With the members of DART we decided to use a system for the Rocket flaps that can be reused quickly for any launches in succession. In addition, we have projected it so that you do not have to access the inside of the outer carbon coating because, being the diameter of the rocket small, it is difficult to manage the internal parts between the engine and the case. Then, we found a way to anchor the system to the outer surface by rolling the sled. Consequently, this approach allows you to remove and insert the inner core and to glue a father and mother lining of the fin, or its aerodynamic surface, represented with red color in the video. In addition, talking about the materials , the flap will be in petg and the core and sled in steel laminated then with carbon.