Simple STEAM Project: 3D Printed Keychain

Are you looking for a fun project to introduce students to 3D printing and modeling?

I have done this activity in our makerspace with middleschoolers and with college kids. It is a simple way for learners of all ages to get started with TinkerCAD and using the MakerBot 3D Printers!

Supplies

Equipment: Makerbot PLA Printer or other 3D Printer

Materials: PLA Filament, keychain rings (optional)

Step 1: Getting Started With TinkerCAD

Option 1: Individuals each create an account

Visit https://www.tinkercad.com/ and log-in (I recommend using a Google Account for log-in)
Select "Create a New Design"

Option 2: Instructor provides access via a Class

Ahead of time, the instructor creates a TinkerCAD class: https://www.tinkercad.com/dashboard?type=classes
Once the class has been created, click on its name to view and add students
Add students by providing a name and a nickname (these can be generic, such as Student01, or specific to your roster.
Provide the class link and the nickname to your students to use for log-in
Benefits of this option:
no email access needed for students to sign in
instructor can easily view all designs created by the students
if desired, the instructor can create a base design for the students to Tinker

Step 2: Modeling the KeyChain

From the right drop-down menu, choose "Design Starters"
Then, choose the sub-category "Letters and Numbers"
Click and hold on a block letter and drag it onto the workspace
Change the view to Top View by clicking on the cube to the left of the workspace
Optional: I like to change the view to Flat View to turn off any perspective
Select a new block letter and drag it to overlap with the first Block Letter
Note: The more the letters overlap, the stronger the bond will be. Change the Snap Grid values (at the bottom right of workspace) and nudge the letter up/down or left/right using the arrow keys to get it in the right place.
Repeat until name is complete

Step 3: (optional) Fun Shapes

From the right drop-down menu, choose "Basic Shapes" or "Characters" or "Shape Library"
Browse shapes and select something to add to the keychain
Drag it into the workspace, resize, rotate and place on your keychain
- Note: since you will need to resize most shapes and rotate characters, I recommend this option for someone who is already comfortable with TinkerCAD or for more advanced students.

Step 4: (optional) Adjusting the Letter Height

The block letters are the perfect size to make small keychains. So there is no need to resize the letters. If you wish to create a sense of dimension, you can edit the height of the letters by following these steps:

Click on the cube to the left to change the perspective to the Top/Front view
Click on a letter and then on the white cube in the center
Type a "3" in place of the "4"
Repeat other letters you wish to alter

Step 5: Adding the Keychain Ring

Use an "O" for the Keychain Ring.

Drag an "O" into the proper location.
Change the pespective to be able to easily view the "O"
Clicl on the letter, and then subsequently on the white sizing cubes. Change the dimensions by clicking on and retyping the numbers.
Resize it to "3" x "3" in width and length; and "2" in height.
- Note: The default dimensions for TinkerCAD are mm. So we are making a 3mm x 3mm circle with a hole that is approximately 1mm in diameter.

Step 6: Export STL File

Type "Ctl + A" or drag and click with the mouse to select all the shapes in your workspace
Type "Ctl + G" or click on the Group icon to group all the shapes into a single one
- Note: The color will change; colors do not export with STL files
Click on the "Export" button
Choose to export an "STL" for 3D Print

Step 7: Prepare File for 3D Printing

Do this step for your students, or guide them through the process themselves!

If you have a Makerbot printer, visit https://cloudprint.makerbot.com/ to prepare your print.
Note: use another program for other 3D printers
Log in at the prompt (I recommend using the Google Log-In)
Click "Print Preparation" at the top right corner
Click on "Add Models", then choose "Add File"
Browse for the STL file you exported from TinkerCAD

Step 8: 3D Print Settings

Select the Makerbot printer
Select the correct extruder
Select the desired base layer:
Base layers are required for printers without heated beds:
The default "Raft" will create a smoothe bottom surface
"Padded Base" will print quicker and will waste less plastic, but will have a base layer with thicker extrusion lines.
Printers with heated beds to not require any base layer
Change the number of shells to 4 for a stronger key chain ring
Change the infill to 0.2 for a stronger key chain in general
Select "Export" and save the file to a USB drive