The article contains the calculation of the tables necessary for the construction of helical surfaces z=aφ+f(r)z=aφ+f(r), which are encountered in the theory of the spiral separator. (See the work of M. I. Akimoff, "Motion of a heavy point on a helix located on a frosted surface" in the Annals of the Mining Institute in Leningrad, Vol. 10, Issue 1 (1936), pp. 11 and 21, Vol. 12, Issue 3 (1939), pp. 4, 5, 38 and 39. See also the article by V. A. Egonnoff, "On the theory of the spiral separator" in the same scientific publications, Vol. 10, Issue 1, pp. 23–30.)

The theory of the spiral separator is based on the study of the motion of a heavy point along a rough helical surface. The article integrates the differential equations of motion of a heavy point along a helical line on a rough surface having a curvilinear generatrix. As Prof. M. I. Akimov points out, this surface can be used for the construction of sorting machines. The motion of a heavy point along this surface occurs with a vertical velocity independent of the helical line of motion.