Because friction plays a large role in the operation of the wedge, it is difficult to determine its mechanical advantage. Let \(\ell\) be the length of the arm, and let \(p\) be the pitch of the screw...Because friction plays a large role in the operation of the wedge, it is difficult to determine its mechanical advantage. Let \(\ell\) be the length of the arm, and let \(p\) be the pitch of the screw (the distance between successive threads). Then one complete turn of the arm will move the end of the arm a distance \(2 \pi \ell\), and this will result in the load being moved a distance \(p\). The mechanical advantage of the jackscrew is then \(F_{R} / F_{E}\), or
