Tools that make the whole part

I had a project that needed a large, custom timing belt pulley. In the age of vibe coding, the obvious question was: why not make my own tool to design belt pulleys?

That led to a deep dive into how timing pulleys are designed. My first tool was basic, and it taught me how much I dislike tools that are an 80% solution — the user inevitably does the other 80% of the work to get a part they can use.

So the final design focused on the interface, and on tools that produce complete parts: parts you can import into CAD or print directly, plus intermediate files (DXF, SVG) for when you want to build something custom of your own.

The philosophy behind every tool

• Make useful parts. A finished pulley — bore, hub, set screws, flanges — not a toothed disc.
• A focused interface. Every control is there to make that one kind of part.
• Sensible, adjustable defaults. Opinions from the standards, which you can override.
• Exports as jumping-off points. STEP, STL, DXF and SVG for whatever comes next.
• In the browser. One tool that works alongside any CAD package, on any computer.

What's next

The Timing Pulley Generator is live. The Sprocket Designer and Gear Designer are close behind, and E-Box Designer — parametric 3D-printed enclosures for electronics — is in the works. They're all CAD tools I kept needing myself.

If one of them is missing something, use the ⚠ button in its title bar or get in touch. Feature requests really do shape what gets built.

— Chris Myerchin

CheapCAD Tools is published by Myerchin Enterprises Inc., Bellevue, Washington.