This is a work in progress that I wanted to add to show some of my 3D and fabricating skills. I have two current designs that I am working on.
DESIGN ONE: 3D printed (orange and red)
Design TWO: Cabon fiber composit (shown in black).
This is one of the 3D printed arms for the quadcopter shown with one of the motors mounted. This is the rear of the arm. The orange plastic wraps around the front of the motor to protect it from damage.
This is a detail of the motor being mounted with M3 nylon screws and nuts. The 3D printed peice has 4 holes but I am only using two of them to mount the motor. The nylon screws are used as break-away features to protect the motor in a hard crash and that is why I am only using two.
Here is a detail of the 3D printed arm. The most popular 3D printing file format is STL. STL files only describe the outside surface of the part. To increase strenth and funtionality I created a hollow tube that passes through the entire part. The tube serves two purposes. It allows the wires for the motor to be protected from damage and also it allows the part to have a spar inside the part for added strenth.
Here is a detail showing the inside of the arm. Notice how the tube runs the entire lenth of the arm. The part, although visually bulky, is mostly hollow -- 90% hollow in fact. With a large cross section and internal spar this quadcopter arm is very rigid compared to other designs currently available. This part only weighs 76 grams (.4oz).
Here the parts are shown with a 12oz can of soda to give you a better idea of the scale. The propeller is 5 inches in diameter.
This is my second design which is made from a CNC (computer numerial control) router driven by a computer to cut the foam core. The core was then covered with carbon fiber cloth and put in a vacuum bag. Once the vacuum bag was sealed epoxy was mixed and drawn into the bag infusing the carbon fiber. This is known as "resin infusion". The part was allowed to try overnight in the vacuum.
This is the finished carbon fiber quadcopter frame. Similar frames also made from carbon fiber, but without the foam core weigh 170 grams. This frame as shown weighs 76 grams (2.7 oz).
