(Get it? Because of Harry Potter?)
“ If you wish to make apple pie from scratch, you must first invent the universe.Carl Sagan
If you wish to make apple pie from scratch, you must first invent the universe.Carl Sagan
Ah, Sagan. What a quotable m-f-er.
If you wish to 3D print, you must first have something to print. That is accomplished by making or obtaining a 3D model.
Now, getting your hands on a 3D model can seem like a pretty big order to fill if you’re new to the game. It’s like if, in order to get your driver’s license, you also had to learn how to build all the parts of the car.
That’s the thing with 3D modeling: not everyone will want or have time to make all their own models from scratch. And that’s 100% fine. Some people will want to buy a copy of an existing model in the material of their choice; some people will want to start with existing models, and then level up to making their own. Others might want to modify or customize someone else’s basic model to fit their specifications. All of these are perfectly acceptable ways to get started with 3D modeling and printing.
Today, we’re going to dive into the latter category, because sometimes you just want to get to the eating part of apple pie, and not mess with all that universe invention stuff.
What is a 3D model?
At its core, a 3D model is a mathematical representation of a three-dimensional surface. There are many, many different types of 3D models, but for our specific purposes, it means that the objects we’re making for 3D printing- whether they’re straight, curvy, spherical, whatever- are broken down into a series of polygons to form a mesh of the surface that can be easily processed and rendered by a computer.
Take, for example, this 3D model of a rosemary sprig pendant I designed:
This piece is just under 3” long, and from a wide view, the surfaces look quite smooth and organic. But when we zoom in, we see this:
The surface is actually composed of an s-load of tiny triangles and polygons- like pixels of a photo. Then, when the model is being processed for printing, the software essentially cuts the model into a bazillion tiny slices. Then, as we discussed in “What is 3D printing?,” the the printer takes this information and builds the model with these layers in the material of your choice. Depending on the design, material, process, etc, these layers can be quite noticeable, or almost invisible.
Here’s the same model, but now Meshmixer is analyzing how it will be sliced. It’s exactly like a topographic map.
So, why you would want to use an existing model?
There are a number of reasons to start your 3D printing journey with a ready-made model. First, 3D modeling is a skill like any other- it does require a bit of practice. It’s not a bad idea to take a gander and see what other people are making and building when you’re first starting out. It’s especially helpful if you’re able to download a full Fusion 360 model- one that still shows the timeline/workflow. Poking around other people’s models will teach you so, so much.
Sometimes, too, a ready-made model can be very helpful if you want to customize the aesthetics of an object- say, an iPhone case- but don’t want to start from the ground up.
And lastly, some people just don’t have the desire or time to do their own 3D modeling. That doesn’t mean, however, that they can’t get in on the fun of 3D printing. Whether that means just being able to say, “And it’s 3D printed!” when someone compliments your bracelet, or doing some crafty post-processing like custom dyeing or painting, there’s plenty of ways to be a part of this world.
Where do I find printable models?
One of the cool things about printing platforms like iMaterialise or Shapeways is that they have integrated marketplaces where you can buy the designs of a huge number of artists (cough cough, including those of your’s truly, cough cough). It’s basically Etsy for 3D printing. Find something you like, then have it printed in the material of your choice, just for you. A few days or weeks later, it’s on your doorstep. Here in the present, but made in the future.
Thingiverse is a website (owned by 3D printer manufacturer MakerBot) full of open source designs- from drone parts to kitchen accessories to jewelry and wearables. You can download the files and make them yourself- lots of the designs are for 3D printing, but you’ll also find files intended for laser cutting and CNC.
Like any open source resources, what you’ll find will be a mixed bag. Anyone can upload anything, so there will be incomplete models, untested models, and impossible-to-make models scattered amongst the good ones.
When you’re first starting out, look for models that have a proven track record- i.e., positive comments from other people who have tried to use them, photographs of actual builds, etc. It’s not too different from online shopping or trying to find a decent dentist that takes your health insurance- look for the good reviews, and use common sense if something seems to be too good to be true.
Coming soon, I’ll be showing you how to take a model downloaded from Thingiverse and make your own customized version in Fusion 360. Get excited.