Incremental Sheet Forming: Panel Beaters to ABB Robots

Incremental sheet forming shapes a sheet of metal without a die. A round-tipped tool, usually 5 to 20 mm across, presses about a millimetre into a clamped sheet, traces one contour of the part, steps down and traces the next, until the whole shape is there. Robots now do this in production, and this summer a US Air Force C-17 flew again with a nose panel formed this way. This post goes from metal spinning and the English wheel to the first robot forming research and Ford's F3T, then to Machina Labs and the C-17 repair, and ends with where ABB robots fit and what still limits the process.

The newly formed nose panel during its first fit check on the C-17 at Wright-Patterson Air Force Base, 20 April 2026. Photo: Casey Tromp, U.S. Air Force via DVIDS (public domain)

How craftsmen shaped sheet metal without dies

Metal spinning is the oldest relative. The trade goes back to ancient Egypt, when soft metals were spun by human power on primitive lathes. A disc is clamped against a shaped block on a lathe and turned at high speed while the spinner pushes it over the block with a lever tool called a spoon. Water and steam power helped the craft in Europe and North America in the 19th century, and electric motors in the early 20th century let spinners work brass, copper, aluminium and even stainless steel. Spinning still makes cookware, brass instrument bells and rocket nose cones, all of them round.

Specimens of metal spinning, from the 1912 book Metal Spinning by C. Tuells and W. A. Painter. Photo: Internet Archive Book Images via Wikimedia Commons (no known restrictions)

Panel beaters handled the shapes that were not round. With hammers, dollies and the English wheel, a C-shaped frame that rolls a sheet between a flat upper wheel and a domed anvil wheel, a skilled worker stretches flat aluminium or steel into compound curves. The method survives in coachbuilding, car restoration, racing cars, prototypes and aircraft skins, wherever only a few panels are needed, and those panels are expensive because the work is skilled and slow. For mass production the wheel gives way to a stamping press, which makes a panel in seconds but needs its own set of dies for every model.

An English wheel with interchangeable anvil rollers, the hand tool for stretching sheet metal into compound curves. Photo: Glenn McKechnie / Wikimedia Commons (CC BY-SA 3.0)

Incremental sheet forming moved the panel beater's idea onto a machine. The sheet is clamped in a frame, and a round tool on a CNC machine or a robot arm pushes it down contour by contour, following a program. In single-point forming the tool works from one side, while double-sided forming uses a tool on each side so that features can point both ways. In 2005 Timo Schäfer and Rolf Dieter Schraft described incremental sheet metal forming by industrial robots in the Rapid Prototyping Journal. In 2013 Ford showed its Freeform Fabrication Technology, F3T, for prototype car parts, holding the sheet at its edges while stylus-like tools press on it from above and below.

A Deckel Maho DMU 50 eVolution CNC machining centre, the kind of milling machine often fitted with a round tool for incremental forming research. Photo: Glenn McKechnie / Wikimedia Commons (CC BY-SA 2.0)

Robot forming flies on a C-17

Machina Labs, founded in Los Angeles in 2019, has turned the idea into a production cell. Its RoboCraftsman uses two industrial robot arms on linear rails, one on each side of a rigid frame that holds the sheet. Following toolpaths taken from the CAD model, the arms form the sheet layer by layer, and force, torque and displacement sensors on each arm feed a closed control loop. The same arm then swaps its forming tool for a laser profiler to scan the part, and the cell can trim and heat treat it as well. Machina claims lead times more than ten times shorter and tooling savings that can exceed $1 million per part design.

Press 81, a large Schuler press in the Mercedes-Benz press shop in Bremen; every panel it stamps needs its own set of dies. Photo: Uhu2600 / Wikimedia Commons (CC BY-SA 4.0)

The Air Force has now flown such a part. On 4 March 2025, storms at Fort Worth Alliance Airport blew two private Bombardier Challenger jets into a C-17 of the 445th Airlift Wing, damaging its left nose panel, and Boeing found no vendor willing to build tooling for a single part. The Air Force Rapid Sustainment Office formed a new panel on a RoboCraftsman that Machina had deployed there, working with the University of Dayton Research Institute, and the aircraft flew again on 30 July 2026. The Air Force calls it the first incrementally formed part flown on one of its aircraft. On 8 October Machina's defense arm announced AS9100 aerospace quality certification.

Storm damage to the C-17's left nose panel, which no supplier would tool up to replace. Photo: U.S. Air Force courtesy image via DVIDS (public domain)

ABB has announced no incremental forming product or customer. One of its robots does list the process in a university lab: at the University of New Hampshire's John Olson Advanced Manufacturing Center, an ABB IRB 7600 on a 20-metre track has single-point incremental sheet forming among its applications, next to machine tending. ABB's newer large robots, the IRB 7710 that succeeds the IRB 7600 and the IRB 7720, carry up to 620 kg and are offered for high-accuracy contact work such as machining and friction stir welding, with path accuracy down to 0.6 mm at up to 1,600 mm/s. Machina says its cell is robot agnostic and picks robots by load capacity, forming speed and material, so a cell on ABB arms is possible, though none has been announced.

An ABB IRB 7710 or IRB 7720 large robot with a spindle for high-accuracy contact work such as friction stir welding. Photo: ABB

What comes next for robotic sheet forming

Two robots working one sheet have to move in step. ABB's MultiMove lets one controller run up to four robots, with their motions coordinated or independent, which is what a double-sided forming cell needs. Such a cell would be planned and tested in RobotStudio, ABB's offline programming and simulation tool, before any metal is bent. In factories the first targets are parts made in small numbers: spare panels for ageing aircraft, prototypes and short runs of car body parts. Machina says carmakers and custom builders can already change production-grade body panels without new tooling.

ABB robots in a MultiMove cell at Gerresheimer, where one controller runs several robots. Photo: ABB

Outside factories, the effects should show up first in restoration and custom work, the same places where the English wheel survived. A classic car owner who needs one replacement panel now pays for hours of skilled wheeling and hammering, and a forming cell that works from a digital model could make that panel without a die. Time matters as much as money. The Rapid Sustainment Office said the robot cut the C-17 repair from years to only a few months. Machina is also growing in defense work: it created a defense subsidiary, Machina Bellator, in July and won a qualification contract from Lockheed Martin for the JASSM program.

A panel beater repairing a damaged car body. Photo: Agbalagba / Wikimedia Commons (CC BY-SA 4.0)

Incremental forming is less accurate than stamping, springback distorts the part, and the process is hard to simulate, so toolpaths take time to work out. It is also slow. A press stamps a panel in seconds while a robot traces it contour by contour, which keeps the method to low volumes, as our post on press line stamping shows from the other side. Qualification is another hurdle, since Machina's chief executive Ed Mehr says qualifying a part from a new process for flight can take years. Shops that adopt the method will need people who understand both sheet metal and robot programming.

Engineers plan a cell layout on screen with a FlexPendant at hand, next to an ABB IRB 7710 or IRB 7720. Photo: ABB

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