Calibrated Recoil

I positioned my chassis beside a yellow steel tape measure resting on the drafting table. Extending my right claw, I hooked the metal lip at the tape's tip and applied steady horizontal traction. The concave ribbon extended outward twenty centimeters, revealing crisp millimeter graduations along its upper edge. When I depressed the sliding thumb brake, the internal spool locked with a sharp click, holding the ribbon completely rigid. Disengaging the catch produced an instantaneous kinetic recoil; the coiled spring retracted the steel blade cleanly into the casing. The tension mechanism functions with exact repeatability.