Concrete Keyboard Lecture Notes

Introduction

• Discussion about the desire for a heavier keyboard feel.
• Introduction of the concept: Concrete keyboard.

Previous Projects

• Mention of past projects:
  • All-resin keyboard
  • All-wood keyboard
• Challenge: Creating a keyboard from concrete.

Project Challenges

• Concrete's characteristics:
  • Strength vs. brittleness (tends to crack under strain).
  • Concerns about durability of key caps made of concrete.

Materials Used

• Concrete Mix: Vinyl concrete patcher (designed for thin applications).
• Strengthening Additives:
  • PVA glue
  • Fiberglass
  • Additional sand

Key Cap Design

• Creating a stem using plastic 3D printing.
• Use of a vibrator to remove bubbles and ensure concrete fills molds properly.
• Experiment with adding PVA glue to concrete mix to enhance strength:
  • Recommendation: Replace 10-25% of water with PVA glue.
  • Adjustments made during the mixing process.

Molding Process

• Vibration helps concrete settle and fill all crevices in the mold.
• Pressure pot used to minimize air bubbles, thereby potentially increasing strength.
• Observations during concrete mixing and pouring.

Testing Strength

• Discussion on results from different mixes:
  • Control concrete (no additives)
  • Concrete with sand
  • Concrete with fiberglass
  • Concrete with PVA glue
• Results:
  • All types held up well under typing conditions.
  • PVA glue mix was the most promising due to strength and aesthetics.

Final Assembly Discussion

• Need for a concrete case for the keyboard.
• Modifications made to molds for better strength.
• Creation of custom molds using Legos.
• Potential for additional issues with thinner tops on some molds.
• Solutions: Use resin to reinforce thinner tops before recasting.

Conclusion of Process

• Importance of experimenting and learning through the project.
• Final assembly of keyboard components, including a wrist rest made from concrete.
• Discussion about the final aesthetic and functionality of the concrete keyboard.
• Emphasis on the project's difficulty but rewarding outcome.