Now we need to mount the air system
to the back of the chest cavity. I
used a small piece of 1/4" board to
mount all this on and screwed it to
the frame. Since you have already
assembled your air trigger, mount
this on the top left of your
assembly plate as shown in this
picture. You will notice that we
are using 2 different valves here.
Basically the only reason I use the
little needle valves at all is
because I have to couple these to
the small 1/4" air line going to
the bicycle pump and these enable
me to do so for a low price and
very accurate trimming of the air
pressure. However, when I can use
the 3/8" fittings as shown going to
the arms and arm bleed off I do. It
is just faster to work with and the
trim ability is accurate enough for
this application.
You should be able to duplicate the
assembly above using the materials
list from the previous pages. The
3/8" air line is clamped to the
trigger output, then to a slip
airline fitting that is threaded
into a T that will go off to both
the head and arms. For the line
going to the arms the air then goes
through a all thread fitting, into
a trim valve and into a 90 degree
elbow to another all thread fitting
and into another T. This T as you
can see splits off for the bleed
off and on to the junction at the
top of the shoulders where we split
off with a 3/8" male T to bring the
air into the arm rams. The line
that goes on to the head cylinder at the
first T goes into a male slip
fitting into a 1 1/2" long piece of
3/8" air line that is then slipped
over the thread section of one end
of the needle valve and clamped
directly to the threads. Don't
worry, this connection is more than
adequate, as the connection seems
to be air tight and this section of
air line does not sit under the 95
lbs of pressure at all times. The
only time it is subject to pressure
is under firing. Then the other end
of the needle valve is fitted with
a 1 1/2" section of 1/4" brass tube
that we clamp the end of our bike
pump line to. Between this
connection and the base of the bike
pump we cut the line in half and
insert a 1/4" male slip T inline
that we come off of with a 1 1/2"
section of 1/4" clear tubing that
is clamped then to the 1/4" brass
tube fitted to the bleed off valve.
Now you can adjust the head and
arms independently so you have
exactly the right balance of
pressure for both types of air rams
being used.
