This board illustrates the process of cutting of involutes Gear Teeth, by use of rack type cutter It consists of 3 white acrylic discs A, B, C. having pitch circle diameter 450 mm, 300 mm & 200 mm respectively. A gear tooth profile with module 25mm can be traced out on a piece of paper placed between disc and cutter. An affect of Interference and Undercutting on correct profile of gear tooth can be studied from the profiles traced.