Variable Parallel Gap
Subject: Variable Parallel Gap
Date: Sat, 7 Jun 1997 22:46:22 -0400
From: "Thomas McGahee" <tom_mcgahee-at-sigmais-dot-com>
I have just finished building and testing the prototype of my
Variable Parallel Gap. Basically, it is a flat version of an Richard
Quick Gap that is run with a vacuum cleaner motor to provide cooling
and better quenching.
The gap is made variable by making use of the properties of
parallelograms. The parallelogram structure allows the gaps to remain
parallel to one another at all times. Adjusting the parallelogram
changes the angle of the copper tubes and thus also the spacing
between tubes. The neat thing is that all the copper tubes adjust
equally at the same time.
The prototype uses five copper cylinders, each 7/8 inches in diameter
and five inches long. For the adventurous coiler, an optional plastic
handle actually allows the gaps to be adjusted while the circuit is
running. The prototype is variable from a total gap distance of 0
inches to .5 inches. The unit can be modified for other ranges as
desired quite easily.
The Variable Parallel Gap includes features that allow the vacuum to
remain high even though moving the copper cylinders changes the
geometry of the gaps.
It is beyond the ability of ascii art to convey anything beyond the
bare rudiments of the design, so I won't even attempt that here. I
have written up an eight page folder containing assembly text and an
overview drawing in reduced size showing the gap in both open and
closed positions so the workings can be clearly seen. This reduced
overview drawing also contains reduced drawings of all the pieces
separately shown. In addition, the remaining four pages contain
complete FULL SIZE drawings of all the basic parts except the wooden
vacuum enclosure (which is just a stupid box anyhow.)
The full size drawings can be used as a template to directly produce
a working model with a minimum of hassle. Although the prototype is
fairly large in size, you can easily discern from the drawings the
fundamental principles and design your own version to be more
compact. The prototype was designed to test out the idea, and can be
The prototype is working marvelously. No more tearing my hair out
because I can't get the stupid static gaps to adjust in anything
other than increments of one or more fixed gaps.
The drawings were done up on Autocad version 12. Since many of the
List members would not have any way to convert the drawings
electronically, I am making a package of the plans available for $2.
They will be shipped in a large format mailer so the pages will not
be folded. I wish I could provide the plans for free, but xerox
costs, large envelope and stamps quickly comes to $2 per package.
You may freely distribute the contents of the package.
If you have AutoCad version 12 then I can e-mail you the drawing
file. I can also produce a DXF file. The drawings are done up actual
size. No charge for e-mail copies. The text can be sent via e-mail
I will be going on to my summer assignment starting June 22, 1997,
so I may only be able to send out packages up to that date. Sorry,
but I don't know if the place I am going to has a computer and modem
that I can use to keep in touch with the List between then and
I would imagine that only a few die-hards will actually be interested
enough to fork over a couple of bucks, but you will have to get your
request in the mail as soon as possible if I am to be able to fill it
before I leave for my summer assignment.
Fr. Thomas McGahee
202 Union Ave.
Paterson, NJ 07502
Tel & Fax (201)595-6655
Don't forget to enclose the two bucks AND your mailing address AND
your e-mail address (so I can let you know it's on its way).
Fr. Tom McGahee