3D printing complex shapes or hollow parts can sometimes be problematic. What if you could print them flat and fold the part to the desired configuration? This requires a combination of the right material, design and print strategy. When done properly, the results are highly useful.
The Right Material for 3D Printing Living Hinges
Fortunately, FilaOne™ GRAY is an ideal material for such applications. It’s combination of high mechanical strength and resilience make it the ideal material for 3D printing living hinges. This material will not crack when bent, and these printed hinges will not wear out, even after constant flexing.
The photos below show a printed part with 6 sides segmented by hinges made with FilaOne™ GRAY.
The Right Design
This cube shaped box is assembled by folding each segment and press fitting the tabs into the adjacent side wall. By designing in V shaped notches between sections the walls fold neatly with minimum stress. The thin hinge bends and holds in place.
Interested in DFP? Read our article: design for 3D printability.
The hinged connecting tabs have been designed to fit snugly into the corresponding female notches. Press fit the hinged tabs into the notches and there is sufficient pressure to keep the tabs in place, even when under mechanical loading.
The hinges were designed to be two solid layers thick, providing for a balance of flexibility and strength. This design utilizes the characteristics of the material to create a stable and mechanically strong box.
The Right Print Strategy
3D Print strategy provides for mechanical strength where needed and flexibility where appropriate. In this example, the part was printed with a single outer layer and 25% infill. This implements the appropriate balance of strength and flexibility: the walls are stiff but the hinges flex sufficiently to allow for stable 90º bends. The two layer tab hinges provide the flexibility to press fit the tabs in place without sacrificing strength.
Make Complex Working Parts that Flex
Proper use of hinges greatly expands your ability to make useful, complex parts that will hold up under use. If you would like to receive the .STL file for this hinged box, write us at: firstname.lastname@example.org.
While flexible when printed in thin profiles, FilaOne GRAY can deliver very stiff and strong parts when designed properly.
We will cover this in future blogs. To get an idea on the versatility of this “high strength to weight ratio” engineering grade filament, check out our torture test video below: