One of the most popular types of Unmanned Aerial Vehicles, UAV, is the quadrotor helicopter, commonly known as quadcopter. This work seeks to document the lessons learned by the authors while attempting to build their own quadcopter for further studies of stability control, instead of using a commercial quadcopter for the same purpose. The article describes the process on how we can build our own quadrotor, applying a mechatronic design methodology by concurrently taking into account mechanical, electronic, software and control component design. The paper also presents the simulation results for altitude control (pitch and roll). The results of this investigation include recommendations for proper selection of components such as motors, propellers, batteries and electronic speed controllers so that anyone interested can build his/her own quadrotor.