Printopia: Tangrams to Learn About 3D Printing

A 3D Printer was added to the Roosevelt Island branch of the New York Public Library's resources last year; it is currently only brought out with intended programming. Our project aims to explore a method to integrate the 3D Printer into the Teen Space to prompt patrons to learn this digital fabrication tool, leveraging its potential to enhance existing paper crafting activities like 'Carts and Crafts.’

To solve this challenge, we decided to make a set of Tangrams that the teens can play with. How does this help them learn about 3D printing? Each tangram set explores different printer settings: infill density and infill patterns that can help the teens make these considerations when they print their custom designs at the library.

Supplies

PLA Filament
Designs:
Tangram pieces [here's the one we used]
Tangram case [tangram-case.stl]
Chest for drawers [tangram-drawer-v1.stl]

Step 1: Design Chest of Drawers

Follow these instructions to design the chest of drawers in Fusion 360:

Create a sketch on any plane. Make a 2D rectangle with dimensions 56x140 mm.
Extrude it with a distance of 10 mm.
On the extruded surface, create a new sketch and make two 2D rectangles of dimensions 13x120 mm.
Extrude the new surface with a distance of 120 mm. Make sure to join it with the previous body!
Lastly, add a fillet of 2mm to all edges.

Note: Make sure to extrude before adding the slots to place the tangrams. This ensures that the back is secure and the tangram sets don't just fall out the other end.

Step 2: Time to Print!

First, we'll print the Tangram cases and chest of drawers. Adjust the printer settings according to your printer; here's what we recommend:

Infill density: 15%

Infill pattern: Grid

Print without supports and a filament color of your choice!

Step 3: More Information on the Tangram Sets

The idea is that infill density is like filling a cake with frosting. Higher density means more solid, like a cake with lots of frosting. Lower density? Airy, like a cake with less frosting. If you try our tangram, you’ll see that the pieces printed at 95% infill density feel heavier, like a solid rock. 10% is lighter, like a fluffy cloud. Heavy pieces are sturdy and great for strong structures. Light ones are easy to carry around! The infill density influences the strength and weight of your 3D prints and the printing time. Higher infill densities, like 95% and 75%, require more material and time to print because they fill more of the interior space, like frosting a cake thickly. These densities produce denser, more solid objects but take longer to print. Similarly, lower infill densities, such as 10% and 15%, use less material and print faster since they have more hollow space, like lightly frosting a cake. While they may be lighter and more flexible, they can't bear as much weight and may not be as durable.

Now imagine the frosting on the cake could be laid out in different patterns! That's where infill patterns come in. Like decorating a cake with different designs, infill patterns affect how strong, flexible, or light your 3D-printed object will be. For example, a honeycomb pattern is strong but lighter, like a bee's hive. A grid pattern is sturdy, like a brick wall. Explore our tangram: notice how each piece feels different in weight, strength, and flexibility.

Let’s take a look at some of the infill patterns:

A concentric pattern provides uniform support and strength from the center outward. It's suitable for objects that require even strength distribution and can help reduce print time by minimizing unnecessary infill. This would be great for customized jewelry stands or earring holders.
The grid pattern is sturdy, like a brick wall. It provides good structural support and is suitable for objects that require stability and durability. However, it may increase print time due to its dense structure. This could be great for smartphone or tablet stands for gaming or video watching.
A honeycomb pattern is like the best of both worlds — strong and lightweight, resembling a bee's hive. It offers an excellent strength-to-weight ratio and efficiently reduces material usage and print time. This could be great for customized keychains or key holders.
A lightning pattern can be used for a dynamic pattern; it can be used for patterns. But be careful; it might not always work.
A Hilbert curve pattern can be used for intricately designed puzzle boxes.
An archimedean chord pattern can be used for a spiral-like pattern

We hope that this project gives the teens and even the library staff insight into infill density and patterns and that the examples encourage them to consider these settings while printing their designs at NYPL!