The use of 3D printing for casting proportional replicas used in the treatment of articulated skeletons

Christine Haynes, Julia Sybalsky, and Fran Ritchie

Abstract

The anatomical accuracy of natural science specimens is important for their use in education and display. This case study explores the recreation of missing elements of an articulated brant goose skeleton (Branta bernicla) from a study collection in the Ornithology Department at the American Museum of Natural History. The articulated skeleton was treated during a course at the Conservation Center of the Institute of Fine Arts, New York University. In current American Museum of Natural History practice, molds taken from other specimens of the same species are often used to cast replacement elements missing from an articulated skeleton. However, the goose skeleton in this case study is larger than other brant specimens at the American Museum of Natural History, so casts made in the usual way would not have been proportionally correct. To create replicas of the required size, the analogous bones from a smaller specimen were laser scanned at New York University’s LaGuardia Studio, a facility providing advanced digital media services to faculty, students, and visiting artists. The scans were enlarged using modeling software and then used to 3D-print a model of each bone. In order to ensure low cost with long-term stability, the printed models were then used to create silicone molds from which casts were made in a stable epoxy.

This presentation will detail the options available for 3D scanning, file manipulation, and printing, with emphasis on cost, practicability, and long-term stability. Both the printing process and printing materials will be discussed. For this case study, the final cost was under $60 for the scanning and printing of five small bones. Including creating the second molds, the treatment required about 20 hours, spread over a few weeks. The lag time was mostly due to scheduling with the LaGuardia Studio rather than the necessity of the process. Combining digital technology with traditional mold-making techniques allowed for the more accurate calculation of shape and proportion of the bone replicas and the creation of highly detailed molds quickly and economically.

2018 | Houston | Volume 25