Turret Joint

thingiverse

Human: Note: After creating this system, I learned that it was basically designed in 1999 as explained in this patent by Se-Kyong Song, Dong-Soo Kwon, Wan Soo Kim. This assembly should actually be called the "Song Kwon Kim" or SKK joint in recognition of them. However, "turret-joint" more accurately captures what it is truly shaped like. Their patent has since lapsed, so you do not have to worry about patent infringement. This is a brand new kind of assembly which enables multiple components to come together at a single point with some flexibility in their angles. This allows us to create a strong joint for implementing irregular space frames or robots built from linear actuators. Note: My initial testing with moving actuators suggests that even though the joint works, it is quite "frictiony" when printed on the Fast setting on a Replicator 2---which makes sense because it is visibly striped and rough. However, to be an effective mechanical joint, we might have to increase the resolution of the print, or provide lubrication. I'm trying to test thoroughly before I take that step however. The current joint should be considered a initial design and a work in progress, not a finished product. You may want to watch my YouTube video explaining this. Or my video showing the large robot in action: This is a collection of parts which function together to form a construction system for building spaceframes, or moving robots, that allow some angular displacement in the members, without sacrificing strength or structural integrity. The fundamental innovation here is that the rotors can move, up to about 30 degrees, without losing any structural strength, because they are always pointed precisely at the center of the joint. Up to manufacturing tolerances, the joint does not introduce an "slop" or new degrees of freedom in the central point when bringing members together. This allows us to make trusses and spaceframes that are curved or wavy or in other ways deviate from purely equilateral triangles, without having to create a new joint for each angular displacement. This system includes several components. The basic parts are the ball, the lock, and rotors. The lock holds the rotor against the ball and ensures it is always pointed at the center of the joint (which is the center of the ball). Separate parts include separate caps that can be screwed to the locks to produce joints with different numbers of elements coming together. As presented here, the geometry is based on the Cuboctahedron, leading to the construction of Octet Trusses as patented by Buckminster Fuller in 1961. However, one could easily design various configurations. It features rotors specifically to mount the Firgelli L16 linear actuators and carbon tubes. These should be regarded as design starting points for mounting other components. The system is scalable. It can be scaled down to the point where your members start to collide with each other. This is an open-source hardware project intended to be a gift to the whole world. Do not attempt to patent it, which would be illegal and fraudulent. However, please manufacture it and earn money from it in any way that you can. I look forward to your comments and contributions. You may wish to join our team (you will be the second!) or promote our project, Public Invention (For All Humanity), PIFAH where many other emerging ideas are published. At my github repository you will find a drawing and a spreadsheet which explains some of the math on calculating the hole sizes and maximum angular displacement. https://github.com/PIFAH/turret-joint I utilized OpenSCAD to make it customizable by the Thingiverse community, although I miss the easy Fillet capabilities of Autodesk Fusion 360.