In this paper three groove semi kinematic mounting has been designed and analyzed its the stability in micro milling operational conditions, employed in a specific modular reconfigurable micro factory test bed developed at authors group. While various kinds of kinematic couplings, which are popular for their high repeatability and interchangeability, are considered for the modular machine design, Gothic arch and Maxwell coupling designs were compared. In this evaluation process, first the maximum preload, which can resist the induced contact stresses, is determined. Then the static stiffness matrices are evaluated for each case and compared as a measure of their relative stability. Maxwell coupling which was found to be best was adopted for the machine stage and experiments were performed to know the coupling stability with varying load.