At a summer Make Camp we wanted an inexpensive way for the campers to jig up bracelets and other paracord weavings. A clamp for each end was devised that straddled a yard stick for easy sizing. With a trapped screw and nut the ends are easily adjustable to the right point on the yardstick.
The design was developed in SolidWorks and the parts were printed on the Makerbot Replicator in ABS.