Investigation of the Dynamic State of Adjustable Milling Heads

The problem of improvements in machining large dimension flat surfaces of width 400 mm and closed ones, which are under the presence of engaging step on the sides, of unfinished workpieces productivity is considered. It is proposed to use milling heads with adjusting the milling width for the mentioned surfaces machining. A variant of the mill design has been developed, where the spindle block containing two face mills with intersecting cutter trajectories can be rotated by an angle in the range of 0°–360°. The dynamic characteristics studies into dedicated CMH with adjusting the milling width have been conducted. It has been established based on the three-mass dynamic model of the mill that rigidity changes in the feed plane even by 10% leads to a change in the main semi-axis of the ellipse of the movement trajectory along the y_i axis, while the change in the second axis can be considered as insignificant (up to 3%). It has been established that the proper selection of the mills’ system resulting rigidity can achieve tool operation stability and accuracy in size and geometry of the workpiece surface based on the study of the design of dynamic characteristics.