Quadcopter Arm Joints

thingiverse

I'm illustrating some of my ideas on how quadcopter arm joints can be improved through the included STL files.\r\n\r\nCommercial designs with separate arms often have them sandwiched between carbon fiber plates, or a plate and an aluminum brace, resulting in mechanically weak joints that are also weighty due to multiple bolts per arm.\r\n\r\nThe interlocking joints presented here offer higher mechanical strength, reducing the need for bracing - possibly only one plate and fewer bolts are required: three (or two) for joining two arms together, and four bolts when all four arms are joined.\r\n\r\nThe symmetrical design ensures that all arms in a set of either two or four are identical.\r\n\r\nCombining finger and lap joints provides added mechanical strength - the half-fingered joints offer optimal balance between minimal CNC machining and significant strength, while full fingered lap joints provide maximum strength but require extensive machining.\r\n\r\nNote that I've 3D printed and tested these joints, although I haven't CNC machined any of them yet.\r\n\r\nKeep in mind that the STL files are for illustration purposes only - the arms themselves are basic and not intended for direct use. The bolt placement is also illustrative, as it may not provide optimal strength.