I have uploaded a PDF of a 1/8" per FT shrink rule with an explanation for its use to the downloads section. I am making a pattern for a T-Slotted slide for my lathe that I hope to get cast at one of the areas small iron foundries. I'm in no physical shape to be a sand crab so I can't see laying out the $s for a tool I will rarely use. If other sizes are needed, let me know as it is pretty easy to do.