For this purpose, we can use different materials, such as metal, plastic, or wood. These materials will differ based on how sturdy you intend the drone to be.

They must be in accordance with the size of your drone. Multi-rotor drones produce greater speed and ensure a stable flight, as each rotor works with other’s thrust points. For better performance, it would be better to get carbon props.

The next thing we need to do is drill the holes in the frame for the motors, according to the distance between the screws holes on the motors.

After mounting the motors, we also have to mount the speed controllers.

more research need to be done , as material will decide the shook absorbility . Also I'm planning to add a non contact charging surface, so that when drone land on landing station , it can automatically get charged.

This will play a vital role in maintaining connections between several sensors involved in OBC (on board chip) and some research have to be done on deciding protocol to maintain communication between police station and drone.

This electronic system allows a drone to be stable in the air while flying and processes all the shifts and changes in direction and the wind.

There are several open source available to fullfill the purpose.

This depends on the budget and how much resolution needed and for what type of work.