Tuesday, November 27, 2012
08 Joint Design Nº 20
I went way back into the archives and found some diagrams of knee joints. In this diagram, the difference between a deep socket and a shallow socket is illustrated. There is more range of motion with a shallow socket. Click on any image to enlarge it.
This diagram shows a single jointed knee with a shallow socket.
In order for the knee to bend at 90 degrees, the leg behind the ball would have to be cut deeper.
If stops are made in the knee joint, they can be designed on the outside of the form. The inside of all slip cast forms are smooth, and follow the mold walls, which define the outside of the forms.
This is a diagram of a more conventional single knee joint, with the legs cut at a 45 degree angle in the back, so the leg can bend at 90 degrees. The leg pivots around the center of the ball. In this diagram, the elastic is the green line, and the red line is the slot in the ball.
This is another diagram of a conventional single knee joint with a knee notch in the front, to keep the leg from rotating when standing. This was a problem I had with Carving Wax Test Doll.
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