I’ve made a large number of custom prints, and all of them were created using TinkerCad. It’s an amazing toolkit, stupid easy to use but versatile. That is … until something needs a tiny adjustment somewhere. That’s when I feel it would’ve been neat to use parametric CAD instead.

I have spent many hours following Youtube tutorials for Onshape, Fusion, and FreeCAD. Tutorial shapes like a LEGO brick are fairly easy, although I admit that this kind of modeling is a sharp departure from the kid-friendly TinkerCad.

My problem is that I don’t want to make simple coasters or keychains, but complex shapes like this one. It’s a holder/mount for two different kinds of walkie-talkies that I use, and the blue part slides into a tray in my car’s dash where it sits nice and snug.

Question: How the hell do I even get started modeling something like this?? There’s not a single straight cuboid here. Everything is slightly wedge-shaped.

The way I do this in TinkerCad is that I build the hollow first: I made a 3d model of the walkie, a little oversized, set it be hollow, and drop it into the shape - that’s the red or orange shells you see.

  • wjrii@lemmy.world
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    7 months ago

    First, a little plug for !cad@lemmy.world because more traffic is welcome. The pinned post there is a fairly comprehensive list of viable 3D mechanical CAD suites. I’m a rank amateur with actual designing, but if you want someone to drone on at length about their business models and licensing terms, I’m your guy. (short version: “Fuck you, fuck you, fuck you, you’re cool, and fuck you.”)

    Now then… I also came from TinkerCAD, and I actually think the grouping and alignment tools lifted from vector art programs are super intuitive, and they almost provide a sort of design history if you use them right, but there are so many things that can’t be done quickly in TinkerCAD, and Autodesk also nerfs it for reasons that are commercially sensible but not technically necessary.

    Almost all parametric tools , and also most “grown up” (for lack of a better term) direct modeling tools can do the Boolean addition and subtraction that is at the heart of TinkerCAD’s “solids’n’holes” paradigm, often in a couple of different ways. For instance, to make your orange part there, I’d draw a 2D silhouette of the vertical view, then extrude (or “pad” or “pull”) to the height. Then I’d draw on that top surface, possibly with a reference plane set up first to avoid having the model too far up its own ass (i.e. the toponaming issue), making the shape that needs to be extracted. Then you can cut or extrude down into your solid. Most tools will know what you mean, but some might make you do use a distionct tool or manually do the boolean “difference”. You can then do the same with your hex grid, setting up a new sketch for that. Later, if (for instance) you wanted to have 12 holes or bigger holes, you’d just edit the one sketch. Your red part would be similar, but doing the back of it would involve extruding out from the new sketch. The power of sketch and extrude is, apart from the ease of implementing a parametric history, doing several things at one that would each have to be a manual hole in TinkerCAD.

    Finally, there’s the simple matter of fillets and chamfers, which TinkerCAD doesn’t support as an independent function. Manually adding them gets tiresome real quick and is the “killer feature” that made me realize I needed to move on. Other tools like loft sealed the deal. TinkerCAD is capable of some really interesting parts, but not efficiently.