Magnetic Balljoint

thingiverse

Both ball and socket contain small magnets, organized in a uniform pattern. The socket has a limited number of "preferred" positions, defined by the pattern of the magnets. My implementation has about 20 positions. The key to the design is the magnet pattern, I chose to use an icosahedron (sphere-like shape that consists of 20 equilateral triangles). To increase resolution, I split up every single triangle into four sub-triangles. The centers of these triangles are the holes in the socket and ball. If you decide to build this, be aware that the threads are actually printed a little bit smaller than the 1/4 inch that they should be. I did this deliberately, don't trust my printer to print perfect threads under all these angles. Instead, I use a thread cutter to bring them to the correct diameter. The magnets are of the neodymium type and have a diameter of 6.3mm and a thickness of 3.2mm. Use a strong glue to glue them into their holders. To screw in the magnet holders, I use tweezers. Note: The file "ball_pattern.stl" is included as an illustration of the magnet positions, this file obviously should not be printed.