Using Your 3D Printer with SketchUp - dummies

Using Your 3D Printer with SketchUp

By Aidan Chopra, Rebecca Huehls

SketchUp and 3D printers are a match made in heaven. Your new 3D printer’s manufacturer will have documentation to help you learn how to use the printer and the software. The following information touches on a few general concepts of 3D printing that are often not explained well. For a closer look at 3D printers, check out 3D Printing For Dummies by Kalani Kirk Hausman and Richard Horne.

Print early, print often with SketchUp

Desktop 3D printing is cheap. Really, unbelievably, remarkably cheap. Cost for running a typical desktop 3D printer is about 60 cents an hour. Once you’ve started the printer, it doesn’t need any more input from you, which frees you to continue working on the design. With such an amazing tool that’s so cheap to use, don’t be afraid to print constantly. Print your SketchUp model over and over as you improve it; doing so develops it.

3D printers are built to print; they don’t like to stand idle. Print more often! You’ll become an old hand at using your machine, and get to see your design as it evolves in real time.

Test prints are great for catching errors and mistakes. Test prints are also a great way to document the evolution of a design. It’s a good idea to save a version of your SketchUp model that corresponds to each file you 3D print. If the print has an unexpected error, you can look back at that file and understand what went wrong, without having to dig too deeply into the version you have continued to work on. Keep some general points in mind:

  • Test prints that use your 3D printer’s Low Quality setting will print faster, but with a rougher surface.
  • Save test prints as the project goes on. They’re a great way to show progress, and clients love to see a physical expression of the work being done.
  • Many 3D printing plastics are recyclable or biodegradable. When you’re done with your models made of this stuff, toss them in the recycling bin or on the compost heap.

Inside your SketchUp model

3D printed parts are unique in the world of fabrication. After you’ve created the outside of your part, you also get to decide what happens on its inside. Usually you let the 3D printer automatically handle the inside of the part, filling it with automatically generated structure. It’s also possible to model a part’s interior structure to change how it behaves. For example, you might want to hollow out the center of a part to make it lighter or add space for internal components. Some possible variations include

  • Internal voids: On SLS and stereolithography machines, a common cost-saving strategy is to build parts as a thin shell with an empty interior. The resulting parts have compromised structural strength, but are printed using as little material as possible. Be sure to include drain holes so the un-hardened material you saved can escape from the part.
  • Part density: FDM printers automatically generate a structure to fill the interior of their prints. The density of the structure is controlled by a setting called fill, which is stated as a percentage. Parts with 100% fill will be solid plastic all the way through, and are as strong as injection-molded parts. Typically, FDM printers default to building parts at 10% fill, meaning that 10 percent of the interior is filled with plastic. Higher fill percentage means more plastic used — and longer print times. Generally speaking, anything over 40 percent is a waste of time and plastic.
  • Outer wall thickness: Another FDM printer setting, this deals with the amount of material put into the walls of the object before starting the Infill. Look for a setting called Shells, which is the number of layers of plastic the printer will use to make the outside of the model. If you’re having trouble with parts crushing, increase the number of Shells; otherwise leave this setting alone.
  • Flexibility: Flexible materials are available on most 3D printers, usually by using a special flexible plastic filament. You can also make structures flexible by making them very thin with 0 percent infill.