1. The problem statement, all variables and given/known data Calculate the DoF (mobility) of the following system: 2. Relevant equations M = 3(L-1) - 2J1 - J2 (where L = number of links, J1 is the number of full binary joints and J2 is the number of half joints. 3. The attempt at a solution I am very confident about there being 9 links, and 1 half-joint (the pin in the slot above the L link) but I am unsure about the number of full joints which I numbered here. I know from 1-7 should be correct, but I don't know about the joints on the slider. Should there only be two binary joints for each like I put there? Which is basically one ternary joint... 2 on the rigid link 'L' and on the link to which the slider is attached. And if I am correct I take it there is only 1 DoF then, which is the rotational of the circle attached to the top? Help would be appreciated here.