Introduction: Build a Personal Locking Container

The following information is a single lesson in a larger project hosted on Tinkercad. Check out more projects like this on Tinkercad

Project description

Make your own 3D printed Lockable Container! In this lesson plan, you will 3D model (and eventually 3D print) your very own locking bank or note jar.Tinkercad is an amazing and free tool powerful enough to create 3D digital files you can use in the classroom, at home and in your work. When you are done, these 3D printable parts will delight the maker in you!

The project includes 3 lessons each about 45 minutes. Previous completion of “Let’s Learn Tinkercad” is recommended. Log in, have fun, and get ready to learn!

Step 1: Model Your Locking Container Lid

Let’s start by creating the top lid of the bank container.

Let’s get started!


  1. Place a cylinder on the workplane and make it 80x80x3mm.
  2. Continue to next step.

Step 2: Add the Locking Tab

In order for your bank to stay locked if it happens to tip over, let’s add in a tab that will fit a lock.

We will be using the “Extrusion” shape in this lesson, which has cool options that allow you to change its shape dynamically through the Inspector window.

Note: It is important to remember, the Inspector window will be presented anytime a shape is selected in Tinkercad. This will allow you to change the properties of the shape generator at any time even after initial placement.

When you click on the extrusion object you see a circle in the inspector window with circular handles and square control points. Move those boxes are around and you will see the shape update immediately.

The squares control the overall shape of the object, and the circular points control the slope and angle of the edges. Move the points and handles around until the shape looks roughly like a boomerang.

Move the boomerang shape onto the right side of you container lid, intersecting it completely, and match the lid height, at 3mm.


  1. Expand the Shape Generators panel in the browser on the right of the screen, then expand the Tinkercad panel and locate the Extrusion shape.

    Note: The Extrusion shape will show as a gray cylinder in the panel, but we will change its shape.
  2. Drag an extrusion shape from the Tinkercad panel, place it on the workplane, and use the inspector window to drag points on the circle and change the shape of the extrusion to look like a boomerang.
  3. Reduce the height of the extrusion to 3mm tall, so it matches the thickness of the lid.

  4. Move the boomerang shape to make it intersect with the lid shape.

  5. Continue to next step.

Step 3: Make Some Threads

There are many ways to have the lid fit inside of the body of the container. One good way to attach the lid to the container is by using threads to twist the parts together.

A threaded lid has the advantage of only needing a lock on one side, and the threads themselves act as a lock as long as they are twisted together and are fully engaged. If we didn’t have threads, we would need two locks on each sides to keep the container lid secure on both sides.


  1. Expand the Shape Generators panel in the browser on the right of the screen, then expand the community panel and locate the Twisted Polygon 4 shape.

    Note: The Twisted Polygon 4 shape will show as a yellow twisted cylinder in the panel
  2. Drag a Twisted Polygon 4 shape from the Community panel, place it on the workplane, and increase the height from the default 20mm to 23mm.

    Note: This height change should be made with the settings in the Inspector window. Changes to shape generators made outside of the Inspector window will not be reflected in the Inspector window and may become confusing.
  3. Continue to next step.

Step 4: Align the Threads to the Lid

You want to make sure that the polygon is in the exact enter of the lid so that the threads line up, so let’s use the Align tool.

The Align tool will be used to align the Polygon with the center of the lid. You will know the alignment is complete if the alignment dot turns grey and the word “Aligned” will appears when your mouse hovers over the dots. Remember: The Align tool (along with other tools like the Group tool) require multiple objects to be selected.


  1. Hold down the Shift key on the keyboard and click the Twisted Polygon and the lid to select both at the same time.

    Note: Make sure you do not select the boomerang shape. If all 3 shapes are selected the align action will not align the centers of the cylinder shapes.
  2. From the Adjust menu, select the Align tool.
  3. Click the black alignment dots that will center the Twisted Polygon to the lid.

    Note: The image above show which alignment dots to select. One is shown in red and the other is shown as grey.
  4. Continue to next step.

Step 5: Configure the Threads

This next part is more technical than creative, but it is incredibly important. If the threading on the lid and container aren’t set to specific sizes, then the threads won’t line up and you won’t be able to close your container!

You are making the “inner threads” now and you will model the “outer threads” later in this project.

Tip: Most “numbers” you see in tools like the Inspector can be clicked on and the number entered directly by typing in the number and pressing the Enter key.Try that in this lesson!


  1. Click on the Twisted Polygon to select it and enter the following values in the Inspector window.
  2. # of Points: 8
  3. Radius: 35mm
  4. Height: 20mm
  5. Bottom Twist: 10 degrees
  6. Top Twist: -10 degrees (negative ten degrees)
  7. Continue to next step.

Step 6: Set the Lid Aside

You have now completed the lid of the container. We can set the lid aside on the workplane, just like you might if you were building this on your desk.

Move the lid off to the side of the workplane so we have room to begin creating the base of the container.


  1. Drag a box around all the shapes to select everything and drag them to the upper left corner of your workplane so they are out of the way.
  2. Continue to the next step.

Step 7: Preparing to Create the Container Body

When you create designs that need to work with other designs, it is good practice to reuse what you have already built to make sure everything lines up and to save time.

In preparation for making the container body, we need to re-use some of the old pieces as components for the new one. A great example of this is the threads: they need to match perfectly in order to work!

Since you want the body of the container to match the lid, you can re-use the lid pieces to build the body….rather than having to remember and re-create all of the measurements you made earlier.


  1. Drag a box around all the shapes to select everything and then select Duplicate from the Edit menu

    Note: This will create an exact duplicate of all the shape in the exact same position.

  2. With the shapes still selected drag them to the right, so we can use these copies in the next lesson.

  3. Continue to the next lesson.