I bought a mobility fertilizer spreader with Raven fast close valve. I bought new Raven 660 controller, how do I calibrate urea without scales, I got 25 to semi load if urea, I calculated the spreader constant using the formula of gate height x chain width × distance of chain travel per one revolution of the encoder, entered the density. Entered the rates, but over 100 lbs to acre off.
Raven 660 controller & calibration
