Learn the TinkerCAD interface, design a working fidget spinner with proper weight distribution, and export it ready for 3D printing, no experience needed!
Get TinkerCAD open with a new blank design ready to build in.
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Parent note: TinkerCAD runs in any browser, nothing to download! Go to tinkercad.com. Click "Join Now" and choose "Personal". For under-13s, a parent creates the account using "Students under 13 join a class."
Get started
1Open a browser and go to tinkercad.com.
2Click "Join Now" in the top right corner. Choose a "Personal" account.
3Once logged in, click "Create" then "3D Design". A new empty workplane opens.
4You'll see a flat blue grid, this is the Workplane where you build.
5On the right side is the Shapes Panel, these are the building blocks for your design.
The TinkerCAD editor. ① Project name (click it to rename) · ② Export button (you'll use this at the end) · ③ ViewCube (click its faces to change view) · ④ Workplane, the blue grid where you build · ⑤ Shapes Panel, drag shapes from here.
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Click the project name at the top left ("Untitled") and rename it to "My Fidget Spinner".
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Fill in the Blanks
+15 XP
TinkerCAD runs in your so there's nothing to .
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Knowledge Check
+15 XP
What is the Workplane in TinkerCAD?
AThe panel where you find shapes
BThe flat grid surface where you place and build your 3D objects
CThe toolbar at the top of the screen
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Explore the Workspace
Learn camera controls, grid, and the shapes panel
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Goal for this step
Be comfortable navigating the 3D view, orbiting, zooming, and panning.
Learn the controls
1Right-click and drag to orbit (rotate) the camera around the workplane.
2Scroll the mouse wheel to zoom in and out.
3Hold Shift + right-click and drag to pan (slide) the view.
4Click the "Home View" cube in the top left to reset the camera.
5Look at the bottom-left: the grid squares are 1mm each. The ruler shows dimensions.
6Try clicking a few shapes in the Shapes Panel on the right, but don't drag them yet!
The three camera moves. Practice each one until it feels natural, you'll use them constantly. On a laptop trackpad: two-finger drag orbits, pinch zooms.
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The small cube in the top-left corner is called the ViewCube. Click its faces to snap to Front, Top, or Side views.
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True or False?
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"Right-click and drag" orbits the camera around your design.
Each grid square on the workplane is 10mm.
The ViewCube lets you snap to different camera angles.
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Knowledge Check
+15 XP
How do you zoom in and out in TinkerCAD?
APress the Z key
BRight-click and drag
CScroll the mouse wheel
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Create the Central Hub
Drag a cylinder onto the workplane as the center hub for the bearing
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Goal for this step
Place a cylinder shape on the workplane. This will be the small central hub where the bearing goes.
Add your first shape
1In the Shapes Panel on the right, find "Cylinder" under Basic Shapes.
2Click and drag the Cylinder onto the workplane. Drop it in the center.
3A cylinder appears on the grid. It has small white square handles for resizing.
4Click the cylinder to select it, you'll see dimension labels showing its size.
5The default size is about 20mm x 20mm x 20mm, we'll resize it in the next step to make it the central hub.
What you should see: an orange cylinder sitting on the grid, about 4 grid squares wide. Don't worry about where exactly it lands, you can move it any time by dragging it.
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If you make a mistake, press Ctrl+Z to undo. You can undo many times!
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Knowledge Check
+15 XP
How do you add a shape to the workplane?
AClick and drag it from the Shapes Panel onto the grid
BDouble-click the workplane
CPress the "Add Shape" button in the menu
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Resize the Spinner Body
Make the cylinder a small flat disc, 30mm x 30mm x 8mm
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Goal for this step
Resize the cylinder to 30mm wide, 30mm deep, and 8mm tall, this is the central hub for the bearing.
Resize the cylinder
1Click the cylinder to select it. You'll see white square handles on the corners and edges.
2Look at the top, there's a small white square handle. Click and drag it downward to make the cylinder shorter.
3In the dimension box that appears, type 8 and press Enter. The height is now 8mm.
4Now grab a corner handle on the base. Hold Shift while dragging to resize both width and depth equally.
5Type 30 in the dimension box. The cylinder is now 30mm x 30mm x 8mm, a small flat disc (the hub)!
6Check your work: select the shape and verify the dimensions show 30 x 30 x 8.
Don't drag by eye, type the numbers. Click a white handle and a small dimension box appears (like the "8" above). Type the exact number and press Enter.
✅Checkpoint: your cylinder should now look like a flat disc, much wider than it is tall, and clicking it should show 30 × 30 × 8 on the labels. If a number is wrong, click that handle and retype it.
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The central body should be small so the arm weights stick out clearly. This creates a spinner that spins smoothly.
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Fill in the Blanks
+15 XP
To make the spinner body (hub) properly sized, we set the height to mm and the width to mm.
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Knowledge Check
+15 XP
Why do we keep the central body small (30mm, not 50mm)?
AIt uses less plastic
BSo the arm weights stick out clearly and the spinner has good balance and momentum
CLarge bodies are harder to hold
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Add Spinner Arms
Add 3 weight cylinders extending outward from the body
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Goal for this step
Place 3 heavy cylinders that extend outward from the center to provide weight and balance for spinning.
Create the first arm weight
1Drag a Cylinder from the Shapes Panel onto the workplane.
2Resize it to 16mm x 16mm x 8mm, this is a weight that will stick OUT from the body.
3Position this cylinder about 20mm away from the center of the body (measured centre to centre).
4Place it at the "12 o'clock" position, directly above the center, extending outward.
5Make sure it sits flat on the workplane at the same level as the body (height 0).
6The arm must overlap the edge of the body slightly (a few mm). When you group everything later, the overlap fuses them into one solid piece, a gap would make your printed spinner fall apart!
Line it up from above. Click "TOP" on the ViewCube so you're looking straight down, it's much easier to position the arm accurately. The arm's edge should clearly cross into the body, no gap and no daylight between them.
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For a spinner to work, the heavy weights need to be far from the center while still overlapping the body. This creates better momentum when spinning.
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Knowledge Check
+15 XP
Why should the arm weights be positioned far from the center?
ASo they don't touch the center bearing
BTo create better momentum and balance when spinning
CTo make the spinner look bigger
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Position Arms Evenly (120° Apart)
Use rotation to space the arms perfectly around the center
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Goal for this step
Duplicate the arm and rotate copies to be evenly spaced at 120-degree intervals.
Duplicate and rotate
1Select the arm cylinder you just created. Press Ctrl+D to Duplicate it.
2A copy appears on top of the original. Don't click anywhere else yet!
3You'll see a rotation handle, curved arrows around the shape. Click and drag to rotate.
4In the rotation box, type 120 and press Enter. The duplicate moves to the "4 o'clock" position.
5With the rotated copy still selected, press Ctrl+D again. TinkerCAD remembers the last action!
6The third arm automatically appears at 240°, the "8 o'clock" position. All three arms are evenly spaced!
What you should see from the top: arm ① is your original, ② appears when you press Ctrl+D and rotate 120°, and ③ appears automatically when you press Ctrl+D again. All three overlap the body's edge, like a clover.
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Parent note: The Ctrl+D repeat trick is one of TinkerCAD's most powerful features. It remembers both the duplication and the rotation, so the second duplicate automatically rotates another 120°.
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True or False?
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Ctrl+D duplicates the selected shape.
To space 3 arms evenly, you rotate each one 90 degrees apart.
TinkerCAD remembers your last action when you press Ctrl+D again.
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Knowledge Check
+15 XP
How many degrees apart should you space 3 arms evenly around a circle?
A120 degrees
B90 degrees
C180 degrees
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Add the Center Hole
Create a hole for the bearing using a hole cylinder
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Goal for this step
Add an 8mm diameter hole through the center of the spinner for a bearing.
Create the hole
1Drag another Cylinder onto the workplane and resize it to 8mm x 8mm x 10mm (slightly taller than the spinner).
2Position it in the exact center of the spinner body.
3Use the Align tool: select both the hole cylinder and the main body, then click "Align" (L key) in the top toolbar.
4Click the center dots on both the X and Y axes, the hole cylinder snaps to the exact center.
5Now the key step: select the small cylinder and look at the top-right of the screen. Click "Hole", the shape turns translucent with stripes.
6The shape is now a "Hole", when grouped with other shapes, it will cut through them like a cookie cutter.
What you should see: after clicking "Hole", the small cylinder turns grey with stripes. From the side (click a side face on the ViewCube) it should stick out slightly above and below the body.
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Making the hole cylinder taller (10mm) than the spinner (8mm) ensures it cuts all the way through. If it's the same height, you might get a thin layer left at the bottom.
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Fill in the Blanks
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To cut a hole through a shape in TinkerCAD, first change the shape to a , then all shapes together.
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Knowledge Check
+15 XP
Why do we make the hole cylinder 10mm tall when the spinner is only 8mm?
ASo it looks taller than the spinner
BTo ensure the hole cuts completely through, no thin layer left at top or bottom
CBecause bearings are 10mm tall
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Group Everything Together
Combine all shapes into one solid design
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Goal for this step
Group all shapes into one unified object and verify the design looks correct.
Group and verify
1Press Ctrl+A to select all shapes on the workplane.
2You should see all shapes highlighted, the main body, 3 arms, and the center hole.
3Click "Group" in the top toolbar (or press Ctrl+G). All shapes merge into one!
4The hole cylinder cuts through the body, leaving a clean circular hole in the center.
5Rotate the view to check your design from all angles, it should look like a 3-armed spinner with a center hole.
6If something looks wrong, press Ctrl+Z to undo the grouping, fix the issue, then group again.
What you should see: one solid shape in a single colour with a clean hole through the middle. Orbit around it (right-click + drag), it should look like this from every angle, just 8mm thick.
✅Checkpoint: if you can still click an arm and move it on its own, it didn't group. Select everything (Ctrl+A) and press Ctrl+G again. If the hole didn't appear, the small cylinder probably wasn't set to "Hole", undo, click it, choose Hole, and re-group.
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After grouping, you can change the colour of the entire spinner by selecting it and choosing a colour from the Shape Properties panel.
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Put It In Order
+15 XP
Put these in the correct order to group shapes:
Click Group or press Ctrl+G
Press Ctrl+A to select all shapes
Check the design from all angles
Verify all shapes are highlighted
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Knowledge Check
+15 XP
What happens to the "Hole" shape when you Group it with solid shapes?
AIt disappears completely
BIt becomes solid
CIt cuts through the solid shapes, creating a hole
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Export as STL
Download your design ready for 3D printing
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Goal for this step
Export your finished spinner as an STL file and understand basic 3D print settings.
Export and print
1Click the "Export" button in the top-right corner of TinkerCAD.
2A dialog appears with format options. Choose "STL", this is the standard format for 3D printing.
3Click the download button. Your file saves as a .stl file.
4This STL file can be opened in any 3D printing software (called a "slicer") like Cura or PrusaSlicer.
5In the slicer, you'd set: Layer Height (0.2mm is standard), Infill (20% is fine for a spinner), and Material (PLA is easiest).
6The slicer converts your 3D model into instructions the printer can follow, layer by layer.
Export → .STL. The file lands in your Downloads folder as My Fidget Spinner.stl. That single file is everything a 3D printer (or an online print service) needs.
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Parent note: If you don't have a 3D printer at home, many libraries and makerspaces have them available for free or low cost. Some online services like Shapeways will also print and ship your design.
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True or False?
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STL is the standard file format for 3D printing.
You need to download software to use TinkerCAD.
A slicer converts your 3D model into instructions for the printer.
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Final Knowledge Check
+15 XP
What file format do you export for 3D printing?
ASTL
BPNG
CPDF
🛠️ Printed it and something's not right?
The spinner barely spins or wobbles. The arms carry the momentum, so they must be evenly spaced (exactly 120°) and identical. If one arm sits closer to the centre than the others, the spinner is out of balance. Re-check step 6 and re-print.
It came off the printer in separate pieces. The arms were not overlapping the body when you grouped. In TinkerCad the arm circles must clearly cross into the body circle (step 5), touching edges are not enough.
The centre hole is too tight for my bearing or axle. Printers shrink holes slightly, an 8mm hole often prints at 7.8mm. Either scale the hole up to 8.4mm in TinkerCad and re-export, or gently twist a drill bit through by hand.
The edges are rough or the bottom is wavy. That is a printer setup issue, not your design. Ask whoever printed it to level the bed and print with the flat face down at 0.2mm layers.
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You Designed a Working Fidget Spinner!
Amazing, you've learned the TinkerCAD interface and designed a properly-balanced 3D-printable fidget spinner. Now try Episode 2!
