Shovel mechanics

[ddmckee54]

Your math is a little off. 1 cubic yard IS 36"x36"x36", but 1/2 of a cubic yard is 18"x36"x36". 18"x18"x18" would be 1/8 of a cubic yard.

1 cubic yard is 46,656 cubic inches, so 1/2 of a cubic yard is 23,328 cubic inches. This works out to a cube about 28.573" on each side.

At the scales you listed:
1/12 scale=2.38" (Close enough to 2-3/8")
1/14 scale=2.04" (Close enough to 2")
1/16 scale=1.78" (1-25/32" would be the closest fraction, 1-3/4" would be close enough for government work)