Around here, and in the maker community in general, most of the projects we see are fairly limited in size. It’s unusual for us to feature anything bigger than a kitchen microwave oven. But, that doesn’t mean that there aren’t people out there building large contraptions—and building at that size requires fabrication on a greater scale than the desktop 3D printers and laser cutters we’re used to can accommodate.
When you’re fabricating creations the size of a compact car, you’re almost certainly going to be cutting parts from sheet material like plywood, metal, or acrylic. That material can be cut with lasers, plasma, or waterjet, but CNC routers are by far the most common and versatile tool for the job. If you’re going that route, the CNC router has to have a work area at least as large as the sheet material you’re cutting.
To handle those large sheets, maker Nishantkinshu built a massive 5 foot by 10 foot CNC router. That’s neither a trivial nor cheap thing to do. The table for the router was made from 40x80mm aluminum extrusion—not as sturdy as steel, but easier to work with. Because of the size and weight of the gantry (and the loads it would be under), a rack and pinion drive system was used with Nema 34 stepper motors.
The one weak spot of the build is the Z-axis carriage, which was built with acrylic. That was somewhat of a compromise, but aluminum parts were unavailable. At $3,500, this would be a pretty big investment for any hobbyist, but is still much more affordable that similarly sized commercial models.