Saturday Science: 3-D Printing Power
The wild and wonderful world of science fiction is full of inventions and technology that probably can’t exist anywhere outside of the imagination: faster-than-light travel, laser swords, and teleportation come to mind. But sometimes tech from sci-fi makes the jump to the real world. Sometimes engineers in the real world even look to science fiction for inspiration! For example, old-style flip phones were designed to open and close specifically because Captain Kirk’s communicator on Star Trek opened and closed. The first submarine was invented by someone inspired by the Nautilus submarine from the classic sci-fi novel 20,000 Leagues Under the Sea by Jules Verne.
Well, today we’re going to talk about some less common, more cutting edge technology that has a lot in common with something from sci-fi. Going back to Star Trek, their version of the 24th century (starting with Star Trek: The Next Generation) has machines called replicators. Replicators take matter, break it down into energy, and reassemble it into anything you might want: food, drinks, clothes, tools, even a guitar in one episode.
Now, that kind of technology is way beyond us, and it may not even be possible, but we do have something similar today: 3D printers. 3D printers can’t make anything out of anything, but they can be very useful for making specific objects out of specific materials. Today we’re going to model how most 3D printers build objects by becoming a 3D printer.
- A hot glue gun
- Lots of hot glue sticks
- An adult (This is important! Hot glue guns are called HOT glue guns for a reason!)
- Wax paper
- A baking sheet or some other tray-like object that isn’t made of plastic
- Paper and pencil
- Templates (optional)
- Plug in your hot glue gun and set it on your tray-like object while it’s heating up.
- Make sure there is an adult around! I’m serious about this!
- While you’re waiting, decide what you want to make. If you want a guide, print out the templates you can download above for a star, heart, and square shape. If you want to be creative, draw an outline (maybe a person, or a dinosaur, or something else cool) on your paper, and make it dark and thick enough to see through wax paper. Make sure it’s just an outline, though. That’s all you’ll need.
- When your glue gun is ready to go (some glue is dripping out of the tip), lay your design on top of your tray-like object and cover it with a sheet of wax paper.
- Pick up your glue gun and position it above one part of the outline of your design. Squeeze the trigger with gentle pressure and as the glue flows out, use it to trace your outline.
- Once your outline is finished, begin to fill it in. Many 3D printers fill in space using a pattern of diagonal lines crisscrossing inside whatever’s being printed. It’ll make the inside strong without needing to 100% fill it in.
- Once you’re done with your diagonal fill-in, wait a minute or two for the first layer to cool down a bit, then put another layer of outline glue on your shape, then fill it in again.
- Rinse and repeat these steps until your shape is as tall as you want it to be.
- Gently peel your completed object off of the wax paper. If it’s getting sticky, you can try heating a pot of water on the stove, then holding the wax paper above the water to melt the wax a bit and let your object slide off.
- Voila! You have 3D printed a basic shape!
Real 3D printers (at least the most common kind that regular people can buy) build stuff using a process called “extrusion printing.” “Extrude” basically means to squeeze something out through a small hole. When you squeeze ketchup out of the bottle, it is being extruded. Likewise with 3D printers. A thin plastic string (the “filament”) is fed into the top of the printer, down to a cone-shaped part called the “extrusion tip,” and it gets melted and squeezed out as a much thinner plastic string. As the plastic is being extruded, the tip moves around above the printer’s base, tracing a shape from the bottom up, building it layer by layer.
Sound familiar? The cone-shaped tip of a hot glue gun is just a less fancy version of the extrusion tip from a 3D printer. It heats up a stick of glue and squeezes it out smaller than it went in. As you build up layers, you were doing exactly what an extrusion printing 3D printer does, just on a bigger scale!
Now, real 3D printers can print really complex objects, as compared to your pretty basic shapes. This is because they work from 3D computer models of objects, and they’re able to leave empty spaces where they’re needed and change each layer to build up an elephant or a wrench or a teacup or even all the pieces you need to build a fully functioning prosthetic hand. And there are 3D printers that don’t use plastic to build with. Some use metal, some can use food, there are huge ones that can use concrete to 3D print walls and entire structures, and medical scientists have even made ones that can print using living cells! We may be entering and era soon when people can have new organs 3D printed from their own cells for an organ transplant, and that is insanely cool. They can’t make anything out of anything, like a Star Trek replicator, but they’re the closest thing we have and they’re incredibly useful in all kinds of industries.
And at home, if you like to play Dungeons and Dragons and don’t want to buy a bunch of expensive miniatures. But maybe that’s just me.