From 'I Just Want a Piggy Bank' to a CNC-Ready Matrix Generator
Most of what I write about here is software development. But in my free time, I also like to mess around with a CO2 laser CNC machine.
Recently I wanted to build a piggy bank (saving box) where you track progress by crossing out a number grid until you hit a target amount.
The Problem: Templates Exist Until They Don’t
Online templates work only for common totals. As soon as you need custom values, they break down:
- You want a custom target (for example: 750, 1350, 4200)
- You want your own grid size (rows and columns based on your physical design)
- You want specific denominations (for example: 1, 2, 5, 10, 20, 50, 100)
As software engineers, we usually do not stop at “close enough.” We build what we actually need.
What I Built: Piggy Bank Matrix Builder
Piggy Bank Matrix Builder generates a CNC-ready SVG matrix using your target sum, chosen numbers, and grid size.
What It Does
- Set a target sum
- Provide numbers (comma-separated) as denominations or any custom values
- Choose rows and columns
- Adjust a small-number bias to influence distribution
- Export as:
- SVG (for laser/CNC)
- CSV (for further edits)
Why This Was a Good Fit for Vibe Coding
This was a perfect vibe coding project for me:
- Performance is not a hard requirement
- The software is not safety-critical
- I do not usually write in this language stack
- I can verify results quickly by checking totals, previewing SVG, and testing on real material
That makes AI-assisted iteration fast and practical, with clear validation at each step.
Video Version
From Idea to Working Tool With Codex: Target Piggy Banks
Try It
If you build something with it (different currencies, weird denominations, alternative layouts), I would love to see it.