[felooboolooomba]

I highly recommend using a CAD with constrains support, like the sketcher in FreeCAD. Once get the hang of it, you'll never, ever go back.

[devttyeu]

Mmm FreeCAD you say, let's see.

[felooboolooomba]

Having the sketcher as a web app could be incredibly useful, especially if it could save as PDF, SVG and download your current sketch as JSON or something so it could be loaded again.