2. Activity of Day 2¶
Digital Modeling for Fabrication
Overview¶
Day 2 focused on digital modeling for fabrication, introducing both 3D parametric modeling and 2D vector design. The goal was to understand how simple, fabrication-ready geometry is created using appropriate software tools.
Two modeling activities were completed:
A 3D L-Shaped Mounting Bracket using FreeCAD
A 2D Press-Fit Box Panel using Inkscape
Activity 1 – FreeCAD Model¶
L-Shaped Mounting Bracket (3D)¶
Design Goal
Create a simple L-shaped mounting bracket that demonstrates basic 3D modeling operations used in fabrication.
Design Characteristics¶
- Two flat faces at 90°
- Two circular holes for screws or bolts
- Simple geometry with no complex curves
- One filleted corner for safety and manufacturability
Implementation¶
Modeling Workflow (FreeCAD)¶
The following steps describe the process used to model the L-Shaped Mounting Bracket in FreeCAD.
Note
- Created a new sketch on the reference plane
- Drew an L-shaped 2D profile
- Applied geometric constraints to control the orientation and relationships between sketch elements
(horizontal, vertical, parallel, and perpendicular). - Applied dimensional constraints to define exact sizes such as lengths, widths, and thickness.
- Ensured the sketch became fully constrained, preventing unintended movement (degrees of freedom = 0)
- Used the Pad tool to extrude the fully constrained 2D sketch into a 3D solid.
- Selected the appropriate face and sketched two circular profiles using the circle tool.
- Applied an equal constraint to ensure both holes had identical diameters.
- Positioned the holes symmetrically using geometric constraints.
- Added dimensional constraints to set hole diameters suitable for standard fasteners and fully constrain the sketch.
- Used the Pocket tool with the parameter set from back face to front face to create through-holes.
- Once that was done, applied Chamfer to the two circular edges of the screw holes.
- Selected the sharp edges to rould of the bracket and
- Applied Fillet to remove the sharpness and make them smooth.
Download reference¶
Download the FabLab Day 2 Activity 1
Activity 2 – Inkscape Model¶
Press-Fit Box Panel (2D Vector)¶
Design Goal
Create a 2D press-fit box panel using vector geometry that can be laser-cut and assembled without fasteners. The focus is on dimensional accuracy and material-aware design.
Design Characteristics¶
- Flat rectangular panel
- Rectangular slots cut along the edges
- Slot widths sized to match material thickness
- Geometry designed to slide and lock with other panels
- Entirely 2D vector-based design
Key considerations:
- 1:1 scale design to ensure accurate real-world dimensions
- Use of clean paths for precise vector geometry
- Slot accuracy – Proper sizing for press-fit assembly
Modeling Approach (Inkscape)¶
- Created rectangle shapes representing box panels.
- Added tabs that allow the boxes to fit into each other.
- Used the Union tool in Inkscape to merge the tabs and box shapes.
- Ensured the sizes were correct so the boxes can fit into each other.
- Used the Difference tool to create holes in the box panels.
