Michelangelo’s “David” Has Been Perfectly Cloned With 3D Printing

Michelangelo’s “David” is considered by many to be the apotheosis of sculptures. There are over 30 different replicas of the statue scattered across the world, but none of them are as faithful to the original as the 3D printed copy that will be revealed at Dubai’s Expo 2020.

A 1:1 replica of Michelangelo’s “David” will be unveiled on October 1^st at Expo 2020 Dubai. The 17ft x 6.5ft “David 2.0” is entirely 3D printed and will serve as the pièce de résistance inside the Theatre of Memory in the Italian Pavilion at Expo 2020. Portions of the sculpture have already been displayed to tantalize arts and culture enthusiasts from the world over, and whet the appetites of those curious to see just how far additive manufacturing has come.

Michelangelo was only 26 years old when he was commissioned to work on the massive, partially-finished block of marble destined to be the “David” we know today. The sculptor began work in September 1501 and it took until the summer of 1504 to finish his enduring masterpiece. The statue captures the Biblical David as he faces Goliath in a moment of poise, courage and grace—a theme that has resonated through the ages.

Creating David’s Digital Twin

Completing the digital twin of the legendary sculpture was a highly collaborative, interdisciplinary task. Academics, 3D printing experts and art restorers worked together with Hexagon Manufacturing Intelligence to aggregate over 100,000 high-quality scans of the sculpture for creating a high-fidelity digital twin. Given David’s Golaithan size and weight, attaining these scans was a cumbersome task and required a combination of laser and structured-light scanners: the Leica Absolute Tracker AT960 and AICON StereoScan Neo.

The Leica Absolute Tracker AT960 offers scanning in six degrees of freedom (6DoF) with a laser scanner that records over 210,000 points per second regardless of surface type. As a portable laser scanner, it allowed staff members to scan the more inaccessible portions of the statue with high accuracy across wider surface areas.

A Hexagon staff member uses the AT960 to scan David’s ears. The scanning alone took two workers more than 10 days to complete. Staff had to use scaffolds to hand-scan sections of the statue while being several feet high. (Image courtesy of Hexagon.)

The AICON StereoScan Neo is an industry-grade structured-light scanner that scans an object and then projects the scan back onto the object to ensure high precision. The device was mounted onto scalable stairs and necessitated an arduous process of trial and error to pinpoint the perfect distance for optimal scanning (80cm). The StereoScan was able to deliver accuracy across small areas, making it possible to replicate Michelangelo’s superlative attention to detail on David’s face and hands. The structured-light scanner was also instrumental in recording the combined effects of acid rain, extreme heat and cold, dust, pollution and other forms of damage accrued on the statue over five centuries.

An illustration of StereoScan’s structured light scanning. Fundamentally, this type of scanning involves projecting different patterns of light (usually as stripes or a matrix) onto an object. The light pattern will distort based on the shape of the object and a high-power camera is used to map the way the pattern has deformed, usually from two different angles. Finally, the different images are triangulated to map out all the contours and textures of the object. (Image courtesy of Hexagon.)

“Scanning the David presented a number of challenges,” said Cesare Cassani, Automation Technologies and Portable Systems Manager, Hexagon’s Manufacturing Intelligence division. “Not only was the scale enormous, but the time constraints were also tight, and we had to overcome a number of obstacles as we went along. Specific parts such as the inside of the hands, and underneath the bent arm, for example, proved particularly challenging.”

By coupling laser scanning and structured-light scanning, Hexagon was able to reproduce all aspects of the original David’s textures and contours for its digital twin. (Image courtesy of Hexagon.)

3D Printing David’s Twin

Once all 100,000 scans were collected, and the textures and blemishes were recorded, the digital twin was completed. The next step was 3D printing the physical twin. Given its stature, 3D printing David 2.0 had to be carried out in 14 portions and was printed out of a material known as Dimengel, which is a lightweight, recyclable acrylic resin. It took nearly 160 hours to print all sections of the statue. The Italia Expo 2020 team released a time-lapse video of the process which—like so many videos of additive manufacturing—was oddly satisfying to watch.

David’s head being 3D printed. (Image courtesy of Hexagon.)

While Dimengel proved to be environmentally friendly, durable and weight-efficient for 3D printing the statue, the material bears no resemblance to the grandeur and sophistication of marble. For the 3D replica to truly encapsulate the majesty of its original, it was coated with a paste comprised of resin and Carrara marble—the same type of marble that Michelangelo used for sculpting David in the 16^th century.

An art restorer applies a paste containing resin and Carrara marble. This type of marble has been used to create statues since antiquity. Other famous structures made from Carrara marble include the Pantheon and the Column of Marcus Aurelius. (Image courtesy of Hexagon.)

“We had to give it the appearance of Michelangelo’s David and then to characterize it, to render on the surface. Those cracks, fractures, stains, abrasions, the more or less smooth parts,” explained Nicola Salvioli, who served as head of the art restorers working on the project. “And thus, to give a soul to what is, in reality, a copy that has been transformed from the digital into physical matter. We are in no way comparing ourselves to Michelangelo—because that’s unthinkable—but there is a desire to make the statue as realistic as possible.”

Once all these final touches were applied, David 2.0 was assembled and air transported to Dubai for the upcoming Expo 2020. The statue weighs around 450kg plus an additional 100kg of the base—ten times less than the original, which weighs roughly five tons and was carved out of a solid block of Carrara marble.

A fully assembled David 2.0 being transported. (Image courtesy of Hexagon.)

A New Art Form

At its heart, works of art are not just decorations but declarations. They’re not just something to admire, but something to communicate with. They’re a message from the creator to the viewer. And so it is with David 2.0.

“We will send him as a messenger to the Expo in Dubai,” said Cecilie Hollberg, Director of Accademia Gallery, which houses David. “He will show us how to go on in this period, but the original will always stay here.”

Outside of astonishing attendees at Dubai’s Expo 2020, there are real-world applications of producing such a faithful twin. The high-fidelity scanning of David has uncovered the long-term effects of weather and pollution on sculptures. It has also uncovered details on the type of tools that were used by Michelangelo to carve David. These revelations help us gain a deeper understanding and appreciation of the arduous endeavor that led to the creation of Michelangelo’s David.

David 2.0 represents a culmination of the highest achievement in two very distinct forms of creative expression: sculpting and additive manufacturing. It’s proof that whether it’s 1501 or 2021, whether it’s chipping away at a massive block of marble or depositing layer after layer of gel, the human desire to create sublime works of art is as enduring as ever.