Create ArduCotpter model for gazebo with SITL

hello,guys. l have used gazebo with SITL to simulate arducopter in indoor scene,during the simulation, l use the model given in tutorials:Using Gazebo Simulator with SITL — Dev documentation?
highlight=gazebo. but the model’s size is not fit with my real UAV, l have tried to modify the given model “iris_demo”,it doesnot seem feasible. so can l create my own model by using other software like blender,solidworks and how can l make it link with ros?
Thanks in advance for all the help!