Optical measurements with coordinate measurement machines equipped with optical sensors, and video measurement machines, are clearly increasing in industry. Accurately manufactured two-dimensional standards, with a precision typically between 0.05 μn and 5 μn, are used to check and calibrate these measuring machines. In order to start a calibration service for two-dimensional standards, a new calibration machine is currently under development at the Centre for Metrology and Accreditation (MIKES). In this paper we describe the mechanical design, properties and present a detailed uncertainty analysis of position measurement. By modeling and compensating mechanical error sources the required standard uncertainty level of 50 nm is achievable.