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. This is
precisely what are you doing only in three dimensions. Where
connect 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
objects x, y, and z planes. In fact, it is best to indicate on a board
with a pencil those bisecting lines, and then line up the object to
that board 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
larger plane that has corresponding centerlines. On that board you
choose fix 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 you’ve
mounted the base and foot. Next you fashion a cross/tripod
that will rest on these three points without the tripod having to
penetrate the internal bounds of the rectangular solid (figure 6).

Once the cross is made and the tripod is situated, you make a
second board with all the bisecting lines and three points in
correspondence 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 other board.
Now you are ready to proceed.

You clamp the machinetta to your cross and place the cross’s
tripod 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 the material
from the block from all sides. Do not choose a single point and
then connect the dots. First, find the outer most points. In the
example 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
your 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,
you should 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
more checking 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.

Order# 37MAC Price $399.99
Plaster Foot on base
with x,y & z
coordinates labeled
Rectangular solid
with proper dimensions
Foot, base and board with
coordinated bisecting lines
Rectangular solid
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"
(roughing out)
Carved to within 1/4"
(Clean up)
Carved to within 1/32"