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News announcements and other topics => News => Topic started by: nitinnun on March 01, 2009, 08:52:29 PM

Title: iron cores, for my electromagnet motor ? (question).
Post by: nitinnun on March 01, 2009, 08:52:29 PM
i want to build my own home made induction motor.
using electromagnets only.


which of the following iron cores,
would be the strongest ?


1:
thick steel pipe.


2:
dozzens of "strands",
of steel wire,
bundled together into a "bar".

that looks like this, from the top:

      oooooo
     ooooooo
      oooooo


3:
a dozzen turns of steel wire,
wrapped into a "donut".
shaped like a donut that homer simpson might mindlessly consume.

with the wire coil,
wrapped around the outside,
of the steel donut.


4:
a dozzen turns of steel coil,
shaped like a solenoid wire coil.
with the magnet wire wrapped around its outside.

that looks like this, from the side:

        ====
        ====
        ====
        ====
        ====
        ====


5:
thin steel sheeting,
which is wrapped into a tube.


6:
thin steel sheeting,
which is wrapped into a "bar".


7:
thin steel sheeting,
cut into sheets.

the sheets stacked into a cube.
(and wrapped tightly together, by tape).
Title: Re: iron cores, for my electromagnet motor ? (question).
Post by: SomedayIsle on March 02, 2009, 01:04:40 PM

I'd go with the steel pipe for it's obvious multipurpose use.....


In case the infernal machine refuses your demands.


Title: Re: iron cores, for my electromagnet motor ? (question).
Post by: z.monkey on March 02, 2009, 01:38:02 PM
Quote from: SomedayIsle on March 02, 2009, 01:04:40 PM
In case the infernal machine refuses your demands.
Confounded Technology!

Most motors use laminated sheets of soft iron for the magnet cores.

The sheets an be cut and stacked to accommodate the radius of the armature.

Tight clearances between the electromagnets and the armature is important...

Been there, done that...
Title: Re: iron cores, for my electromagnet motor ? (question).
Post by: X00013 on March 02, 2009, 06:59:42 PM
http://search.nasa.gov/search/search.jsp?nasaInclude=magnet+motor&entqr=0&output=xml_no_dtd&sort=date%3AD%3AL%3Ad1&ud=1&site=nasa_collection&client=nasa_production&ie=UTF-8&oe=UTF-8&simple_start=&news_start=&images_start=&videos_start=&podcasts_start=&baynote_start=&baynoteOrGSA=baynote
Title: Re: iron cores, for my electromagnet motor ? (question).
Post by: nitinnun on March 07, 2009, 01:45:27 AM

i came up with a solution.


i will wrap magnet wire, around a flat piece of cardboard.
then wrap thin steel sheeting, around the magnet wire.

my reasoning is that i only need steel, where i need the magnetic field.
and i only need the magnetic field, close to the rotor.



i looked at a box fan motor.
the box fan motor had a steel core, holding the magnet wire.

but otherwise, little of the steel was contacting the rotor.
most of the magnet wire, wasn't even close to the rotor !



i suspect that ALL of the magnet wires magnetic field,
goes into the small amount of steel, which is contacting the rotor.

compared to having steel all around the coil.
and having the magnetic field wasted that way.
Title: Re: iron cores, for my electromagnet motor ? (question).
Post by: nitinnun on March 07, 2009, 01:55:00 AM

i will also be using the side of the coil,
to both repel and attract the rotor.

like tesla did, on atleast one of his induction motors.


i will not use the EXTREMELY INEFFICIENT monopole method,
which seems to be common in the mainstream.



i made a crude solenoid magnet,
using a different method than above.

it could pick up a pair of steel pliers, if i used the side.
the monopoles on it, couldn't pick up much of anything.


the side of the coil is superior,
for the stator coils of the motor.
Title: Re: iron cores, for my electromagnet motor ? (question).
Post by: jadaro2600 on March 07, 2009, 02:04:48 AM
Three suggestions:

If the magnetic field or current proximal to the magnetic field to-be-formed is going to be changing, then I would use ferrite which you can craft to you own dimensions - like an epoxy and powdered iron dust mixture.  This will maximize flux and minimize the heat losses. OR, you could create multiple singe non attached out-of-the electrical circuit wires made of steel.  Which brings me to the third suggestion... these wires would have to be insulated though, like floral wire, or regular mag wire can sometimes be purchased in nickel or steel with insulation.  If the current will be continuous on these wires in one direction, it has potential to for a strong field what with it already being ferromagnetic.