AOH :: NEWMAN11.TXT Design Considerations for Rotating Magnet Newman Motors
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Subject: DESIGN CONSIDERATIONS FOR ROTATING MAGNET NEWMAN MOTORS

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Note: The views expressed herein may or may not represent the position of
Joseph Newman and, as informational material, are provided here from
submissions by other individuals interested in the technology
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DESIGN CONSIDERATIONS FOR ROTATING MAGNET NEWMAN MOTORS

(C)opyright 1991-1996 by -

Ralph M. Hartwell II
715 Jefferson Heights Avenue
Jefferson, Louisiana 70121-1110

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The motors demonstrated by inventor Joseph Newman to date have
been  of  two  types.    The rotating  magnet  armature  version,
similar  in appearance to a conventional DC electric  motor,  and
the  reciprocating or "vertical" design,  which resembles a giant
solenoid magnet.    This discussion will concern itself with  the
first type of motor, the rotary Newman machine.

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OVERVIEW -

The   rotating  magnet  Newman  motor  is  deceptivly  simple,
apparently consisting of nothing more than a large coil of  wire,
a  rotating  magnet  armature,   and  a  commutator.    Unlike  a
conventional DC electric motor,  however, the Newman motor has no
iron  or  other ferromagnetic materials in the magnetic  circuit.
In fact,  the presence of any ferromagnetic materials except  for
the  magnetic  armature severly degrades the performance  of  the
machine.

A Newman motor is assembled sort of "inside out" when compared
to a regular DC electric motor; that is, the coil is wound around
the  magnet,  and  the  magnet rotates,  while the  coil  remains
stationary.    A  commutator  is necessary to  perform  the  dual
function  of reversing the polarity of the voltage applied to the
coil as the magnet reverses position twice per revolution, and to
interrupt the current flow through the motor coil many times poer
revolution  according to Newman's theory.    The design  of  this
commutator  is  quite  critical to the proper  operation  of  the
motor, and is covered in a seperate paper written by this author.

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THE COIL - OPERATING VOLTAGES -

The  coil is usually a simple solenoid design,  with  multiple
layers  of wire wound on it.    Depending on the applied voltage,
the wire gauge will vary from 8 gauge to about 32  gauge.    Thge
lower voltages use the larger diameter wire, and the high voltage
machines will use the finer wire.   Newman has used both extremes
on his various designs.   Note that while Newman prefers the high
voltage designs (he feels the high voltage devices have less loss
because of the lower current in the windings) he has successfully
demonstrated  a machine operating on 12 volts DC power input.

My  suggestion is to use a voltage no higher than 300, due  to
the  problems  with the very high back voltage generated  by  the
device.    Output voltages of 50 times the input voltage are  not
uncommon with the larger units.   These great voltage spikes  are
difficult to control, and tend to destroy test equipment connect-
ed  to the Newman motor*.   Also, high voltage  machines  require
many  more  turns of fine wire, with a rather rapid  increase  in
construction effort and cost.

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*Note: the voltage spiking problem has been solved with the latest
commutator designs. This permits the utilization of higher voltages without
the earlier back-emf problems.
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THE MAGNET -

Mewman motors.  My recommendation is to try surplus houses,  such
as Fair Radio,  Jerryco,  or suppliers such as Edmund  Scientific
Co.    These  folks usually have surplus magnets in various sizes
at reasonable prices - at least when compared to new magnets.

What is the best type of magnet*?  Well, for the experimenter,
it's most probably whatever you can get at a good price.   Newman
motors have been built with everything from Alnico (C) magnets to
the latest super-powered rare-earth magnets.   A popular material
is   ferrite   composition,   of  the  kind  commonly   used   in
loudspeakers.    These  magnets are usually readily available  in
surplus catalogues,  and are not too unreasonably priced.    They
also  are  usually  made available in  large  quantities  on  the
surplus  market,  which is a good thing,  since you will probably
need quite a few of them,  depending on the size of the motor you
are building.  [Note: neodymium magnets have been used]

If  you use magnets such as ferrite loudspeaker magnets,  they
are usually stacked end to end and covered with something such as
epoxy or fibreglas to prevent the assembly from flying apart  due
to  centrifugal  force  while in high-spoeed  operation.    If  a
single stack is not as powerful as you would like,  you can place
several stacks side-by-side to increase the magnetic field.   The
magnets  may  also be placed inside a non-metallic tube  to  hold
them in place.

How large should the magnet be?   I suggest that the weight of
the  magnetic material in the rotor be made about 1/4 the  weight
of  the  wire used in the coil of the motor.    This  is  not  an
absolute rule, just a first approximation for testing, but it has
worked well in previous designs.

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THE COIL -

What about the coil size?   Remember that as the machine grows
bigger,  everything  interacts  to cause the price of  the  parts
needed to increase!    Design the coil so that it's axis is about
3/4  to 4/5 as long as the rotating magnet assembly.    The coiul
should  be  close  in dimensions to  a  so-called  "square"  coil
design;  that is,  a coil which is as wide across its diameter as
it  is  long.    This design comes close to giving  the  greatest
inductance with the smallest mass of wire, and also keeps as much
of the wire as close to the magnet as possible.

Since  the  magnet rotates end-over-end inside the  coil,  the
length  of  the assembled magnetic rotor  determines  the  inside
diameter  of the coil.    Let's take a few figures as an example.
The  following  is  not necessarily a  recommendation,  but  just
serves as an example...

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Note: in the newest designs, the magnetic rotor configuration is designed
differently.
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Suppose the magnet when assembled is 11 inches long.    If  we
allow  1/2 inch clearance between the ends of the magnet and  the
inside  of  the coil form,  that will make the coil  form  inside
diameter about 12 inches.    Allowing 3/4 of that size,  the coil
would be about 8 inches long.

Since this is a small motor,  we might want to make the coil a
bit  longer,  perhaps a full 12 inches.    This will allow us  to
have a bit more copper wire in the magnetic field of the  magnet.
The  extra wire won't be as effective as the wire near the center
of the coil, but every bit helps.

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WINDING THE COIL -

The  thickness of the wire wound on the coil ,depends  on  the
size of the motor,  and the strength of the magnets.   The bigger
the motor,  naturally, the bigger the magnet, so the more wire is
required.    I suggest making the wire thickness about 1.4 to 1/3
the  inside diameter of the coil.    In this example,  this would
make the winding thickness about 3 to 4 inches.    This makes the
outer  diameter  of the coil about 16 to 18 inches  in  diameter,
with a winding thickness on each side of the form.

You  can calculate the amount of wire needed by computing  the
area  which will be occupied by the windings.   To do this,  take
the length of the coil,  in this case, 12 inches, and multiply it
by  the  winding thickness,  which is 4 inches in  this  example.
So, 12 X 4 = 48 Square inches.

The wire will not occupy the entire volume,  since the wire is
round,  and  when  wound on the form,  will not fill  the  entire
volume.    About 70% of the space will be filled by the wire.   A
table of wire data,  such as the one found in the Radio Amateur's
Handbook, will allow you to figure how many turns of wire will be
required.

Then, you can calculate the length of an "average" turn on the
coil by figuring the length around the coil when the coil form is
half full,  which, in the case of our example here, will be about
16 inches.  (12 inches for the inside of the form,  plus 2 inches
of  wire  on each side of the form when it is half  full).    So,
3.1415926 X 16 = 50.26 inches per turn.

Let's  suppose the wire we have chosen measures 0.05 inches in
diameter.    If we were able to wind it evenly so that each  turn
were  side by side,  we could get 1 inch / 0.05 inches per turn =
20 turns per inch.   So, 20 TPI X 48 square inches = 960 turns on
the coil.    Since we won't be able to get all those turns on the
coil  so neatly,  we can assume between 70-80% of them will  fit.
Therefoire,  960 turns X .75 = 720 turns expected.   Always buy a
bit  more  wire than you figure you'll need,  just in  case  your
calculations  are a bit off,  or in case you really can wind  the
wire really neatly!

Figure how much wire is needed - 720 turns needed;  lets allow
an  extra  15%,  so 720 X 1.15 = 828 turns.    828 turns X  50.25
inchges per turn = 41615 inches,  or 3468 feet of wire  required.
The wire table will tell you how many feet of wire are in a pound
for the size wire you have chosen.

A  suggestion  at this point - It will probably be cheaper  to
buy a 50 pound spool of wire then to buy only a couple of smaller
spools  of  wire if you need only 25 pounds or  so..  check  with

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INSULATION CONSIDERATIONS -

Beware  of  winding a coil for a motor which will  operate  on
high  voltage without using insulation between layers of wire  in
the  coil.    It is entirely possible to have a flashover between
windings when the motor runs, due to the very high pulse produced
by  the  motor.    This is the reason  I  suggest  starting  with
relatively  low  voltages.  It also makes the  commutator  design
easier.*

Copyright 1991-1996, Ralph M. Hartwell, II

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*The latest commutator design enables higher voltages to be utilized.
Note: The above article was written several years ago.  The principles
described above are generally applicable "across the breadth of the
technology."  However, considerable improvements to the commutator design
have been made in the recent past.  These improvements are intended to
actually reduce the intensity of the sparking by distributing the physical
connections over a wider area. The reader should bear in mind that there
are TWO totally different design systems (but many sub-configurations
within each basic design): there is one commutator design when the energy
machine is intended to function as a GENERATOR and a totally different
commutator design when the energy machine is intended to function as a
MOTOR.  The latest design improvements to the commutator system apply to
the machine operating as a MOTOR.  Subsequent torque can be utilized for
mechanical systems or can be used in conjunction with a conventional
generator.

Evan Soule'
(504) 524-3063
P.O. Box 57684, New Orleans, LA 70157-7684

The latest Wiring/Construction Diagram is available to all purchasers of
Joseph Newman's book. It is not advisable that you contact Joseph Newman
directly unless you have read and mastered his book. Questions/insights