Interlocking Heart Keychains

Today you will make a set of 3D interlocking heart keychains using 123D Design (free to download) and a 3D printer.

Tips

The 3D printer prints with one color of filament, which is preloaded by staff.

Feel free to talk with or assist your neighbor in this informal learning environment.

2. Try out the Sketch Tools 

Sketches are 2 dimensional shapes that you extrude to produce 3D objects.

POLYLINE

• Hover over Sketch > click Polyline.

• Click anywhere on the grid to activate the tool, click again to create your first point.

• Move your cursor, a straight line segment will extend outward, click to set the segment.

TIP: Your cursor will snap to grid intersections. Use this feature carefully to create symmetrical shapes!

• Click around to add points and segments to build up a shape. 

• Click your first point to finish the sketch, hit the ENTER key (or click the green checkmark) to turn off the tool.

SPLINE

 • Hover over Sketch > click Spline.

 • Click anywhere on the grid, click again to create a point.

 • Add points and segments as before, notice that the segments curve between points.

 • The entire shape readjusts as you add to the sketch. To preserve curves, use the Spline method in step 3.

 • Click your first point in the sketch, hit ENTER.

 • Click and drag a selection box around your practice shapes, hit DELETE on your keyboard to remove them.

3. Draw a full heart with Polyline -or- Spline

If Using Spline...

• Click Spline

• Sketch the first heart half

• Turn off the tool

•  Click Spline again

•  Click on the heart half to add to the sketch (it will glow green)

•  Click on the first point of the heart half (where the heart dips near the top)

•  Add points and segments as before

•  Click the bottommost point

•  Turn off the tool

4. Check your heart size

To guarantee that your model will print within the allotted 15 minutess, it has to be 40mm x 50mm or smaller.

Every square in the grid is 5mm x 5mm, so your heart should fit within an 8 box x 10 box area.

•  Click the heart to select it, hover over the gear box menu, click Scale.

•  Click-drag the arrow to the left. Moving to the right enlarges the sketch.

•  A second heart will appear inside your original sketch - it is a scaling preview.

•  Once the preview is an appropriate size, hit ENTER to set the scale/turn the tool off.

5. Split your sketch in half

•  Click Polyline, click the edge of the heart to add to the sketch.

•  Click the point or edge where you want the division to begin.

•  Set points in a zigzag or add a single segment through the center.

•  Click the edge where you want the division to end, hit ENTER.

*Part of the polyline might stick outside of the heart sketch.It will not cause any problems in later steps.

6. Extrude the heart halves

•  Click inside a heart half to select all of its surrounding segments.

•  Hover over the gear box > Click Extrude.

 •  Type 4 to create the Z axis (height). The default unit is mm.

 •  Hit ENTER to set the dimension and turn the tool off.

 • To see the dimension, right-click and drag to change your perspective.

•  Click and drag your extruded heart away from the sketch - keep it nearby.

 • Extrude the other half to 4mm, turn the tool off.

 • Hover over the  eye in the right-hand menu > click Hide Sketches.

7. Create and position cylinders for holes

• Return to the TOP face on the View Cube.

•  Hover over Primitives > Click Cylinder.

•  Type 1.5 to set the radius of the cylinder. It will appear as a circle in this perspective.

•  Move your mouse, position the cylinder outside of a heart half, click to set it.

•  Click and drag the cylinder to where you want a hole.

•  Create a second cylinder, position it within the other half.

•  Right-click and drag to see the dimension.

8. Subtract the cylinders to create holes for the key rings

•  Hover over Combine > click Subtract.

•  Click a heart half.

•  Click the intersecting cylinder.

•  Hit ENTER to cut/remove the cylinder. 

•  Subtract the cylinder from the other half.

9. Save your file to the Desktop

•  Hover over AUTODESK 123D DESIGN (top left of the window) > hover over Export as 3D… > click STL.

•  Choose Coarse under Mesh Tessellation Settings, check the Combine Objects box.

•  Use your name for the file name, Save to Desktop.

10. We will guide you through processing your file for a 3D printer.

11. Survey - We'll direct you to a survey to help us improve our workshops and learn about makerspaces in libraries.

Thanks for visiting!