The equations connecting the horizontal and vertical movements of the grating mill with its geometric and operating parameters, in particular, with the value of the rotation angle of the drive eccentric, depending on time, are presented. The numerical solution of these equations allows us to determine the dependence of the horizontal and vertical displacements on the angle of rotation of the drive eccentric and on time. The approximation of numerical values makes it possible to establish analytical dependences of displacements on time in the form of polynomials, the differentiation of which makes it possible to find the velocities and accelerations of the lattice mill.