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the robot are compensated in a optimizing phase where paths are planned such that movements
from one point to another includes minimum amount of movement. This affects a path where
movements of the robot are minimized and relative inaccuracy between the points is reduced. The
other motivation is the surface quality required in the prototype manufacturing. In those products,
typically allowed tolerance is between 6... 10% of the dimensions of the work piece. So in a typical
medium size product dimension length of 500 mm, allowed tolerance is between 30...50 mm and
that is definitely under performance of the robot system.

4. TESTS IN THE FOUNDRIES
The methods have been tested in simulation and actual production and results are very good. Using
the optimization, the paths that was not able to run normally, could be run. The usability of the
optimization has been improved based on the comments from the users. Also the splitting of the
CAM paths and CAD models was tested with a success. The actual milling process is described in
figure 5. The system was built up and tested in two different robot systems: ABB IRB6400 with
S4C controller and KUKA KRC 150L110 with KRC2 controller. Also both electric and air pressure
spindles was tested. Both of the robot systems with different spindles and tools was working fine.

5. CONCLUSIONS

In this paper, we present methods for manufacturing variety sizes of sand moulds using robot.
Using the flexible control of the robot system, a cost-effective production of small series can be
achieved. The proposed method consists of three different phases: CAD/CAM, off-line
programming and actual milling. The whole system has been tested in actual foundry environment
with very promising results.
References

Bloomenthal M., Riesenfeld R., Cohen E., Fish R., (2000), An Approach to Rapid Manufacturing
with Custom Fixturing, IEEE Int. Conf. on Robotics and Automation, San Francisco, USA, pp. 212-
219.
Jager P. J., Broek J. J., Horvath I., Kooijman A., Smit A. (2001). An Effective Geometric and
Kinematical Analysis of Ruled Surface Feature Manufacturabihty for Rapid Prototypind. Proc. Of
DETC'01. ASME 2001 Eng. Technical Conference and Computers and Information in Engineering
Conference. Pittsbourg, PA, Sep. 9-12. 2001.

Sallinen M., Heikkila T., (2000), Flexible Workobject Localisation for CAD -Based Robotics,
Proceedings of SPIE Intelligent Robots and Computer Vision XIX: Algorithms, Techniques, and
Active Vision. Boston, USA, 7 - 8 Nov. 2000. USA. Vol. 4197 (2000), pp. 130 - 139

Sirvio M., Vainola J., Vapalahti S., Sallinen M. (2002), Automatic Line for Manufacturing
Prototype Castings and Billets in Environmentally Friendly Robotic Cell, Proceedings of the
International Conference on Machine Automation (ICMA2002), 11-13.9.2002, Tampere, Finland.

Veergeest J., Tangelder J., Horvath I., Kovacs Z., Kuczogi G., (1998), Machining large complex
shapes using a 7 DOF tool, IFIP SSM'98 Symposium, Chryslr Tech. Center, 9-11 Nov 1998.