Make drone model for gazebo

So I have been studying how you can simulate a quadcopter with gazebo and sitl, and now I want to make my own model of the drone I am making for college.

I have a CAD with the drone complete already, so what are the next steps or the best steps? Do I need to use blender?

It’s usually easier to modify an existing model than start from scratch, at least to start with. The ardupilot_gazebo package contains an example model iris_with_ardupilot and the Gazebo tutorials has a category on how to build a robot.

To get the robot working the important features are the model dimensions and mass distribution. You don’t need the CAD model for this and the model structure should be built out of primitives (boxes, cylinders and spheres). Once you have the kinematics and the inertia correct you can then dress the model up with the visuals from your CAD model. You’ll need to export the parts as STL mesh files and may need to tinker about with them in Blender to alter the origin as this can help when aligning them with the Gazebo model geometry.