Browser-based open-source CAD is finally good enough to design real robot parts, and I’ve switched my entire bot-building workflow to prove it.
For years, I designed every bracket, sensor mount, and chassis component in desktop CAD software. FreeCAD was my go-to—it’s powerful, free, and runs on anything. But every time I wanted to iterate on a design while testing code, I’d alt-tab between my IDE, terminal, and CAD window. The friction added up. When I discovered CADmium and revisited OpenSCAD’s browser implementations, I realized something had shifted: these tools weren’t just experiments anymore. They were legitimate design environments that fit perfectly into a bot builder’s workflow.
The Case for Browser-Based CAD
Here’s what changed my mind: integration. When you’re building bots, you’re constantly moving between code, documentation, datasheets, and 3D models. Having CAD in a browser tab means it lives in the same environment as everything else. I can have my Python control code in VS Code, my CAD design in another tab, and my component specs in a third. No window management gymnastics.
CADmium caught my attention because it’s built specifically for the web. It’s not a desktop app ported to run in a browser—it’s designed from the ground up for browser architecture. That means it loads fast, saves to the cloud naturally, and shares designs with a URL. When I’m documenting a bot build tutorial, I can link directly to the CAD model. Readers can open it, rotate it, measure it, and fork it without installing anything.
OpenSCAD’s browser versions take a different approach. Instead of traditional CAD modeling, you write code that generates geometry. For bot builders who already think in Python or JavaScript, this is natural. I can parameterize a sensor mount, change one variable, and regenerate the entire assembly. Better yet, I can version control my CAD files in Git alongside my bot’s firmware.
What Actually Works
I’m not claiming browser CAD replaces everything. FreeCAD still wins for complex assemblies with hundreds of parts. LibreCAD remains my choice for precise 2D technical drawings. But for the 80% of bot-building CAD work—designing mounts, brackets, enclosures, and simple mechanical parts—browser tools handle it.
I recently designed a complete sensor array housing in CADmium. Four ultrasonic sensors, two cameras, and a LIDAR mount, all in one printable part. The design took about two hours, and I never left my browser. When I needed to check a sensor’s datasheet, it was one tab over. When I wanted to verify mounting hole spacing against my PCB design in KiCAD, I had both open side-by-side.
The real test came when I shared the design with someone building a similar bot. I sent a URL. They opened it, modified the sensor spacing for their hardware, and exported an STL. No “What version of FreeCAD are you running?” No “Can you export this in a different format?” Just a link and a working model.
The Open Source Angle
Both CADmium and OpenSCAD are open source, which matters more than you might think. When I hit a bug in CADmium’s constraint solver, I could look at the code, understand what was happening, and work around it. When I wanted OpenSCAD to export in a specific format, I could check if someone had already written that exporter.
FreeCAD and LibreCAD have massive communities and decades of development. They’re mature, stable, and feature-rich. Browser-based tools are younger, but they’re evolving fast. The fact that they’re open source means they’re not dependent on a single company’s roadmap or business model. They’ll exist as long as people find them useful.
Where This Goes Next
I’m not abandoning desktop CAD entirely. Complex assemblies still need FreeCAD’s power. Precision 2D work still needs LibreCAD’s tools. But for daily bot-building work—the quick mounts, the test fixtures, the iterative prototypes—I’m staying in the browser.
The workflow integration alone justifies the switch. When I’m writing a tutorial about building a line-following bot, I can embed the CAD model directly in the article. Readers can inspect it, modify it, and download their version without leaving the page. That’s not possible with desktop CAD.
Browser-based open-source CAD isn’t the future—it’s the present. And for bot builders who live in their browsers anyway, it’s exactly where CAD should be.
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