Solar CNC cutter

Laser CNC cutters are awesome, but very expensive. Most of this cost is a hefty CO2 laser and accompanying power supply. Let's do away with this expense, while making it vastly more efficient as well.

Start with a few big Fresnel lenses to collect sunlight. Light duty laser cutters use a paltry 40 Watt laser, while sunlight gives around a kilowatt per square meter, free of charge. Focus this light down a mirrored pipe to the machine, and you have a source of bulk concentrated energy. Add a couple photovoltaic panels while you're at it, and make the CNC part of the machine solar powered as well.

It won't be coherent, but with good optics you can focus it to a small blindingly bright spot. Laser cutters typically use a nonparallel focused beam anyway. To modulate the beam, simply move a small mirror into its path. It won't operate at night, but overcast days shouldn't be a problem for lighter duty work. And you certainly can't beat the free massive power influx on a sunny day.