My son made a 3d printer that prints its own parts to make another one of it.
Pretty cool!
Carolyn
Im not good at programing and drawing on computer but im skilled at building myself and the seed releasing mechanism il make it from steel or glued plastic or carbon fiber.
Will probably need more releasing mechanisms for smaller seeds,intermediate size seeds and bigger seeds.
Even with the flight controller,il not mess around to buy one that needs complicated programming and tunning.
Instead il but the plug and play and safest to fly, NAZA flight controller with gps just like all the Dji drones have,(even their 20 000 dollars agricultural drone uses it).