Patent attributes
A coordinate positioning machine includes a drive frame and a metrology frame. The drive frame includes a drive arrangement for moving a structure around a working volume of the machine. The metrology frame includes a metrology arrangement for measuring the position of the structure within the working volume. The metrology arrangement is a hexapod metrology arrangement and the drive arrangement is a non-hexapod drive arrangement. The metrology frame has a coefficient of thermal expansion that is lower than that of the drive frame. The drive frame is coupled to the metrology frame via a coupling arrangement which prevents at least some distortion associated with any extra thermal expansion and contraction of the drive frame from being transferred to the metrology frame. The drive arrangement moves the structure around the working volume, and the metrology arrangement measures the position of the structure within the working volume.
