Create custom model for SITL

I solved but can’t remember exactly but like @Jaeyoung-Lim said:

  1. First check your mixer and airframe. Most importantly check mixer.
  2. Go step by step and if you are getting specific error. Committing here will be helpful.
  3. For me my sdf wasn’t good enough so be sure about your model’s sdf. Check difference with same models and be careful about PX4 version