Patent ID: 7113271

Claim:
The method of measuring the orientation angle of a rotational axis to a reference line comprising: a. at least one reference string aligned to said reference line, b. a collimated light source that is rotated about said rotational axis where a collimated light beam from said collimated light source is projected toward said at least one reference string, c. a portable base that is attached to said collimated light source where said portable base does not move parallel to said rotational axis, d. where said collimated light source is movable on said portable base substantially parallel to said rotational axis and said collimated light source movement on said portable base is measured relative to said portable base with a scale, e. the relative position between said collimated light source and said reference line is determined at a plurality of locations on said reference line by use of said scale, by use of said at least one reference string, and by use of said collimated light beam, and f. the distance between said locations is known, whereby said orientation angle of said rotational axis to said reference line is determined.