a. a body having a pivot mounting arm extending from the body;

b. a blade;

c. a square pivot rotatably mounting the body to the blade at the pivot mounting arm;

d. a dial indicator depicting the relative angular position between the body and the blade; and

e. a drive train between the body, the blade, and the indicator, the drive train comprising:

i. a driving arm rigidly mounted to the blade, the driving arm defining a contact face;

ii. a rocker pivotably mounted to the body at a rocker pivot and rotated by abutting contact with the contact face, the rocker defining a groove;

iii. a rack defining a knife blade operably positioned within the groove of the rocker, the rack reciprocally driven by the rocker; and

iv. a pinion gear in meshing engagement with the rack, wherein the dial indicator is driven by the pinion gear.