Enough to allow free movement within the head gate. line up part (f1) 1 from part (f2) already installed. 7. drill a hole with a 11/32 bit through the lower part (g), (fig. 7), part (f1) that moves, and part (g) on opposite side. use a 13/16 bit to enlarge the hole on milk stand / goat stand plans author:. Goat milking stand plans | building a new milkstand - the goat spot - goat forum.