CAD without CAD? No, it's not a Zen koan, it's maker.js, an open source project from Microsoft Garage that lets you create CAD designs by just tweaking a few settings. For example, the ring designer shown above lets you make rings or washers of any size by just entering an inner and outer diameter. Best of all, it outputs DXF files compatible with Big Blue Saw's online quoting system.
Here's another useful tool from maker.js: a sign creator with support for stencil fonts, rounded corners, and mounting holes.
There's also double pipe clamp builder. I'm told that this was inspired by the custom clamp from our articles on designing for waterjet.
Check out more things you can design on the maker.js demo page.