Alternative way of getting into CAD/3D printing?

October 12, 2024 11:02 AM

I'd like to learn how to design in Fusion 360 (or similar) for 3D printing. I find my learning style doesn't mesh well with typical step-by-step guided tutorials. Are there any alternatives?

In the past I've been successful by having a project in mind and working backwards. This has worked well with software engineering and fabrication projects, but I can't bridge that gap with 3D printing for some reason.

I suspect my projects are too ambitious to start with. I tried designing a complex mount for electronic components and that was far too complicated. I wasn't getting anywhere so the project got abandoned.

I realize that I need to walk before I can run. Any advice?

posted by aeighty to Computers & Internet (6 answers total)

I prefer Onshape for drawing (they have a free tier) but in any case I think you put your finger on where you’re going wrong. Start simple. Ideas:

• Cable organizer
• Pegboard pieces
• Small organizer boxes
• Throwaway jigs for other projects (temporary alignment braces, etc.)
• Replacement of plastic bottle caps, especially “childproof“ ones

These are all built objects that I use in my house daily. (The last is a little tougher, getting that spiral going can be a challenge.)

It was diving in and figuring out how to do these that prepared me for my more complex projects. I also learned a lot about what 3-D printing is capable of and not capable of on the way.
posted by Tell Me No Lies at 12:58 PM on October 12

BTW, the core of 3-D design is very simple: draw a shape in two dimensions, extrude it into three dimensions, and add it or subtract it from the piece you’re working on.

There are some systems that try to skip directly to making 3-D objects, but I would avoid them.
posted by Tell Me No Lies at 1:05 PM on October 12 [1 favorite]

I've seen this question asked many, many times in various forums and the answer is always "build a box." Which is a response that's as annoying as it is useful.

(I have a lot of crooked boxes laying around. They are slowly becoming less crooked.)
posted by stet at 1:05 PM on October 12

You could try grabbing an existing 3D model from online sources and modifying it, first a little, then a lot. Here is an example of a notebook holder in the right file type.
posted by chiefthe at 1:13 PM on October 12 [1 favorite]

You don't design in fusion, you construct. Your design process has to start elsewhere. There are other programs that let you design as you go more intuitively. Oneshape and Shap3r are good examples, but my actual design process happens in Tinkercad, an online tool suitable for like preschoolers. I absolutely hate fusion although I wish I didn't. I can do everything I want to in the progs I mentioned, I rarely need the features that fusion excels in.
posted by Iteki at 2:16 AM on October 13

3d printing turns fabrication skills inside out. You drill a hole with a smaller diameter drill to end up with the right size. With 3d printing, you design the hole with a larger diameter than the right size, because 3d printed holes shrink. For really small/close holes, you probably don't even want a round hole: a hexagon or triangle might be best.

Your 3d printer might not be printing at the right size. Most of them are pretty close now, but older/more homebrew machines can be waaay off. The material you're printing with makes a big difference to the end result. Most designs are sized for PLA, which doesn't shrink much. Printing in PET-G requires looser tolerances, as it tends to be blobby. If you've found a design that assumes ABS, it could be anywhere because ABS is a blancmange.

As for a learning approach:

• Seriously, whatever it is, it's almost certainly on Printables or Thingiverse. It might not be the right size, but someone tried. You might be able to work from there
• Don't discount simple-looking tools. There's a mefite who does incredible things with TinkerCAD
• If software modelling is your thing, you may not hate OpenSCAD. It looks like C, but it's really a static language closer to lisp. It also has some weird limitations, such as not being able to read dimensions of anything you've created. But there are a lot of libraries out there for it.
• You might understand a contraints-based modeller better. FreeCAD is such a thing. You define shapes by constraints (this wall is X mm from that one, these two angles meet at a radius of Y mm, etc) and once you have specified just enough constraints, your shape springs into being.Personally, it gives me nightmares, but YMMV.

posted by scruss at 1:03 PM on October 13