Suppose I have a 3 link(1 dimensional) chain in which all the joints are revolutes, the axis of first revolute joint is along Z-axis(global) and axis of second joint is along X-axis(global). The first link is along X-axis(global) and second link is along Z-axis(global).
Now in order to use DH representation I introduced a local frame for link 1 at joint 1(z axis along Z and x axis along X) and another frame at joint 2.Here z-axis is along axis of rotation(global X) and here I am clueless how to determine x-axis for joint 2 because the two z axis are intersecting.(standard procedure is to find common normal between two z axis)
Thanks for your time.