This paper deals with a new prototyping method called dot-matrix elect
rical discharge machining (EDM) with scanning motion. The machining pr
ocess by the dot-matrix method is similar to printing motion with a do
t-impact printer. This method can be applied not only to EDM but also
electrochemical machining and forming. A prototype of the machining un
it for the dot-matrix method has six feeding devices for thin wire ele
ctrodes. The electrodes of 300 mu m in diameter are arranged with the
pitches of 760 mu m. To obtain a smooth surface, a planetary motion in
the x-y-plane is added to the feeding of the machining unit in the z-
direction, the same area is machined repeatedly, or the machining unit
is moved with fine feed. By compensating for the wear of the electrod
e during the scanning EDM, various shapes with the accuracy of-microme
ters order can be obtained without a formed tool electrode. (C) 1997 E
lsevier Science Inc.