A data archiving system includes an archiving label including a label tag and a memory device carried by the label tag and a reading device adapted to retrieve repair information from the memory device. The rails have a slide fit with respect to the channel members. A display of the textual lists are centered around a current central display point, the current central display point corresponding to a point of the flight plan or a segment of the flight plan. The second constant current circuit 4 is also configured to serve as an activation circuit for the first constant current circuit 3a. Dental articulators and components of dental models as described herein use a positioning key to encode positional information for components of the dental model, andor a reference grid on mounting surfaces to enforce local accuracy of fabricated parts against a fixed reference array.