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.
You must log in or # to comment.
I can’t comment on other software since my experience with the commercial options is near-zero. However, specifically in FreeCAD you can do some incredibly tricksy things with sweeps and lofts. I’ve gotten a lot of mileage out of them.
You could create your shape there almost entirely with lofts. A loft takes two or more sketches and you can think of them like “keyframes” in 3D space. Typically you would stack them on top of each other at the specific locations you need, and at the location of each sketch the 3D solid have a cross section of exactly the shape and dimensions of that sketch, and then the shape will be interpolated in the space in between in various ways you can select. The dimensions of each sketch can, of course, be completely parametric and as dimensionally accurate as you need them to be.
The pocket tool is also extremely powerful if wielded creatively. You can knock holes of arbitrary shape and complexity through things, not just circles and hexagons, to any depth. You can create complex three dimensional curves by making a solid of some shape or another, and then making a pocket all the way through it at right angles or indeed any angle. Think of it kind of like a milling machine pass.
Lofts and sweeps and pockets FTW! That does look like the right solution for single objects.
What about objects that sit at an angle relative to each other? Can you define workplanes (sketches) at arbitrary angles? Can you later slide those planes up/down, e.g. to add more distance from the face it would sit on? For instance, in the above object, the holders on the blue face are tilted 14 degrees from the blue base, and the little red holder in front is tilted an additional 5 degrees and lifted 6mm from the front of the larger red holder.
Yes, you can.
You can set up datum planes in arbitrary orientations but in all honesty, I’ve never bothered. You can position a sketch in any orientation, at any angle, at any position in 3D space. You are not confined to right angles of the X, Y, and Z axes.
Sketches used in a loft don’t even have to be oriented on the same plane relative to each other.
I model exclusively with OpenSCAD and a shit ton of math. (Full disclosure, for some of the most absolutely complex things I’ve done, I’ve written Go code to generate OpenSCAD code. But it’s not often that I need that.) And I make some pretty complex things. I’m currently working off-and-on on a 3d-printable mechanical keyboard, for instance.
OpenSCAD, in case you don’t know, is a straight up programming language for doing CAD. It doesn’t even provide you the option to adjust anything with the mouse.
It’s hardcore, but it does the job.
Do yourself a favor and learn FreeCAD!
First, a little plug for [email protected] 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.
