Hasty Briefsbeta

Designing a Mechanical Calculator

18 days ago
  • #Mechanical Engineering
  • #DIY Projects
  • #3D Printing
  • Author decided to 3D print a mechanical calculator, combining old and new technology.
  • Explored existing 3D calculator designs, from simple to complex, like the Curta Type I replica.
  • Wanted a modular and simple design but found only complex modular designs based on Pascal’s calculator.
  • Chose to design from scratch, starting with a basic 10-tooth gear system for number display and carry function.
  • Initial prototype had issues with gear teeth not interlocking correctly.
  • Discovered involute gears, an optimal tooth shape, and used CAD libraries to design better gears.
  • Realized a miscalculation in gear movement: gears turned two teeth instead of one per full tooth pass.
  • Redesigned with 30-tooth gears and a protruding carry tooth for accurate movement.
  • Solved gear slippage with c-clips initially, later improved with a peg-based fastener system.
  • Final version is stable and shared on Printables for others to use.