CAD Models of F651 Drone
You can download these CAD models and 3D print it to make the drone.
The Gripper system consists of two claws as shown here.
The CAD models were also tested for FEA 
If you used this code, kindly consider citing the paper: E. Andersson and A. Bogga, ‘Hexacopter with gripping module’, Bachelor's Dissertation, Halmstad University, Sweden 2018.