FLXIBLE TOOLING FOR MANUFACTURING 3D PANELS
USING MULTI-POINT FORMING METHODLOGY
D.T. Pham1, S.Z. Su1, M.Z. Li2 , C.G. Liu2, F. Carrai3, F. Massabe4, A.M.Yan5, M. Vinay6
1 Manufacturing Engineering Centre, Cardiff University, Cardiff, United Kingdom
2 Dieless Forming Technology Development Centre, Jilin University, China
3 Kayser Italia S.r.l, Italy
4 Ingeniero Industrial, SENER Ingeniería y Sistemas, S.A, Spain
5 Open Engineering SA, Belgium
6 Centre de Recherche en Aéronautique ASBL, Belgium
KEYWORDS: Flexible tooling, Multi-point forming, Multi-point positioning.
ABSTRACT. This paper introduces a rapid and flexible tooling for manufacturing 3D panels using multi-
point forming (MPF) methodology. MPF technology employs adjustable element matrices and each ele-
ment in matrix can be controlled to adjust its coordinates for shaping a discrete 3D tooling surface. The
digitally adjustable tooling system includes dieless multi-point forming tooling and jig-less multi-point
positioning (MPP) tooling for automatically forming and flexibly assembly of 3D surface parts. Three
prototypes of the tooling are being developed within the EC-granted FP6 project DATAFORM. Compared
with traditional solid dies forming, hard jig assembly and fixed fixture fabrication, the cost-effective tool-
ing is for die-less forming and jigless assembly. The tooling system integrates the MPF/MPP techniques
with the CAD/CAE/CAT software to realize rapid fabrication of 3D panels. The paper introduces the
principle, mechanism and configuration of MPF/MPP tooling in details. Also, the paper gives some ex-
perimental results of 3D surface panels.
The need of flexible and reconfigurable tooling, which is fast adaptable, cost-effective and easy-
to-use, in manufacture procedures is increasing in the industry nowadays. Many scholars and
researchers from Europe, Asia and U.S.A have studied on new technologies of dieless forming
and jigless assembly as some disadvantages in traditional solid die forming and fixed jig assem-
bly. Reconfigure die forming technology by R. D. Webb & D. E. Hardt in 1991and multi-point
forming technology by Li M. et al., in 1999 have been proposed. Some experimental apparatuses
and machines have been developed  . However, there are some key technological problems
need to be solved for automatically forming large complex 3D panels.
Assembly of 3D panels in manufacturing fields plays an important role in modern industries such
as aeronautics, aerospace, shipbuilding and automobile making. However, there are some disad-
vantages in traditional hard jig fabrication and fixed fixture assembly, for example, longer
production preparation period, higher manufacturing cost, bigger tooling storage, worse labour
conditions and poorer panel quality. Many scholars and researchers from companies and univer-
sity in America and Europe have studied on novel technologies of flexible fixturing and jigless
assembly. Reconfigure assembly tooling technology by Henrik Kihlman in 2002 and jigless aero-
space manufacturing technology by Soe Naing et al., in 2000 have been proposed. Some experi-
mental apparatuses and commercial equipment with hydraulic cylinder or pneumatic actuator
have been made  . However, there are some key technological problems need to be solved
for rapidly and cost-effective jigless assembly 3D panels with novel electric actuators to meet of
new products in the growing market.
2 DIGITALIZED MULTI-POINT FORMING AND POSITIONING METHODS
Digitalize multi-point technique employs adjustable element group (EG), which can be
controlled serially or parallel by computer robotic system, to adjust its coordinates to configure
a discrete 3D tool surface.
Multi-point dieless forming tooling employs adjustable punch matrices without using the
traditional solid dies. Generally, there are two types of elements used in multi-point tooling,
i.e. the fixed element and the mobile element. The fixed element is adjusted to proper position
before forming and not adjusted during the whole forming process. The mobile element is
drove from up and down during the whole forming process. With the change of the relative
positions of elements during the forming process, deformation path and stress distribution of
formed parts can be changed, which affects the quality of formed panels. During the digital-
ized multi-point dieless forming and jigless positioning process, each of elements can be
controlled by computer control robotic system to adjust its coordinates to shape discrete 3D
2.1 MULTI-POINT PRESS FORMING
Multi-point press forming employs two sets of punch matrices with traditional press machine.
Using two types of elements above separately, the two typical forming methods are easily applied
into industrial production, i.e. fixed multi-point press forming method and mobile multi-point
press forming method, see Figures 1 and 2.
FIGURE 1. Fixed multi-point press forming method
FIGURE 2. Mobile multi-point press forming method
2.2 MULTI-POINT STRETCH FORMING
Multi-point stretch forming employs one set of punch matrix with traditional stretch ma-
chine. Fixed multi-point stretch forming and mobile multi-point stretch forming are typical
forming methods, see Figures 3 and 4.
FIGURE 3. Fixed multi-point stretch forming method
FIGURE 4. Mobile multi-point stretch forming method
2.3 MULTI-POINT JIGLESS POSITIONING
Multi-point jigless poisoning technique employs one set of loosely-packed actuator matrix
without using the traditional fixed fixtures or hard jigs. All of actuators in EG are fixed ele-
ments in fixed multi-point positioning. All of elements in EG are active mobile elements in
mobile multi-point positioning.
FIGURE 5. Fixed multi-point positioning tooling
FIGURE 6. Mobile multi-point positioning tooling
3 FLEXIBLE TOOLING MANUFACTURING SYSTEM
The flexible tooling manufacturing system consists of hardware of multi-point forming and
positioning tooling, robotic control unit, laser CMM and integrated software of
CAD/CAE/CAM/CAT, see Figure 7. The system is perfectly flexible system because high tech-
nologies of computer, FEM simulation and robotic control are applied to the whole
manufacturing process from surface modeling and numerical simulation to fabrication and meas-
FIGURE 7. Digitally flexible multi-point tooling manufacturing system
3.1 INIEGRATED CAD/CAE/CAT SOFTWARE PLATFORM
The integrated CAD software platform is to model the 3D panel product and output discrete
3D surface data according to the shape, multi-point tooling and material required. The CAE soft-
ware also predicts the final results and defects with the elastic-plastic FEM, see Figure 8.
FIGURE 8. CAD model of 3D panel and visual multi-point tooling
3.2 ROBOTIC CONTROL UNIT
Robotic control unit adjusts the upper and lower punch matrices in serial or parallel ad-
justing mode to shape tool surfaces according 3D data output by CAD/CAE software, see
Figures 9 and 10.
FIGURE 9. Serial adjusting mode
FIGURE 10. Parallel adjusting mode
3.3 CONFIGURATION OF MULTI-POINT POSITION TOOLING SYSTEM
Flexible multi-point positioning tooling prototype is a digitally adjustable positioning sys-
tem. The tooling with one set of loosely-packed electric actuator EG is used to hold/support
and clamp vertically or horizontally formed panels for subassembly. There are two kinds of
typical arrangement of actuator element groups, which are the regular array and the irregular
matrix. The types of modular units in regular array and irregular matrix are single-axis linear
electric actuators and multi-axes motion units with a single-axis linear electric actuator respec-
tively. The figure 11 shows a configuration of the multi-point positioning tooling with 22
above two types of modular units of electric actuator EG.
FIGURE 11. Configuration of the multi-point positioning tooling
4 MULTI-POINT PROTOYPE AND EXPERIMENTAL RESULTS
Based on the principle above, three prototypes of multi-point press forming and multi-point
positioning tooling are being designed and manufactured within the EC-granted DATAFORM
project for manufacturing aircraft panels. The figure 12 shows one of multiple punch group,
which has been fabricated for dieless multi-point stretch forming.
FIGURE 12. A punch group of multi-point tooling prototype
The flexible tooling manufacturing system has been applied to manufacture many 3D
panel products for novel vehicle and high-speed streamline train, skull implant, large sculpture,
modern architecture and aircraft, see Figure 13.
FIGURE 13. Formed specimens with multi-point press and stretch forming tooling
A flexible tooling of dieless multi-point forming and jigless multi-point positioning for manu-
facturing 3D aircraft panel has been developed within EC-granted DATAFORM project. Three
prototypes of the digitally adjustable tooling; multi-point press forming, multi-point stretch form-
ing and jigless multi-point positioning tooling, have been being fabricated within the
DATAFORM project. The dieless forming system will cut down so tremendous expense cost and
long time for manufacturing solid dies and improved the deformation condition and minimize
spring-back of 3D aircraft panels. The jigless positioning tooling is for flexibly assembly of 3D
formed panels. The tooling system will realize rapid and cost-effective fabrication of 3D aircraft
panels through flexible supporting, holding and clamping process.
The DATAFORM project is funded by the European Commission under FP6 in the area
of Aeronautics (contract No. 030877).
1. R. D. Webb & D. E. Hardt, (1991). A Transfer Function Description of Sheet Metal Forming for
Process Control, Journal of Engineering for Industry, No.113, pp.44-52.
2. Li M., Liu Y. & Su S. (1999). Multi-Point Forming: a Flexible Manufacturing Method for a 3-D Sur-
face Sheet，Journal of Materials Processing Technology, No. 87, pp.277-280.
3. Henrik Kihlman, (2002). Affordable Reconfigurable Assembly Tooling, Thesis of Linköping Univer-
sitet, ISBN: 91-7373-460-8, Linköping, Sweden.
4. Soe Naing, Graham Burley, Randolph Odi, et al. (2000). Design for tooling to enable jigless assembly-
an integrated methodology for jigless assembly. Society of Automotive Engineers, Inc. 109(1)