УДК 621.941.2.06 AXIS DEFORMABLE FRONT CENTRE The paper dwells on the original construction of a front centre with axis deformable membrane. <...> The measuring of the membrane has been documented via the method of finite elements. <...> The axis deformation achieved considerably exceeds the range of depth of the central openings and the maximal tensions in the most dangerous sections are held under the permissible levels for constructional steel. <...> It has been experimentally proven that the radial stability of the proposed centre is practically identical to that with a hard front centre. <...> Keywords: lathes, front deformable centre, elastic deformation, stability, error of the basis. 1. <...> INTRODUCTION The he use of step shafts in the processes of lathing and grinding is one of the main tasks machine builders encount in their practice. <...> Several possibilities have been explored, and each one has its merits and disadvantages relative to misplacement, system stability and the complexity of technological equipment which reflects upon its cost. <...> The purpose of the paper is to propose as a solution an original construction of an axis-deformable front centre which will comply with the requirements for precision, stability and cost-effectiveness. <...> If it is to be processed, there will be an uneven addition with certain consequences. [2, 10] lathes is the cartridge with pre-processed journal and a back centre (fig. 1). <...> Apart from the undisputable drawback from a managerial and organisational perspective which requires additional procedures, this process is not good in that it also has the disadvantage from a technological standpoint, namely it doesn't permit for the principle of constant bases to be applied. <...> This results in errors in the relative positioning (radial and axial backlash) of the processed surfaces. <...> For example, if the radial displacement of the opening axis of the front centre is е, the lathing of a cross section at coordinate zi the radial able disadvantage, however, is in order to achieve automatically linear dimensions, set from the distant left point, the error of the basis is equal to the range of the depth of the centre opening. <...> It tends, however, to diminish the stability and precision in the radial direction - the error of the basement of diametrical dimensions is equal to the range between the centre of the cylinder and the leading opening. <...> OUR APPROACH As an alternative to the classical floating front centre is <...>