I thought I would knock some dust off my drafting skills after a small chat with @[email protected]
Seeing this image on the tutorial made me realize, FreeCAD seems to be a Technical Geometry Super-Suite. It makes sense that CAD would grow to include all of these things. But I thought sharing the initial perspective of some one who hasn’t looked at this stuff in about 18 years might be interesting.
Granted I’m not actually familiar with most of this stuff, and none of it from the POV of FreeCAD. If this can deliver 10% of what I’m looking at, I’m in for a treat.
Seems like a good opportunity to ask if anyone can recommend learning materials for FreeCAD? Used Solidworks and AutoCAD in school but fell back on tinkercad for a recent project just cause I didn’t have time to invest in learning.
Yeah if you want to be reductive about it, FreeCAD is a GUI wrapper for OpenCASCADE, its CAD engine. FreeCAD is designed to be extensible; the workbench system allows for several different workflows, and using the Python API it’s not that far out there to make your own workbench for specialized tasks. You could build a clockwork workbench if you were interested in designing escapements and such.
The tradeoff is it can seem overhwelming because there’s a LOT of functionality in there. I do almost all of my work in the Spreadsheet, Sketcher and Part Design workbench, plus the A2Plus assembly workbench from the addon manager.
Yeah OpenCASCADE is amazing because it’s the only real geometry kernel that’s open source. There’s a few smaller ones like solvespace, but they’re really more like toys. It’s like the Linux of the CAD world.
Writing a geometry kernel is a monumental task, not unlike writing a real os kernel or a modern web engine. I’ve seen people just lay the basic foundations of a kernel as their PhD thesis. Most of the commercial ones were written decades ago and are still being worked on - the big ones are Parasolid ACIS, ShapeManager, CGM. The last one would maybe be considered a newcomer cause it’s only 15-20 years old.
I just thought in hindsight, my response to you plugging freecad is funny.
It’s like you took me into your workshop with all these benches, and I just point at the openscad bench like a caveman and grunt “scad”.
Yeah somehow I never hitched horses with OpenSCAD; like I can’t imagine designing a table or cabinet purely through code. Using the Part Design workflow can work a lot like how tools work, lay out the location of the feature, draw the profile of the feature, then do an additive or subtractive operation to create the feature…the design process in basically any similar CAD package becomes a dress rehearsal for the build in a way.
That makes total sense. I was on my way to mechanical engineering when I was learning autocad and autodesk mechanical desktop if you remember that. Now it’s just in autocad. (I guess that’s an example of how things used to unshittify. I bet adobe would bring back MD as a separate product nowadays.)
So if you try to enter woodworking after that experience, it feels right to model projects like that. I had learned a lot of coding by this point. So adding the code into parts for flexibility felt great.
This is going to sound complicated. That’s because I bet you can do this with one click. But I thought it was cool I model a compound mitre angle for a cut using numbers I calc’d on Octave (matlab-like foss). Since I’m just a tinkerer, I could only imagine how powerful that could be for pros. Lots of “where was this when I needed it” thoughts.
Needs a better logo as well
Actually that’s a great place for some “I want to help but I don’t know computers” people to jump in.
Yep, there’s a ton of great Foss projects that have a shitty logo. Look at Octave, looks like something 10yo me made in MS paint in 5 min
Logos, GUI, names…
Hey now, naming things is in NP-hard.
Do they have editable history yet? That’s a big blocker for me jumping.
There’s basically a tree of operations that have been applied to a model. At any point, you can go back and edit what you’ve done at a previous step. For example, if you padded a feature out 10 mm, then added more stuff onto that feature, you could still go back and change that padding operation to 15 mm.
I’m still super new to freecad, and I haven’t done anything too complex in it yet, but my understanding is that some types of those changes can result in the topological naming problem. The way I understand it, when you make a shape, the software numbers all of the segments, vertices, and faces. If later changes are applied to those numbered faces, etc, and you go back and redo the operation that made those faces, etc, in a different order, the numbering will be different, and it will break your model.
There is a fork of freecad that fixes that whole issue, but the fix hasn’t been implemented yet in the main fork cause it’s pretty foundational to the working of freecad, so there’s a lot of things that can break
If you just attach every object to the global coordinate system instead of each other that bug can’t happen. Could be less convenient for larger projects though
I was disappointed not to see one. That’s not a ‘no’, but I did look for one.
Further define “editable history?”
I use Fusion 360 primarily but it is available in other CAD software, this is a decent description:
Timeline and Rollback: The timeline in Fusion 360 visually represents the design history, showcasing the sequence of features and operations. You can review, reorder, and modify design steps using the timeline. The rollback feature allows you to return to a specific point in the timeline and make edits, facilitating design iteration and exploration.
It has made working on interactive designs significantly easier for me, and saves a tremendous amount of time and effort.
Ever used photoshop with an undo history? It’s particularly nice for text based commands.
My architect so poked at it for a bit and quickly gave up.
That part at least isn’t suited to its target audience apparently.
I don’t mean to poo poo FreeCAD the way I say this, but the vast majority of those features listed are bog-standard cad suite features at least by modern standards.
I’d love to see a FOSS cad suite kill my personal dependency on proprietary solutions, but as best I’m aware the UX is still hugely lacking.
Does FreeCAD handle aerodynamics? A decade ago I wanted to screw around with low-speed airfoils, and couldn’t find any better indications than ‘OpenFOAM and good luck.’
