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 |
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Plaster Foot on base
with x,y & z
coordinates labeled |
Rectangular solid
with proper dimensions |
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Foot, base and board with
coordinated bisecting lines |
Rectangular solid
with layout lines
corresponding to the foot |
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Measure and place
the tripod points |
The cross and tripod |
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Your starting point |
Carved to within 1/4"
(roughing out) |
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Carved to within 1/4"
(Clean up) |
Carved to within 1/32" |
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Completed! |
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