Three axis goniometer

For use with a precision saw for slicing through a microstructural sample, said saw having a saw blade which is rotatable but otherwise stationary during a sawing operation and having a support shaft which is rotatable about an X axis, an arm support generally perpendicular to said X axis and carried at one end on said support shaft and having a sample mount carried at its opposite end whereby pivoting of said arm support about said X axis will cause a sample to be moved into the path of said saw blade for sawing through said sample, the improvement comprising, in combination, an adapter arm adjustably mounted on said opposite end of said arm support and being pivotable about a Z axis which is generally parallel to said arm support, first locking means which releasably locks said adapter arm to said arm support in a selected pivoted position about said Z axis, a rotatable member carried on said adapter arm and rotatable about a Y axis which is generally perpendicular to said adapter arm, second locking means for releasably locking said rotatable member to said adapter arm in a selected rotatable position about said Y axis, and said sample mount being carried on said rotatable member in a fixed position relative thereto, whereby a sample carried on said sample mount can be positioned at precise angles for sawing through specific planes.