A new OpenRC tractor tool is out, the fertilizer!! You'll need a micro motor ( http://www.banggood.com/N20-DC... ) I recommend more than 100rpm for this use. Moreover, you'll need some M3 screws and nuts. I connected it with the tractor ESC so it runs accordingly. In fact, in old tractors as this one, it used to work like this. Watch the fertilizer in action at http://makitpro.com/index.php/... Hope you like it! ;)