Tools that make the whole part

I needed a large, custom timing belt pulley to prototype a manufacturing idea I was thinking about, and I couldn't find what I needed online. I'm a software engineer, between jobs with time on my hands. Why not brush up on AI coding tools and make my own pulley design program?

That turned into a weeks-long deep dive into how timing pulleys are actually specified: tooth profiles, belt standards, how belt and pulley fit together. My first tool worked, but it only produced a 2D drawing. Turning that into a useful pulley took hours of CAD work. It reminded me how much I dislike tools that stop 80% of the way to a useful solution. The last 20% of the design ends up being a big time suck for the person who has to finish the job.

So I spent the next few months rebuilding it around a simple interface focused on building one thing, timing pulleys at first, and outputting a completed part. That means a file you can import into CAD or send straight to a 3D printer, plus DXF and SVG for when you want to build something of your own. Then I printed the parts and ran them on real belts to make sure they work.

The same approach became the Sprocket Designer, the Gear Designer, the Worm Gear Designer, the Bevel Gear Designer and the Planetary Gear Designer.

Another thing I don't like is software subscriptions. I hate being stuck renewing software I only use once or twice a year. So with CheapCADTools, designing is free, and you only pay for the files you download, with tokens you can buy for as little as $2. They don't expire as long as you sign in once every five years.

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, the Sprocket Designer, the Gear Designer, the Worm Gear Designer, the Bevel Gear Designer and the Planetary Gear Designer are live, 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, click the bug icon in its title bar, tick Feature Request and tell us what you want, or get in touch. Feature requests really do shape what gets built.

— Chris Myerchin

CheapCADTools is published by Myerchin Enterprises Inc., Bellevue, Washington.