Home made broadhead alignment jig?

[Bowmania]

Get a shoe box
and take the cover off. Cut a V in each end of the top edges of the box so that an arrow will rest in the V's (parallel to the shoes that
are not in the box). Place the arrow to be tested in the V's and get a piece of paper that is a little higher than the height of the
box. Now place that piece of paper parallel to the end of the box so the arrow points at the paper and draw a dot on the paper where
the arrow points. Point the arrow at the dot and rotate the arrow. Any point that's true will point at the
point throughout the rotation. An arrow that's untrue will rotate around the point.