser, “save as STL,” no cloud export required.

    Maybe? https://www.reddit.com/r/3Dprinting/comments/9es1xt/getting_an_error_in_fusion_360_about_exporting_to/



  • @Phaedrux Fusion360 does the STL conversion in the cloud. When they are updating their servers, usually on Sundays in the US, saving as STL usually doesn't work. When they finish server maintenance, STL conversion becomes functional again.



  • @mrehorstdmd said in What CAD software you use?:

    I used DesignSpark Mechanical for a few years before I switched to Fusion360. It's about as easy to learn and use a SketchUp, but much more powerful and doesn't turn out bad STL files that have to be repaired before they can be printed.

    Solvespace is an interesting program...

    I've made and printed a few small "artistic" pieces generated using Structure Synth. If you like Open SCAD you'll love structure synth! It's not for modeling real objects, but more of a mathematical sculpting tool that uses recursion.

    +1 for Design Spark mechanical.

    It's apparently a very slightly dumbed down version of an expensive program called "Spaceclaim", offered by RS as a tool to design things using their components (and therefore buy them).

    The only price of freedom is that you have to close the initial RS page on startup.

    I was advised of some custom stl export settings, and it does seem to do really "high poly" resolution in prints (if that's the right way to say it).

    I haven't seen a way to add text to a design with it though...is that possible?



  • @Kolbi so one year and that's it? No renewal?



  • @3DPMicro Oh no, you can renew. It has to be done every year that you want to keep using it.
    Solid Edge is much better on this part, once you get it, it yours for ever-ish. https://solidedge.siemens.com/en/solutions/users/students/



  • @Corexy I had found an ungainly way to add text a couple years ago- it involved generating the 3D text in SketchUp and then importing it into DSM. I rarely put text into designs, but that is certainly one of DSMs weaknesses. It did 99% of what I needed when I was using it a lot, but I kept bumping into that last 1% and finally switched to Fusion360.



  • @mrehorstdmd said in What CAD software you use?:

    @Corexy I had found an ungainly way to add text a couple years ago- it involved generating the 3D text in SketchUp and then importing it into DSM. I rarely put text into designs, but that is certainly one of DSMs weaknesses. It did 99% of what I needed when I was using it a lot, but I kept bumping into that last 1% and finally switched to Fusion360.

    Yes I've heard about that one too. I don't often use txt either, so I haven't bothered.

    I still use DSM to this day, as I'm just not that good at CAD and haven't found all of its uses, let alone its limits.



  • I use Tinkercad or OpenSCAD depending on which mindspace I'm in. I tried fusion but it didn't click. I guess I'll need to look into Structure Synth, it sounds like it's my jam (-;



  • @mrehorstdmd @Phaedrux I'm not 100% sure on the mechanics, but I just turned off my wifi connection, launched Fusion, made a new part, and saved it as STL with no issues.

    If I select File/Export to create an STL it tries to send it to the cloud (and takes a while if it's connected), but if I right click the body or component and select "Save as STL" it does it locally, and instantly, no problem.



  • @whopping-pochard interesting...



  • Fusion will work only for a limited time without internet connection



  • just recalled I signed up to beta test some browswer based stuff, vectray - but didn't impress and now the free options seems very limited.

    reminds me, I haven't tested the browser based fusion for ages!

    yes, fusion will only work about a month or so without talking to the mothership; or that was the limit last i tried at least.



  • @arhi

    Hi,

    One thing I perhaps should have mentioned is that MOI is extensible by the end user if they are so inclined.

    There are users who have added some useful and interesting functionality.

    Just recently I had a question about the behavior of the commands that add dimensions. They didn't work quite the way I expected. I asked on the forum and the author told me I could edit a certain file (java script) and comment out one line. That achieved the behavior I desired.

    I gather that much of the program is implemented using java script.

    Frederick



  • @fcwilt That's pretty neat. I'm glad you brought that software to our attention, it seems well-hidden!

    On the topic of modifying software, Fusion 360 has quite a robust API that can be programmed in JS, Pyhton or C++.

    I have an inclination to make a github add-on for Fusion, so that when projects ar esaved, the data is also captured and reflected in Git/github. I'm not sure how to do it, but I think on git there will just be a .MD file that references the Fusion Team link for the design version, and that gets updated with each commit. Alongside, there could be STL output for comparison and preview on Github, but those are limited to 10 MB. Grrr.


  • Moderator

    @bot said in What CAD software you use?:

    STL output for comparison and preview on Github, but those are limited to 10 MB. Grrr.

    I wish 3MF would just take over already.



  • @Phaedrux said in What CAD software you use?:

    I wish 3MF would just take over already.

    thats not how you spell STEP?



  • Yeah!

    3mF is just an STL in a zip file. PASS!


  • Moderator

    Baby STEPS


  • Moderator

    Does STEP allow for mutli color multi material meta data?

    Since .3MF is just a container format the STEP file could represent the model data in side of it instead of STL. The additions for additive manufacturing in .3MF are what's useful.



  • Yes, STEP has color data, tolerance data, material data (physical) etc.. I suppose it doesn't have "support structure" data, per se, but that could probably be made to work.

    I just tried to look, I do not know if AMF/3MF support "solid" geometry. I'd love to find out.



  • i suppose you could use material properties to assign support matterial and model the support as a solid.

    or just make 3mf work with solids as well as meshes.



  • @bot said in What CAD software you use?:

    I just tried to look, I do not know if AMF/3MF support "solid" geometry. I'd love to find out.

    When you export a solid from FreeCAD to .AMF it triangulates it so I would assume AMF is triangles only (so basically STL's + meta data) as FreeCAD works normally with solids and if it could save solid into .amf it would. I'm not sure but it makes sense.

    I'm not sure why tf microsnot had to be a dealbreaker again so now we have both .amf and .3mf 😞 .. anyhow don't have anything that can export a solid in to 3mf except 3d builder and it originally only works with triangle meshes so I believe .3mf is also triangle mesh container so again stl's + metadata.

    STEP/IGES works for decades for the engineering industry as an interchangeable file format for solids but not many slicers know how to deal with them. Machining CAM tools normally handle them ok, and I believe they would be totally ok for 3d print format as well. The only problem is that you can't handle solid formats on "cpu challenged" devices, and slicing a solid requires complex rendering of the solid that's rather "expensive" compared to a mesh that can be rendered on your watch. I'm not sure if STEP/IGES are protected by some patents, it would not surprise me if they are :(.

    Anyhow if we see how few open source tools know how to properly deal with STEP/IGES that might be the explanation..



  • Great points.

    IGES seems to be more open than STEP.

    STEP is protected, as in you have to pay to get access to the documentation/specifications. However, I do not know if you need to license the use of STEP itself. I think the documents are just $$, like when you have to pay to get the building codes -- you don't have to pay to USE the building codes, just for the big book of them.

    I'm not sure how Subtractive CNC Machines "handle" step. If the machines are GCode machines, the intermediary software likely handles the STEP. STEP-NC based machines, however, get the model data sent directly to the machine itself.

    As for Additive slicing: I know that Merill, the author of SuperSlicer (the PrusaSlicer fork) is thining of ways to implement STEP into his slicer. It involves representing the STEP file on-screen as a mesh, so generating a mesh on file-load or manually create a mesh representation of it. It seems like it will be a fairly big task. I personally think the bigger task will be in working around all the mesh-based thinking that the codebase was built with. We may need to start "from the ground up" to get true STEP slicing.

    That said, Merill had some great ideas on how to USE the STEP once it can be sliced, in terms of generating G2/3 arcs or G5 bezier curves. Basically, offsetting bezier curves is basically not practical, the offset bezier curve can not come close to matching the original curve using anything close to the same control points. However, Merill had an idea to simply take the STEP (likely first break it down into the arc/spline/line elements) and for the spline elements, create a very fine mesh representation of the curve -- finer than the printer can produce. Then, offset that resulting polyline, then fit, as closely as possible, within a specified tolerance, a bezier curve spline to those offset polylines. We could use the original bezier for the external perimeter. The offset beziers will have wildly different control points, but they will be much closer fit than trying to offset a bezier directly.

    (I'm no math expert, but it seems the offset beziers need to be broken down into multiple curves, and approximated. Whatever! They are internal perimeters. The whole point is simply to reduce the GCode footprint.)

    🤓



  • @bot said in What CAD software you use?:

    I'm not sure how Subtractive CNC Machines "handle" step. If the machines are GCode machines, the intermediary software likely handles the STEP. STEP-NC based machines, however, get the model data sent directly to the machine itself.

    They don't. The CAM tools handle step/iges files. But if you look at tools that support STEP/IGES before FreeCAD they almost didn't exist. The few CAM tools for substractive that did exist were either handling mesh only or even 2d drawings only 😞 ... I don't know a CAM tool below 1000eur that suppor STEP/IGES files before the F360 manufacture addon (that I'm still not 100% sure what the licencing situation is). Every other CAM tool expect mesh (STL, OBJ..)

    As for Additive slicing: I know that Merill, the author of SuperSlicer (the PrusaSlicer fork) is thining of ways to implement STEP into his slicer. It involves representing the STEP file on-screen as a mesh, so generating a mesh on file-load or manually create a mesh representation of it. It seems like it will be a fairly big task. I personally think the bigger task will be in working around all the mesh-based thinking that the codebase was built with. We may need to start "from the ground up" to get true STEP slicing.

    IMHO a huge amount of useful work is done by CSG and SCAD libraries that are used for e.g. both by openSCAD and FreeCAD ... I don't know what's the deal with FreeCAD "workbenches", how hard they are to create and maintain but I see there's almost 100 workbenches available for download and for e.g. one is called "cura_engine", I believe it can be used to use cura to slice directly from freecad... I don't see any other CAM workbench but maybe it would be easier to make a workbench for FreeCAD that already have full support for solid's and slice from there than make everything from scratch...

    That said, Merill had some great ideas on how to USE the STEP once it can be sliced, in terms of generating G2/3 arcs or G5 bezier curves. Basically, offsetting bezier curves is basically not practical, the offset bezier curve can not come close to matching the original curve using anything close to the same control points. However, Merill had an idea to simply take the STEP (likely first break it down into the arc/spline/line elements) and for the spline elements, create a very fine mesh representation of the curve -- finer than the printer can produce. Then, offset that resulting polyline, then fit, as closely as possible, within a specified tolerance, a bezier curve spline to those offset polylines. We could use the original bezier for the external perimeter. The offset beziers will have wildly different control points, but they will be much closer fit than trying to offset a bezier directly.

    Dunno what's the right approach here. ATTM there's KISS that has some limited support for generating curve g-code and ArcWelder that uses existing g-code and fits the curves in it.

    (I'm no math expert, but it seems the offset beziers need to be broken down into multiple curves, and approximated. Whatever! They are internal perimeters. The whole point is simply to reduce the GCode footprint.)

    Try ArcWelder, I heard a lot of nice things about it (never tried myself), afaik there should be a cli tool to let it convert existing G-Code without need to load octoprint



  • @arhi said in What CAD software you use?:

    Try ArcWelder, I heard a lot of nice things about it (never tried myself), afaik there should be a cli tool to let it convert existing G-Code without need to load octoprint

    Interesting! Maybe interesting enough to get on with fixing a printer that eat gcode and not .tsk files..:P


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