3D printing is a really cool way to quickly build models. The are many different types of 3D printing, but the simplest involves printing layer by layer. In a past blog post we explored 3D printing ideas using modeling clay (Part 1 and Part 2). Another way to think of this is to imagine squeezing some hot glue onto a piece of paper. Then once that layer dries, you squeeze more hot glue on top. If you do this over and over eventually you will end up with a tall 3D pile of glue (though it may not be very pretty...)!
One type of 3D printer works just like this, called a "fused deposition" printer. Except that instead of hot glue sticks it uses plastic strands, and instead of your hand and arm controlling where to put the plastic it uses motors.
In order to print something, you need a computer file to tell these motors where to move and when to print. We talked about 3D design in a previous blog post (3D design in Tinkercad). For this design, we built Sparky. Here is a link to the 3D printing files (or you can find them on Thingiverse). These files can be printed on most 3D printers.
If you would like to print this model yourself, try asking your local library, school, or science museum if they have a 3D printer you can use. If you can't find a printer, 3D Hubs is a neat company that will help you find local businesses to do your 3D printing - though it's certainly more interesting to see the 3D printer in-person! Here is a movie of Sparky's body being 3D printed.
Look closely and you'll see that this is being printed with something called "supports". We talked about this in our previous blog post (3D Printing with Modeling Clay Part 2). Imagine trying to squeeze some hot glue 10 cm above your table - it would fall! So if anything in your part is sticking out you need to hold it up with thin plastic supports. Then when the print is finished, you break away the supports. Here is the part before and after removing the supports.
Each of the joints is printed in place. When they first come off of the printer they will be a bit stiff, but they can be moved by wiggling them around until the supports inside of the joints break apart. We repeated this process for each of Sparky's body parts.
Next, the pieces were connected together by pressing the pegs into the holes at each of the connections.
Then all that was left to do was paint! We went with the classic blue and red, but maybe next time we'll try some different colours and patterns!
If you have any questions please ask us in the comments below. And if you 3D print Sparky, we'd love to see your creation! If you are interested in making your own 3D design files, check out our blog post on 3D Design with Tinkercad. Thingiverse is another cool website where you can download 3D files that other people have made. Happy printing!
This activity is based on the book If: Ball, Then: Catch, available here!