ROBOTMAK3RS Blog

This NXT Peg Sorter will sort long black NXT pegs from long gray pegs, into two separate bins. A conveyor feeds pegs down in a chute, then the light sensor is used to see the color of the peg as it is sliding down the chute, then a hitting arm hits the black pegs to the side while allowing gray pegs to fall straight down into the other side. Here is a video of the machine in action: There are simpler and more reliable ways to sort pegs, but with this project I wanted to do something similar to the way some modern high speed mechanical sorters work in factories. In some of these machines, the items are thrown quickly past a gap in the conveyor belt, where an optical sensor looks for rejects, and then air jets are used to knock the rejected items down through the gap into a reject bin, while the good items continue past the gap to the other side. The challenges are to quickly detect a reject and then to get the right timing between seeing the reject and pushing it out of the fast movin...