Take it camping, to the beach, to your survival hut for cooking after the collapse of society. Solar cookers work in hot or cold weather, from about 1 hour after sunrise until 1 hour before sunset.
This model is a small prototype of a parabolic cooker, measuring only 40cm in diameter. As you can see in the video, it sets a piece of paper on fire in seconds.
I've included a 1-meter version that equals the size of many commercially-available solar cookers, but I have yet to design the support structure for that one. The large one also would take around 3kg of plastic to print.
In addition to the printed parts, the only parts needed are M3 screws and nuts, 5/16" (M8) nut and bolt, a small piece of a mylar rescue blanket (cheap online, under $1) and spray adhesive. Watch the video for how to make it shiny: https://youtu.be/fWK3PbSSsjs
The only part requiring support during printing is the hub.
USE DARK SUNGLASSES. It's REALLY easy to blind yourself otherwise.