|The pointing machine (La Machinetta di punta)
is a one to one proportion,
duplicating device. Which means
you can only copy an object in relation
to it’s own size, but not
enlarge or reduce. The best comparison that
can be made is to the
childhood game “connect the dots”. As
you connect the different
points in their sequence you come up with a picture.
precisely what are you doing only in three dimensions. Where
the dots has as an x and y axis describing the exact
location of each dot
in relation to the picture plane, the machinetta
method has an x, y and
z axis, from which you can locate each
point of an object in relation to
the space within a rectangular solid.
The first step is to locate the dimensional centers of each of the
x, y, and z planes. In fact, it is best to indicate on a board
pencil those bisecting lines, and then line up the object to
where the centers of the board and the object correspond.
In doing this
you are sure that the object is truly placed in the center
of the rectangular
solid. (figures 1-4)
Then you take the base and mounted foot and fix it to another
plane that has corresponding centerlines. On that board you
three points upon which the tripod/cross will rest,
from which you will
suspend your machinetta (figure 5). These
points should be outside the
dimensions of the rectangular solid,
however they should still be on the
board upon which
mounted the base and foot. Next you fashion a cross/tripod
that will rest on these three points without the tripod having to
the internal bounds of the rectangular solid (figure 6).
Once the cross is made and the tripod is situated, you make a
board with all the bisecting lines and three points in
with the first board. After that you mount your
rectangular solid with
its corresponding centerlines to the new
board. In the end you should
have two boards (figure 7). One
with a base and foot, indicating the centerlines
as well as the
three fixed points, the other with a rectangular solid
mounted to it,
with its centers and three points corresponding to the
Now you are ready to proceed.
You clamp the machinetta to your cross and place the cross’s
legs to their points. Then you proceed to remove material
from the rectangular
solid using the needle as the indicator of
your distance from finished
surface. At the beginning, you only
remove the material to within ¼”
from your finished surface
(figure 7). Keep in mind that one must remove
from the block from all sides. Do not choose a single point
then connect the dots. First, find the outer most points. In the
being shown, one would choose a point on the tip of
the big toe, a high
point of the Achilles tendon, the inner and
outer ankles, the points on
the width of the foot, and the high
points above the arch of the foot.
These are the reference points.
Basically you are roughing out. Continue until you have defined
rough geometric shapes. Such as the cylinder of the lower
leg, the wedge
of the foot. Inevitably getting closer and closer
to the finished surface.
After you have carved surfaces to within a quarter of an inch,
have a your original and a near copy of it, full of
dots that are related
in space (figure 8). Next you continue
carving within 1/32” from
your surface. With the sheer number
of dots it is impossible to keep track
of where you have already
passed. Therefore, you proceed to lightly circle
the dots you have
already brought down to within 1/32” (figure 9).
Once you have carved to within 1/32” all over, it is time to rasp
and sand down to your finished surface. This step requires no
or use of the machinetta, in the end you will have
two identical forms.
One filled with dot circles and bisecting
lines, the other a copy that
has been sanded and polished and is
flawless in its replication of form.
Plaster Foot on base
with x,y & z
with proper dimensions
Foot, base and board with
coordinated bisecting lines
with layout lines
corresponding to the foot
Measure and place
the tripod points
The cross and tripod
Your starting point
Carved to within 1/4"
Carved to within 1/4"
Carved to within 1/32"