TINKER PiEDESIGN IN INDIA

Build an arch bridgeTinkerPieCAD tutorial 10 of 10 · Intermediate · 15 minutes

Cut a round arch through a thick beam by turning a cylinder on its side.

Open the finished design in TinkerPieCAD (free, runs in your browser)

What you will learn

Shapes you need

BoxCylinder (hole, rotated)

Steps

  1. The deck

    Add a Box 100 × 24 × 26 at Z 13 (grey).

  2. The arch hole

    Add a Cylinder, make it a Hole, Size 36 × 36 × 30. Set Rotation X to 90 so it lies on its side.

  3. Position it

    Set its Position to X 0, Y 0, Z 0. The top of the circle reaches 18 mm, leaving 8 mm of deck above the arch.

  4. Group

    Select both and press Group. A tunnel appears through the bridge.

  5. Test it

    Use the Front view to see the arch shape. Export it.

Why it works

An arch spreads weight outwards and is one of the strongest shapes. Roman bridges built this way are still standing.

Challenge: Cut a second, smaller arch on each side to make a three-arch bridge.

All sizes are in millimetres. Type exact numbers in the right-hand panel. Press Export to get an STL file for a 3D printer.

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