Topcon machine control technology and the SGS grading system allow an operator to complete a grade—forms can be set directly on it, reducing labor costs by more than 50%. Using the curb as a reference, the excavator moves along the road with the blade grading behind the curb without damaging utilities or curb. The Topcon controls the blade to within 1/4 in. of the desired grade, and no surveying is required. Sidewalk Grading Systems. 253-720-7756.