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Building on previous and current work, this research utilizes the Single Point Incremental

Forming (SPIF) process to produce mass customized, double-curved (both positive

and negative Gaussian curvature), three-dimensional forms from sheet metal. These

forms are produced at a scale that suggests their use as cladding elements in a building

envelope. This, combined with the relative speed and efficiency of production and the

variability of resultant geometries, allows for speculation on the production of high per-

formance façade systems directly from digital models.

ROBOTIC INCREMENTAL SHEET METAL FORMING

Ammar Kalo University of Michigan

Michael Jake Newsum University of Michigan

Forming Variations: Geometry investigations looking into the viability of forming dual curvature, variable curvature, multi-directional curvature, and/or multi-axis valleys (Kalo and Newsum 2013).

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72RESEARCH PROJECTS ACADIA 2014 DESIGN AGENCY

This project demonstrates a number of proof of concept studies for

single point incremental forming as a viable technique to produce

highly variable, double curved panels in sheet materials, without the

requirement of expensive forming dies (Figure 1). The project also

provides a model for the development of a materially informed pro-

duction process, integrating design and fabrication into a stream-

lined production methodology.

Single point incremental forming is a process whereby a sheet of

metal is incrementally deformed at local points to achieve an overall

geometry (Figure 2). Typically, the stock is formed using a hemispher-

ical tool that can be attached to a robotic arm or a CNC machine.

The tool moves along a pre-programmed toolpath, as it gradually

steps down into the stock, until forming is complete (Bambach et al.

2009) (Figure 3). Several materials were tested to find the limitations

of the forming process and viability. The sampling of sheet metals

included cold rolled steel, aluminum, copper and brass (Figure 4).

Cold rolled steel was used in most of the forming tests because

of its high ductility and strength, which allowed for forming deeper

parts (Figure 5). Once trimmed from the rest of the stock, the formed

geometry would often deform into a new relaxed shape. This re-

lease of internal forces is called springback. The deeper a panel is

formed, the more it would become rigid and resist this deformation

(Kreimeier et al. 2011). Several design strategies, most prominently

the use of performative textures, were utilized to stabilize the com-

ponents pre-trimming (Kalo and Newsum 2014).

Since this investigation seeks to build on previous research on

incremental sheet forming, it addresses questions which are es-

sential to its applicability at an architectural scale, notably the ability

to aggregate multiple panels into a performative system. Various

strategies were explored for connecting formed panels into a larger

SPIF: A diagram showing the setup of a robotic single point incremental forming (SPIF) work cell (Kalo and Newsum 2013).

2 Toolpath: A parametric toolpathing script was developed to guide the robotic arm to form the desired geometry (Kalo and Newsum 2013).

3

Materials: Several materials including steel, aluminum, brass, and copper were tested for formability (Kalo and Newsum 2013).

4 Kalo, Ammar and Michael Jake Newsum (2013) Forming Slopes. Ann Arbor, Michigan: Realized

5

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aggregation. One technique overlapped the valleys and peaks

of doubly curved surfaces and then tack welded the surfaces

together to create a self-structured thickened porous skin condi-

tion (Kalo et al. 2014) (Figure 6).

Similar to bead rolling, adding ribs serves to locally corrugate the

sheet metal, where the geometry is the shallowest, to prevent it

from deforming. The ribs not only function as a performative part

of the process but also have a unique aesthetic quality. In addition,

the ribs could drive a global panel connection strategy. These ribs

were then used as identification points at the edges of panels to

align the aggregation (Figure 7). Geometries were also developed

that shared the same edge perimeter geometry. This allowed for

varying shapes to be formed within this boundary that could be

connected to one another as a continuous aggregation.

Kalo, Ammar and Michael Jake Newsum (2013) Porous Aggregation. Ann Arbor, Michigan: Realized6

KALO, NEWSUM ROBOTIC INCREMENTAL SHEET METAL FORMING

REFERENCESKalo, Ammar, Michael Jake Newsum. 2014. “An Investigation of Robotic Incremental Sheet Metal Forming as a Method for Prototyping Parametric Architectural Skins.” In Robotic Fabrication in Architecture, Art and Design 2014, edited by Wes McGee and Monica Ponce de Leon, 33-49. Switzerland: Springer International Publishing.

Kalo, Ammar, Michael Jake Newsum, and Wes McGee. 2014 “Performing: exploring incremental sheet metal forming methods for generating low-cost, highly customized components.” In Fabricate: Negotiating Design and Making, edited by Fabio Gramazio, Matthias Kohler and Silke Langenberg, 166-173. Zurich: gta Verlag.

Kreimeier, Dieter, Bolko Buff, Christian Magnus, Volker Smukala, and Junhong Zhu. 2011. “Robot-Based Incremental Sheet Metal Forming – Increasing the Geometrical Accuracy of Complex Parts.” Key Engineering Materials 473: 853-860.

Markus Bambach, Babak Taleb Araghi, and Gerhard Hirt. 2009. “Strategies to Improve the Geometric Accuracy in Asymmetric Single Point Incremental Forming” Production Engineering 3(2): 145–56.

74RESEARCH PROJECTS ACADIA 2014 DESIGN AGENCY

Kalo, Ammar and Michael Jake Newsum (2013) Performative Ribs. Ann Arbor, Michigan: Realized7

IMAGE CREDITS Figure 1. Kalo, Ammar and Michael Jake Newsum (2013) Forming Variations. Ann Arbor, Michigan: Realized

Figure 2. Kalo, Ammar and Michael Jake Newsum (2013) SPIF. Ann Arbor, Michigan: Realized

Figure 3. Kalo, Ammar and Michael Jake Newsum (2013) Toolpath. Ann Arbor, Michigan: Realized

Figure 4. Kalo, Ammar and Michael Jake Newsum (2013) Materials. Ann Arbor, Michigan: Realized

Figure 5. Kalo, Ammar and Michael Jake Newsum (2013) Forming Slopes. Ann Arbor, Michigan: Realized

Figure 6. Kalo, Ammar and Michael Jake Newsum (2013) Porous Aggregation. Ann Arbor, Michigan: Realized

Figure 7. Kalo, Ammar and Michael Jake Newsum (2013) Performative Ribs. Ann Arbor, Michigan: Realized

AMMAR KALO is currently the Director of CAAD Labs in the Department of Architecture, Art, and Design at the American University of Sharjah. He recently received a Master of Science in Architecture with concentrations in Material Systems and Digital Technologies at the Taubman College of Architecture and Urban Planning, University of Michigan. In 2014 he received the Kuka Young Potential Award at the Rob|Arch 2014 conference. Prior to graduate school, Ammar has gained experience working on international projects of various scales and typologies.

MICHAEL JAKE NEWSUM is the Robotics Lab Coordinator at the Southern California Institute of Architecture where he works with students and faculty on research projects that investigate the role of robotics in architecture and design. His work currently focuses on developing robotic design platforms that rethink the interactions between man and machine. He holds a Master of Science in Architecture with a concentration in Digital Technologies from the Taubman College of Architecture and Urban Planning, University of Michigan. He is also the recipient of the Kuka Young Potential Award at Rob|Arch 2014.