Natural History Museum (Dippy)
In 2018, the Natural History Museum in London commenced a UK-wide tour of its famous Dippy (Diplodocus) the dinosaur skeleton, to mark the end of its 112-year display. They wanted to create exact replicas of its enormous skull to bring on the tour and to send to partner institutions across the UK.
Since the skull replicas would be used for educational purposes (both on the tour and in the partner institutions), they needed to be both visually accurate and safe for handling. Having skulls that could be handled would help people get a better feel for its different features and functions. In the end, the team decided to create 8 skull replicas: 2 for the tour, 5 for partner institutions, and 1 to be retained for research purposes.
The Challenge:
With complex and irregular features, (like dozens of thin, ‘rake-like’ teeth and a long, bone-dense neck), a detailed model of the skull would be needed, and a highly precise 3D Printing process that could accurately recreate it.
Since the skull was very large (about 610mm in length), and too complex to be produced as a multi-component assembly, a considerable build frame would be required.
And with the skulls set to be transported across the UK and handled by millions of people, they would need to be tough and durable.
The 2 skulls brought on tour were seen (and handled) by over two million people.
The Solution:
The Natural History Museum’s original skull was laser-scanned, generating a hi-res digital model. This captured the exact shape of the dinosaur skull down to the most minute detail.
The scan was then converted into a CAD file by the engineering team here at LPE, to be used for printing. This method of scanning the skull (as opposed to creating a mould) allowed the skull to be recreated with perfect fidelity and without ever being touched, eliminating any risk of damage to the original artefact.
Since the skull was both sizeable and highly intricate, it was printed in SLA (Stereolithography) on an iPro 8000 machine. The SLA process can produce finely detailed parts with excellent precision, and the iPro 8000 machine offers a large build frame of up to 650x750x500mm. The resin chosen was Xtreme; an ultra-tough, durable ABS simulant with functional properties. This meant the skull replicas could be handled without risk of damage. Xtreme also produces lightweight parts, which would enable easier transportation of the skulls.
With excellent repeatability, the iPro 8000 printed 8 exact replica skulls. The supports were removed and the skulls were cured in a UV oven to solidify them. They were then hand-finished by LPE’s in-house post-processing team. This involved manual surface-smoothing using sanding paper and dremels (small hand tools). The skulls were then spray-painted a light, semi-gloss black, matching the exact colour and aesthetic of the original skull. They were then packaged up and delivered to the museum.
Step-by-step process:
1) Original skull scanned
2) Scanned digital image converted to CAD file
3) 8 skull replicas printed as single pieces in SLA
4) Supports removed from prints
5) Skulls UV-cured
6) Skulls hand-finished
7) Skulls spray painted black
8) Skulls packaged up and shipped
Dippy skull by NHM_Imaging on Sketchfab
The Result:
- The 2 skulls brought on tour were seen (and handled) by over two million people. Having skulls that were handleable has not only enabled closer examination and study, it has also made the skulls accessible to the blind and visually impaired.
- The other 5 skulls are still on display at leading museums across the UK.
- The dippy skull retained by the Natural History Museum continues to support paleontological research and education.