The present invention relates to a winding device and a flying toy ornithopter device which employs the winding device. The solar cell is mounted to a substrate and connected via wires through the hollow beam to the motivator. Also disclosed is, for the production of the doctor bed, a material or a material combination selected including in a first variant of a homogeneous mixture of 70 to 99. The base includes an aperture through the opposing face of the base for receiving audio signals into the chamber. The end-mill comprises a cylindrical shank portion connected to a first cutting portion provided with a plurality of spaced-apart cutting teeth and a second portion provided with a plurality of different spaced-apart cutting teeth.