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Comment by arthurcolle | Hacker News Reader

What is the process by which one goes from a cad file to actually something that can be 3d printed?

I recently got a new ipad pro and got this app sketchr3d and I was blown away by how intuitive it is to design really sophisticated structures. I tried blender on and off like 4 times over 5 years and found it basically impossible to use.

After making some really cool designs in s3d I started to wonder how easy it is to just print it with some kind of decent 3d printer model.

Is it really plug and play/drag and drop your file?

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I didn't use Blender, but the way I understood it, it is more like modelling. Opposed to that, Inventor is technical drawing.

E.g. I could: Draw 2D plane 10x10 mm; extrude; on one surface, create a diagonal helper line; put three circles on that line; define diameter of one circle to be 2.5mm; constraint diameter of the other circles to be equal to the first; split the helper line at every circle intersection; constrain all line segments to be equally long - now all things are fully constrained. Negative extrude the circles (e.g. make holes into the first volume).

Should produce something like this:

   *---*
   |o  |
   | o |
   |  o|
   *---*

You can now change values (e.g. make the base plate 20x50mm and adapt the diameter to 4mm) and the program will keep rearrange everything according to the constraints, if possible.

(I don't have a 3D printer but I have been reading up on it recently.)

As sibling comment says, the design is saved as an STL file, a format they all use, which basically describes the shape of your print in a (variabally sized) load of triangles.

However, most use 'slicer' software on the computer as an intermediate step between the STL export from whatever CAD software your using before actually sending (specific instructions for your model) to the printer.

So, if you wanted to print directly from an iPad, my guess is that you'd need a model of printer that 'slices' STL itself, without desktop software. Even then, you'd probably need (a Lightning <-> USB adapter and) a USB drive to actually get the file from iPad to printer.

I haven’t played with 3d printers in a while, but my understanding is that they’ve pretty much standardized on the STL file format to describe prints. CAD packages should be able to export it, and printer software can read it.

Other than that, there’s likely a bunch of parameters that control the actual printing process— there are a lot of tradeoffs to make between print speed, material usage, part strength, etc. The printer software will ask you about these before starting a print.

https://en.m.wikipedia.org/wiki/STL_(file_format)

> I haven’t played with 3d printers in a while, but my understanding is that they’ve pretty much standardized on the STL file format to describe prints.

Not quite. The STL is the model. A slicer “slices” the model into tens to thousands of layers and creates a GCode file that tells the printer exactly what to do.

Generally speaking, the CAD software will output an STL file (surface geometry), then you import that into "slicing" software that takes the geometry and generates .gcode that is targeted specifically for your 3D printer.

I made a video about it here.

https://www.youtube.com/watch?v=PDeCltdVU3w&t=1s

As others have said you export an STL file from your design software. This goes into a slicer (Slic3r, Cura, etc.) If you set up your printer with OctoPrint running on a Rasberry Pi you could do the slicing there, but you quickly run into the limitations of auto-slicing.

It depends.

I personally use Inventor, and there's a nice easy way to convert to STL's in the application.

You then take your slicer of choice (Cura is popular) and toss the STL in there, and click print.

Pretty close to plug & play.

This is what I use as well, plus repetier printing server on my old raspi B.

I've setup everything once about 2 years ago, and should probably update the toolchain (klipper is awesome).

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