I have a few questions about spreader calibration. I have the 80# cub cadet model, and am wanting to calibrate it. I believe it is the same as the lesco models. I have read up on calibrating the spreaders with calibration boxes / pans to figure out the effective spread pattern. Then figure out the spread pattern divided by 1000, to get the length of run to spread 1000 sq. ft. Weigh the material, spread the length and then weigh the material again. This should give you how many lbs per 1000 sq ft correct? Also does your effective spray pattern change with the dialing up and down on the settings? Do most people calibrate for every product that they are spreading? Just trying to get some helpful info.