A Cardanic Joint (or articulation)

Hello Everyone,
I’ve been working to create a cardanic joint. I need it for a Heavy Lift Drone design that I am working on. A cardanic joint is a type of universal joint where the main connection point of the joint can move in all three of the axes of motion, and also, the motion or reference point for all three of the axes is also the same point. A good example would be a ball and socket joint, except this joint that I made is a ball bearing joint for all rotations, there is no bushing bearing action. Whew! Of note, my design is also inherently scalable, if one wants more bearing capacity, the size of the joint can just be expanded using the Sketchup scale tool. My current joint (if the parts were good quality tool steel or stainless steel) will have a bearing capacity of 2000lbs. Of note the fully rotatable axis is ball bearing stabilized x2, meaning it is a radial-axial stabilized ball bearing joint or articulation, which means it is a thrust bearing. I made some of the parts less opaque so one can see how it works. I made some parts different colors so that as one inspects it, they can keep up with which part they are looking at. I need this joint for my Heavy Lift Drone design, but surprisingly, this joint is ideal for the hip and shoulder of a bi-pedal human mimicking balanced walking robot. I plan to try a robot leg-hip and shoulder-arm at some point with this joint. It has (for a robot) the tremendous advantage that it would not wear out very easily, and also being ball bearing, it will not have resistance to motion even if the robot leg is bearing all the weight of the robot.

I rendered it in KeyShot and that image is attached. I also think I can upload the Sketchup file too, I hope! Enjoy. Dr. Gray
v830 from 1st stuff Ball and Socket Joint v338.skp (2.4 MB)


Now this is some serious and precise modeling ! Well done. I misread your post title as “cardiac joint” and just had to look :rofl:

Thanks tuna1957, it is a fun project to create. I am always surprised that the engineers seem to have a name for everything. Apparently cardanic joints are used to make multiaxis CNC machines possible. I wanted to create a cardanic joint that was simple, strong, inexpensive, and scalable. I think mine could be made of plastic with 3D printer, if it wasn’t to bear too much force. Would allow normal folks to easily and inexpensively make simple but proper hips and shoulders for human mimicking robots. I am considering a stacked set of my cardanic joints to be the “vertebral column” of a human mimicking robot. I guess the stack would need to include that each cardanic joint is smaller than the joint below it, if one really wanted to mimic a human. This would allow a robot to have a feasible and inexpensive vertebral column and have subtle motions of the thorax (as humans do). The thorax is so heavy that small subtle motions of the thorax would allow bipedal balanced walking human mimicking robots to stay balanced. Would be a pretty cool image to render. Dr. Gray

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