To design a parabola, make this very simple drawing tool which is able to construct any parabolic curve with ease. Instructions include photographs. The precision plans here help you build a parabolic dish solar cooker using a simple wood model to assure the exact parabolic shape of the mirror. Precision is very important to get a small focal sun-spot and a high cooking temperature. With an off shape mirror the focal concentration becomes spread and eventually uneven distributed resulting in a cooker which heats up very quickly but does not reach higher temperatures than e.g. 95°C.