Robotic Stone Carving: From Canova's Studio to ABB Arms

Marble sculpture has always involved more hands than the one name on the plinth. Studios used assistants, measuring tools and copying methods long before anyone wrote a toolpath. Robotic stone carving is the latest version of that division of labour: a large robot arm with a spinning diamond tool cuts the rough shape out of the block, and a carver finishes the surface. This post goes from the pointing machines of 18th and 19th century studios to the robots of Carrara, a granite workshop in England that runs three ABB robots, and the open questions about cost, dust and skill.

Marble quarries cut into the Apuan Alps above Carrara, 2021. Photo: Ingo Mehling / Wikimedia Commons (CC BY-SA 4.0)

Pointing machines and the studio assistants

For centuries, getting a design from the model into the block took most of the labour. A sculptor modelled the figure in clay or wax, a plaster cast was taken, and assistants copied that plaster into stone point by point. The tool for this was the pointing machine, a frame of rods and joints with an adjustable needle. Its invention has been credited both to the French sculptor and medallist Nicolas-Marie Gatteaux and to the British sculptor John Bacon, and Antonio Canova later perfected it. Similar copying devices existed in Roman times, when workshops turned out copies of Greek statues.

A pointing machine set on a half carved stone lion in a sculptor's workshop. Photo: Reiner Flassig / Wikimedia Commons (CC BY-SA 2.0 DE)

The method, called indirect carving, made big studios possible. Three reference points on the model and three on the block let an assistant drill to the right depth at many points, then carve away the stone between them. The sculptor could fix the form in plaster, where mistakes were cheap, and leave most of the cutting to others. Canova's plasters, still kept at his museum in Possagno, still carry the small marks of this process. In the 20th century many sculptors turned to direct carving instead, and the pointing machine fell out of use.

Canova's plaster models in the Gipsoteca at Possagno. Photo: seier+seier / Wikimedia Commons (CC BY 2.0)

Machines came into the stone trade first for the heavy, repetitive cuts. Carrara has been quarried since Roman times, and more marble has come out of its more than 650 quarry sites than from any other place. Saws, and later computer-controlled milling machines, took over blocks, slabs and architectural pieces long before figures. A three-axis machine can cut a relief or a simple form but struggles with undercuts, the deep folds of drapery and the space between an arm and a body. Those shapes need a tool that can reach in from many directions, which is what a six-axis robot arm offers.

A CNC router with a carved piece on its bed at SITU Fabrication, 2022. Photo: Rhododendrites / Wikimedia Commons (CC BY-SA 4.0)

Robots in Carrara and a granite shop in England

Robotic carving is in the news this autumn. On 24 September 2026 Euronews reported from Carrara on Robotor and LITIX, whose robot carved a full-size statue of the Greek goddess Tyche from a single block of marble. A digital image becomes a 3D file, software generates the toolpaths and the robot does most of the carving before skilled workers refine it. Robotor's founder and chief executive Giacomo Massari has said the robot does about 99 percent of the work and that the last 1 percent, done by hand, makes the difference.

Inside an underground Carrara marble quarry, with an excavator at work. Photo: Vmenkov / Wikimedia Commons (CC BY-SA 3.0)

ABB robots already do this work in at least one British shop. In 2023 the trade magazine Stone Specialist described Planet Sculpture, a company started by Steve Murphy of Planet Granite near Coventry, with three ABB robots named Raphael, Michelangelo and Leonardo shaping stone in workshops on either side of a control room. The robots came from J Rotherham in Yorkshire, which went into administration in 2020, and the Murphys trained with Terzago Robotics in Italy. One of their first jobs was a larger than life Batman cut into a granite block.

An ABB IRB 6700 grinding a steel part in Teqram's EasyGrinder cell at Ancofer. Photo: ABB

Artists use these machines in different ways. The Italian artist Quayola calls his approach algorithmic sculpting and told Euronews he feels completely in control of the result. Others see the robot as a faster assistant. According to Robotor, its robots reproduced a statue that took Canova five years in 270 hours. The dust is another reason studios like the machines: carving marble releases fine dust that can cause silicosis, and a robot cell lets the carver stay outside the room while the roughing runs.

The artist Quayola, left, speaking with Billie Faircloth at Columbia GSAPP, 2016. Photo: GSAPPstudent / Wikimedia Commons (CC BY-SA 4.0)

Where stone carving robots go next

For engineers, a carving cell is a machining problem. A large arm such as ABB's IRB 6700 can carry a heavy spindle and already grinds steel parts in metal shops, so carving stone with it is a realistic possibility, but ABB has not announced a sculpture product. The toolpath itself comes from the 3D model. ABB's offline software lets engineers import that model, generate paths and check reach and collisions in RobotStudio before the first cut, as is already done for robot 3D printing.

An engineer runs a robot 3D print planned in ABB RobotStudio. Photo: ABB

Smaller studios may get a different kind of robot. A cobot such as the GoFa CRB 15000 cannot carry a big milling spindle, but it could hold a sanding or polishing tool for the long finishing passes that wear out wrists, while the carver works on the details. That is a possibility, not something ABB sells today. For homes, the nearest result is cheaper custom pieces: a scanned family pet or a portrait bust in marble that would once have needed months of skilled carving.

Lead-through teaching: moving an ABB GoFa arm by hand. Photo: ABB

Cost, skill and taste remain the open problems. A large robot with a spindle, water cooling, dust extraction and a scanner is a big investment, and Planet Sculpture's owners say they learned much of the programming as they went. The finish still needs carvers who can do the last 1 percent by hand, and some sculptors reject the method outright. "If Michelangelo saw the robots, he would tear out his hair," the sculptor Michele Monfroni told The New York Times. Massari's reply, given to Euronews, is that "you're not killing a job, you're just evolving that job."

Michelangelo's David, carved from Carrara marble, in the Galleria dell'Accademia, Florence. Photo: Dimitris Kamaras / Wikimedia Commons (CC BY 2.0)

Innovation

AI solutions for effortless ABB robot control.

Automation

Robotics

ceojohntran@chatwithrobot.net

+84905311611

© 2025. All rights reserved.

qtran1215@gmail.com