Visitors to the Great Pagoda at Kew in Richmond, England may have marvelled at the impressive structure, which has stood in the gardens since 1761, though some may not have realized that some important decorative elements have been missing for centuries. The structure, commissioned during the reign of King George the III, was originally adorned with over 70 painted wooden dragons, which were at once majestic and terrifying. The dragons, which were removed for building maintenance in the 1780s, were never put back. That is, until now.
Thanks to a collaboration between the Historic Royal Palaces (HRP) and 3D Systems, 72 large-scale dragons, based on the original decorations, have been 3D printed and are being installed on the historic UNESCO World Heritage site building. The installation of the 3D printed dragons not only marks the completion of the HRP’s recent restoration effort for the Great Pagoda at Kew but also the most extensive use of additive manufacturing for a UNESCO project.
3D printing the intricate dragons was not quite as easy as hitting print on an STL file. Because the sculptures needed to be as authentic as possible and because many of the original wooden dragons were not well preserved—there are even rumours that the dragons were used as payment for royal gambling debts—3D Systems had to effectively reverse engineer the dragons to get a 3D printable model.
To achieve this, 3D Systems’ On Demand Manufacturing team used a FARO Design ScanArm to capture a 3D scan of a wood-carved dragon. This scan was then imported into 3D Systems’ Geomagic Design X reverse engineering software, which enabled the team to not only ensure accurate details but to integrate a hollow structure to cut back on weight. According to the team, it was able to reduce the weight of the 3D printed dragons by 60% compared to their wooden counterparts (weighing between 7 and 15 kg). The weight reduction offers the benefit of putting less stress on the historic Great Pagoda.
With the 3D model of the dragon prepped and scaled into a variety of sizes (between 1,150 mm to 1,850 mm in length), the On Demand Manufacturing team turned to its sPro 230 SLS printer for a durable, lightweight print. Each dragon was printed from DuraForm PA, a durable polyamide 12 nylon material whose properties suited the dragons’ look and function.
“We turned to 3D Systems to provide the rapid throughput, accurate details, and excellent finishing that was needed for this project,” said Craig Hatto, project director, Historic Royal Palaces. “The engineering skill of 3D Systems’ team, the opportunity to light-weight the dragon statues, and the material longevity of SLS 3D printing were key considerations for this project.”
Finally, the 72 3D printed dragons were precisely finished by a pair of 3D Systems’ artisans, who painstakingly hand-painted each detail. To put the scale of the effort into perspective, each dragon reportedly took about a day and half to paint.
“We so often see 3D printing technology applied to new innovations that when we get the chance to literally make history, it is quite exciting,” commented Phil Schultz, senior vice president and GM of Plastics and On Demand Manufacturing at 3D Systems. “In this collaboration with Historic Royal Palaces, we were able to bring new technology to bear on a historical landmark—restoring it to its former beauty and helping to ensure its future for generations to come.”
“It’s a testament to the capabilities and expertise of our On Demand Manufacturing team,” he added. “Our full suite of durable materials, 3D printing technologies, reverse engineering software and practical expertise allow us to create a custom solution no matter how unique the customer’s needs.”
Curious to see the restored Great Pagoda at Kew with its many 3D printed dragons? The UNESCO World Heritage site will reopen to the public this week, on July 13th.