  The paper proposes a novel calibration approach for the Orthoglide-type
mechanisms based on observations of the manipulator leg parallelism during
mo-tions between the prespecified test postures. It employs a low-cost
measuring system composed of standard comparator indicators attached to the
universal magnetic stands. They are sequentially used for measuring the
deviation of the relevant leg location while the manipulator moves the TCP
along the Cartesian axes. Using the measured differences, the developed
algorithm estimates the joint offsets that are treated as the most essential
parameters to be adjusted. The sensitivity of the meas-urement methods and the
calibration accuracy are also studied. Experimental re-sults are presented that
demonstrate validity of the proposed calibration technique
