From: klf@druwa.ATT.COM (FranklinKL)
Newsgroups: rec.motorcycles
Subject: Wing World vest article
Keywords: Some data
Date: 15 Oct 92 18:36:24 GMT
Distribution: rec

In a recent posting, John asks:

>I can't aquire a copy of Wing World by any efficient means.  I would
>be most stupendously grateful if you could post a brief summary of
>the crucial information in the article.  (Use blah gauge wire, wire
>a thermostat like this, calculate the power drain like this, etc.)
>It would appear that lots of other people could use the info too.
> 
>Thanks!
> 
>-
>-John H. Osborn

The builder first determined how much current the vest could draw
by consulting the specifications for his bike.  He then took an existing
fabric vest and roughed out a pattern for laying out the wires on the
vest.  He then calculated the total length of the wire in the pattern
and, using standard wire tables, which give resistance for various
gauges of wire, he selected the gauge of wire that would allow that amount
of current to be drawn.  In his case, teflon coated 30 gauge wire was used.

The formula goes like this:

Amount of current vest is allowed to draw = I

Voltage source which will provide the feed = E  (The author used a combination
of his bikes spec sheets and measurements to come up with this voltage.
He used a number closer to the highest voltage that the bikes charging
system would produce to provide some margin.)

Total resistance of wiring in vest = R

R is calculated from the formula R = E/I

Once a value for R is determined, the wire tables should be consulted to
determine an appropriate gauge of wire.  The tables usually show the
wire resistance in Ohms/1000 ft. and/or in feet/Ohm.  Bearing in mind that
the wire should be fairly flexible, yet not so tiny as to be too fragile,
and knowing the approximate length of the wire pattern, a wire size
can be arrived at.  Note that some tuning is possible by modifying the
wire positioning pattern to lengthen or shorten it.

The approximate wattage of the vest can be calculated as follows:

Wattage = E*I

This is useful in that it is the indicator of the heat producing
capabilities of the vest.  Standard formulas can be used to convert
watts into BTUs, calories, etc.

The selected wire was laid out on the vest and secured with tape.  The
result was then covered with a material which I believe is called 
"Stitch Witch".  It is a material that when placed between two
pieces of fabric and ironed, bonds the two pieces together.  He claimed
it was readily available in fabric stores.  Over this bonding material
was placed a fabric covering and the pieces were ironed, bonding them
together and locking the wires in place.  Prior to the bonding step,
the 30 gauge wire was soldered to a length of 2 conductor lamp cord.
The joint was encapsulated within the vest.

The author cautioned the reader to test out the vest prior to encapsulating
the wires, which seems a sensible precaution.  The free end of the lamp
cord can be connected to the connector of your choice.  It is important
to use a GOOD grade of wire with a good insulation.  Teflon insulated
copper wire is ideal, as teflon insulation will not be affected by heat.
If Teflon insulated wire cannot be found, BE SURE that the insulation will
easily tolerate the heat generated.  Incidentally, the builder did not use a
thermostat, but just wired an in-line switch in the cord on the hot side
of the line.

It wouldn't do much good to duplicate the author's figures as things such
as the bike in question and other factors would influence them.  The bike
in question here was a Wing, which has a pretty stout electrical system.
Anyway the basic calculation is the important thing.  As to the layout pattern
that the author showed, it would be impossible to show it in ASCII
representation.  Just make sure that the wires are evenly spaced, do not
cross over, and that both ends come out close to one another.

EDITORIAL COMMENT

My training is in the electrical/electronics field, and I have built many
electronic kits and done a lot of amateur radio "home brewing".  Even
so, I evaluated the time, from beginning to end, to make a vest, including
shopping for materials, and decided that it just wasn't worth it.
Realize that I place a value on my time and am at a place in my life
where spending a few extra bucks to save some time is worthwhile.
One should also consider the fact that if something goes wrong, there
is NO manufacturer to fall back on.  Your mileage may vary.

--
Ken Franklin 	They say there's a heaven for people who wait
AMA     	And some say it's better but I say it ain't
GWRRA           I'd rather laugh with the sinners than cry with the saints
DoD #0126       The sinners are lots more fun, Y'know only the good die young
Newsgroups: rec.motorcycles