I am in the process of building a large rose trellis and needed an easier way of measuring footage for the scroll work than a string. Also knocked out a set of calipers to do the jig for a 4-1 scroll.
Scroll measuring wheel is 3 1/8" dia. by 1/8" thick. It doesn't really matter that much on size, you simply count the revolutions as you trace the pattern, then go straight and check with a tape measure. Body is made from two pieces of 1/8" flat bar with a 3/16 bolt welded in the middle and a walnut handle turned out on the metal lathe. Kinda crude, but I needed something in a hurry. Calipers were forged from 1018 with thumb screw to lock them in place.