Lightweight Quadcopter Frame Design (Carbon Fiber & 3D Printed Components)

grabcad

This is a quadcopter frame design that consists of carbon fiber rods and 3D printed components, with the goal of being lightweight without sacrificing strength and durability. The frame is currently dimensioned for 5 inch propellors with 27 mm diameter motors, but it can easily be modified to fit somewhat larger propellors, and different motor sizes. These dimensions and more can be modified in the global variables. A multi-body part design approach was used for this quadcopter frame instead of an in-context assembly approach. After modifying features on a component, each body can be re-saved into individual part files, and then saved as STLs if desired.The current frame design weighs about 50% less than any standard purchasable frame in this form factor. This design is called V1, as I will make an improved version at some point. One of the main design considerations is to minimize the bending and direct shear stresses on the carbon fiber rods. Pure tension and compression are the most desirable here due to the carbon fiber's anisotropic properties. The V2 version will use fewer carbon fiber rods, have an easily removable top, improved propellor clearance, battery shielding, and possibly more improvements.The V1 frame design uses 5 - 240mm long 3mm diameter carbon fiber rods cut into smaller pieces, or equivalent lengths. The insertion holes in the plastic components are all made to be undersized after printing, and then the holes can be drilled to size with an approximately 3mm diameter drill bit. Initially, the holes were modeled to all be press-fit after printing, but there is too much variation between prints and the hole orientations to feasibly do this. So, the holes can be drilled out, and then the rods can be glued into the holes. Superglue can be used, but super glue can possibly cause embrittlement with plastics such as polycarbonate. The notches on the outside edge of each motor mount are for tensioning a string around the entire frame to help hold everything together. The slots through the base piece around the control board mount point are for a velcro strap to hold a battery. The centered hole on the top of the frame is for mounting a camera. The hole could be threaded, or a heat-set insert could be used.When printed with ABS at 20% infill, all of the 3D printed parts weigh about 29 grams combined.