Flexi-wing airplane model with flapping wings and spinning propeller when the button is pushed.  Model size: 180mm wingspan, 130mm nose to tail, 50mm tall.  All parts need to be printed at 0.15mm layer height with 0.4mm nozzle or better to prevent parts from fusing together.  Recommend two prints, the first with the Top and Bottom  main body halves (with print-in-place wings and internal mechanisms) printed with 20~30% infill.  Second print with the Prop, Ball Joint, Output Shaft and Assembly Tabs at 100% infill to maximize the weight (for better spinning effect) and strength.  Pictured model printed in approx 7 hours on a Prusa MK3 in PLA and PLA+ with 0.4mm nozzle. 

See assembly tips image for how to put the model together.  Only use the smallest possible amount of glue in assembly to prevent fusing any of the moving parts together and do not glue the output shaft to the ball joint part.