Star Tech Journal

october 1994
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CD
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....
THE CARE
&
FEE DING
OF BILL TRANSPORTS
Leo Tarlton
State Sales & Service
Baltimore, Maryland
LUBRICANfS
MAGNETICS
Let's talk about oil. Very useful
stuff, in the right place. The right
place is where two metal parts
rub against each other. I can't
think of any place in any modern
transport where metal rubs
against metal. It's always metal
rubbing against nylon. Transports
are designed this way on purpose.
There is a magnetic head in ev-
ery modern transport. This is a
wonderful coincidence since
United States currency is printed
with magnetic ink. As the bill
passes over the head, an electri-
cal signal is generated. This sig-
nal is used by a microprocessor
that decides whether the bill is
genuine. The bill must be pressed
firmly and uniformly against the
mag head.
Nylon is a naturally slippery ma-
terial. As used in transports, no
lubrication is necessary. Some
petroleum products ( oil) can
cause nylon to swell. If a nylon
roller is turning on a metal shaft,
and the nylon expands at the
junction, the roller will bind on
the shaft. This will cause the mo-
tor speed to fluctuate.
As the bill must move through
the transport at a precise speed
to be accepted, friction and me-
chanical binds are to be avoided.
Don't oil your transport. If you
have a squeak or squeal, you can
use a Teflon based spray. Before
you use anything, test it on a ny-
lon part before using it on your
transport. Oil will also attract and
hold dust and dirt, which will
cause friction and, when embed-
ded into the nylon rollers, will
score the metal shafts.
If there is a residue of sugar syrup
coating the mag head, the bill
can't get close enough. This prob-
lem is u~ually confined to Ardac
transports used in soda machines.
The mag head can be cleaned
with alcohol and a soft, clean
cloth or paper towel.
It is important that the gap in the
mag head be exactly perpendicu-
lar to the bill. Most transports
have adjustments to allow for
this.
Be careful that you do not disturb
these adjustments while trying to
get to the mag head. You might
cut a piece of plain paper to the
shape of a bill, pour a little alco-
hol onto the paper, and insert the
paper as you would a bill, letting
the transport take the paper in
and then reject it several times.
Follow with several pieces of dry
paper to remove any residue that
has been dissolved into the alco-
hol.
THE GAP
Since we've mentioned the gap,
let's talk about it. It is like a ditch
across the mag head, but it is so
narrow it is difficult to see. If any
of the metal is disturbed, it may
bridge the gap, and the mag head
is disabled. Do not let the surface
of the head touch anything hard.
Before the heads leave the fac-
tory, they are polished with 1000
grit emery paper and SW oil. If
your gap has very slight damage,
you may use this procedure to
repair it. Never insert a knife or
other metal object into the bill
slot, as this will damage the gap.
Long live your transport!
STARA'IECH
JOURNAL