There are three options for a quadcopter frame you can purchase a fully built frame, a kit which requires some assembly or you can build a frame from scratch. There are many types of materials that can be used to build a frame including wood, plastic, fiberglass, carbon fiber and aluminum.
I decided to build my frame from scratch and will be using 20mm x 20mm square aluminum tubing for the arms and clear 5mm acrylic for the center piece.
First off I had to work out how long the arms needed to be. The props measure 250mm since the motors will be mounted on the ends of the arms only half the length of the props will pass on the inside of the quad. Then I worked out how much space would be needed in the center for the wiring and circuit board.
The arms will be 240mm long which will leave enough room between the props and have space in the middle to mount all the other components. I cut the arms to the required length using a hacksaw then lined them all up to make sure all four are equal lengths.
Next I mounted the motors on the end of each arm, I marked the center of the aluminum square tubing placed the motor on the center line then marked the mounting hours and drilled them out. I fixed the motors in place using self tapping screws.
For the center place I cut a 140mm x 140mm square out of the 5mm acrylic then cut off the corners 10mm in. The next challenge is to mount the arms to the center plate and make it all square and balanced otherwise the quad will be off balance and hard to fly. I marked the center of the square then marked halfway down all four sides. Using a ruler I drew a line from the outer markings to the center of the square and this gave me the center like to mount the arms.
Next was to measure out the wholes to screw the arms to the center plate, I measured equal distances on the center plate and arms. Then drilled the holes and check if they lined up then screwed in place using self tapping screws. Once I had attached all four arms I measured the distance between the motors and the edge of the center plate to make sure they were equal distances apart.