Isostatic positionning on a lathe, and kinematic diagram:
<ul><li>chuck with "hard" jaws and stop (top);</li>
<li>chuck with "soft" (machined) jaws and stop (middle);</li>
<li>special mounting with planar joint and a centering (bottom).</li></ul>
All are equivalent to a revolute joint.
<a href="//commons.wikimedia.org/wiki/User:Cdang" title="User:Cdang">Cdang</a>
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