3D Printing for Games – Part 3

Digital Model to Physical Print Overview

Part 1 of this series provides some of the basics to consider when choosing a 3D printer, while Part 2 gave you a quick contrast of FDM and resin printers, the most common consumer-level printers available. In this entry I’m going to talk in general terms about the end-to-end process of creating a 3D print, and that’ll lead to more specific topics for future posts.

Here’s the 30,000 foot view of producing a 3D print:

  1. Obtain a digital 3D model file.
  2. Convert your 3D model file to a gcode file using a slicer application.
  3. Feed the gcode file to your printer. (Subtask: wait.)
  4. Finishing work.

That’s it! Pretty much three steps, since often there isn’t any finishing work. Let’s explore each one.

Obtain a Digital 3D Model File

Can of worms, right away! There are quite a few ways to obtain your 3D model file, but let’s start with the easiest:

Get a file from a website: yep, it’s that easy. Visit Thingiverse.com, one of the best places online to look for 3D model files. You’ll find tens of thousands of 3D models, free for personal use. Just try searching for “Pokemon” there. To see all the search results you’ll be scrolling until the cows come home, and the cows are evidently on an extended vacation.

One of the best things about Thingiverse is that many of the designers go into great detail about the best settings to print their designs. You’ll also see comments and questions from other folks who’ve printed the models; they might have more suggestions for the best way to print a given file. While you’re at Thingiverse feel free to visit my profile and you can see a few designs I’ve uploaded.

There are plenty of other websites where one can obtain 3D models, including some that require payment. Lately I’ve been backing 3D model sets on Kickstarter as well. However, there are more than enough models available for free to keep a budding 3D printer enthusiast busy for a long time.

Make your own: it’s not that difficult. In fact, if you visit Tinkercad.com, you can start creating your own models in no time using a browser-based, drag-and-drop interface. It’s free and it’s very easy to use. Schools and Maker spaces all over the world use Tinkercad to introduce kids to 3D printing, and it’s a great way to learn the basics that you can take to other applications.

As you may have guessed from the name “Tinkercad,” 3D models are typically constructed in CAD programs. Some of the best known out there include Sketchup, Fusion 360, AutoCAD, Blender, and Sculptris. Many are free, or offer limited, free versions to try out.

Learning curves vary quite a bit on CAD programs. Some are oriented toward engineering design, while others focus more on organic or artistic approaches. For example, Blender is a modeling application which includes animation and physics features — it’s actually used for 3D animation in movies and video games, as well as non-animated models for 3D printing.

My CAD of choice is OpenSCAD. It’s quite a bit different from all the others I’ve mentioned. (Aside from the fact that like many of the others, it’s free.) With most CAD programs you directly manipulate the model, almost as if you’re sculpting. OpenSCAD is a programming language; you write code which is then translated into a visual model. It’s a great choice for someone like me — someone who enjoys programming, but still makes a lowercase “m” when asked to draw a bird.

Scan something: to the non-geek this may seem like science fiction, but you can indeed scan an object (or person) to create a 3D model. If you’re just embarking on 3D printing, I don’t recommend starting with 3D scanning.

Among other things, you’ll need additional equipment and software, chiefly, a 3D scanner. I actually use a Kinect sensor for a scanner, along with programs such as Skinect and ReconstructMe to make scans of people. It’s fun, but this isn’t really beginner territory.

Convert to gcode with a slicer

Okay, you’ve got a 3D model file. Next, you’ll need a slicing program. The slicing program prepares your 3D model for printing, translating it into instructions (called “gcode”) that your printer understands. The slicing program does some other critical things, too, such as adding support material for your models. (I’m going to explain support in another post; it’s a topic worthy of its own entry.)

The gcode file is a long list of instructions to your printer:

  1. Heat the extruder to 185F.
  2. Heat the bed to 60F.
  3. Move the extruder to the 0,0,0 position.
  4. Move the extruder to 45,120,0.
  5. Begin laying down plastic.
  6. Move to…you get the picture.

Good news: you probably don’t have to worry about getting slicing software. Most 3D printers come with slicing software specific to that manufacturer. For instance, FlashForge printers come with FlashPrint.

The manufacturer’s slicer is just fine for getting you started, and some people use nothing but the manufacturer’s slicer. However, other slicing applications, both free and purchased, bring more features and sometimes greater control of your printer.

CURA, Slic3r and OctoPrint are three of the most popular free slicing programs. They’re all quite powerful, and OctoPrint has a lot of really cool plugins. For example, you can use OctoPrint in conjunction with a webcam to make really cool time lapse videos of your printer in action. Again, though, the slicer that came with your printer is just fine for getting underway.

Feed the gcode to the Printer

Incidentally, I skipped a sub-step in here. You should level the printer before printing. Every time. Whether you have to manually level or you have an auto level feature, do the leveling process before every print. There’s nothing more frustrating than being two (or ten) hours into a print and having it detach from the bed. Game over, everybody out of the pool.

But really, once you have your gcode file, you’re good to go. Send it to the printer, and watch the magic happen. Then go watch a movie while the magic continues happening.

How you send the gcode file to the printer depends a great deal on the printer you purchased. As I mentioned in Part 1, my printer accepts an SD card, and I’ll always heartily endorse this feature. Most printers read the gcode one line at a time; they don’t load and buffer the entire file.

That means that if you’re feeding the gcode to the printer by connecting your laptop via USB, your laptop must stay connected the entire time you’re printing. That’s not necessarily a bad thing. The printers at our MakerSpot are tethered to laptops and the slicing programs can be used to monitor and interact with the print. For instance, the user can pause the print, switch to a different color filament, then resume printing.

Finishing Work

You may want to do some painting after your print is done, or use sand paper, scissors, and a Xacto knife to clean up rough areas. There are other types of finishing work as well, such as acetone polishing Let’s not go down that path if you’re new to printing, however. That’s definitely in the advanced category…

Have You Followed Four Day Weekend Yet?

If you’re finding this blog series valuable, please feel free to share it. And definitely check out the Four Day Weekend walkthrough, then sign up for the Kickstarter launch notification.

Until next time…


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