The most important distributing construction of small plot seed-drills, fertiliser dispensers is the cone dispenser. The cone dispenser can operate based on simple gravity or with Oyjord-type cone-cell or Hege-type cone-belt structure. The unevenness of spreading of each type is significantly influenced by the feeding roll above the cone and the misalignment of the cone dispenser. On designing, preparing and setting I realised that this job could be done much faster and more precisely if there would be model for testing the misalignment of the cone dispenser. In my article I will provide information about the essence of the mathematical model and its derivations. For the calculations I prepared a chart program in Microsoft Excel. In order to test the computed model I made experimental examinations. I put together a test bench for the measurements. I revealed that the mathematical model describes the unevenness of spreading caused by misalignment. In addition, I discovered that even a misalignment of 0.25-0.5 mm can be pointed out by measurements and is in proportion to the variety factor determined theoretically.