Here is a very handy approach to planning for overhangs and other support-risks with a figure — check it out!
Supports vary in different 3D print preparation software and it’s an area that clearly is still not perfect, especially for the more creative prints like the one I’ve presented her. And of course supports need to be removed. If the supports are hard to get to because they’re inside the piece where they can’t be easily reached or deep in a recess it’s possible surgical cleanup efforts will be necessary before you can use your 3D printed part. And FDM supports have other weaknesses. Rounded bottoms don’t come off quite round enough. Fine details may break off with the supports. And leavings of the supports may still be there, even after cleanup. There are, of course, other techniques for fixing this. Like rotating the print to carefully position the parts that need support, or cutting the print into parts and assembling them afterwards. These techniques can work, but still require an expense of effort in cleanup.
That’s why most of the things I design will print entirely without supports. The pose I did choose when modeling the wizard might not have been as interesting, but it does print without supports. Designing this way requires a little extra effort but insures that objects will come off the build platform ready to use without any cleanup. To design for support-less printing requires knowing a few little rules. Those rules be easily remembered with the letters “YHT”.
The letter Y standing on a build platform slopes out gently. Even though the layers are getting bigger they’ve got enough of the previous layer to stick to that they won’t droop or fall. This sort of gentle overhang is perfectly safe and will result in successful prints. Generally speaking 45 degrees or less is perfectly safe. More than 45 degrees can work in certain circumstances, I’ve had overhangs of up to 70 degrees work successfully, but don’t make it a habit without some experience.
The letter H standing on a build platform has 2 towers that “bridge” in the middle, and this bridging is actually relatively safe as well. It’s not 100% sure, but if a layer has a place to start and a place to end then it will bridge an open air gap successfully. It’s not as safe as the “Y” example was, but it’s still pretty safe.
The letter T, on the other hand, is right out. (Doubly so if it’s serif.) Danging out into open air with nothing to latch on to will result is sloppy, messy, failed prints. Avoid this sort of thing if you want your print to work without supports.
These rules are, of course, completely academic. If you actually wanted to print a letter you could just lay it down on the build plate. But these letters will help you make successful prints that won’t need supports, or will only rely on minimal supports, when printing.
And of course none of this matters if you’re using a tens of thousands of dollars professional 3D printer. Do whatever you want when you use one of those. You’re paying enough for it.
Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!
Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!
The Adafruit Learning System has dozens of great tools to get you well on your way to creating incredible works of engineering, interactive art, and design with your 3D printer! We also offer the LulzBot TAZ – Open source 3D Printer and the Printrbot Simple Metal 3D Printer in our store. If you’ve made a cool project that combines 3D printing and electronics, be sure to let us know, and we’ll feature it here!