Opposed Twin Coil swap….TG and others…

[phil]

As I understand it the coating is put on the laminations to avoid what are called "hysteresis" losses. Essentially to cut down on " eddy " currents within the metal of the coil core, dividing into laminations also helps in this regard, as opposed to having the core of solid metal.
The above losses if not addressed tend to heat the core. Of course, we all know of older coils and coil designs that do have solid cores.
It seems that magneto coils are small enough that this may not be much of an issue, it certainly is an issue on transformers that handle a large amount of power.

http://www.omc-boats.org
http://www.aerocraft-boats.org

[joecb]

Steel used for magnetic core laminations is soft steel, specifically low carbon high silicon steel.. no coating to the best of my knowledge.
Joe B

[jnjvan]

Phil and Joe are both correct. Some lams are coated, many are not. Those that are not coated rely on a thin oxide layer to provide some resistance between lams. If these is no resistance, or if the material was not laminated, eddy current losses would reduce the efficiency of the coil. The eddy currents circulate perpendicular to the axis of the core, hence the effectiveness of laminating the core.

[RICHARD A. WHITE]

quote Buccaneer:

Richard, I tried searching for “magneto laminations material”, etc., to see
what coatings or special properties the metal is made of, but only
came up with a bunch of engineering gobbly goop!

Yup, exactly what I came up with so I figured if it worked for that long I aint gonna muck it up 🙂

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[Buccaneer]

Said Gobbly Goop…..
"Explicit nonlinear homogenization for magneto-electro-elastic laminated materials
Stefano Giordano
Mechanics Research Communications
ABSTRACT In this work we propose an explicit procedure for the homogenization of laminated magneto-electro-elastic nonlinear materials. It means that we determine the effective response of a multilayered structure composed of materials with an arbitrarily nonlinear and anisotropic coupled behavior. In order to obtain a general theory, we take into consideration an arbitrary lamination direction, which is useful to exploit the anisotropic character of components. This technique is characterized by closed form expressions, which can be simply implemented through the basic operations of tensor calculus. To conclude, we discuss some particular cases and various applications."

Prepare to be boarded!

[garry-in-michigan]

About those laminations – As the Flywheel turns … A soap opera for outboard lovers 😀

The magnets in the flywheel create a changing magnetic field in the surrounding conductors. This is focused by the core and harnessed by the wire coiled around it. It takes energy to magnetize Iron as all the little molecules must be alligned. It was found this was easier to do if the iron was broken into little pieces as electrical currents in long lengths of metal created heat and resisted the magnetic field. (Higher frequency coils use powdered iron and a nonconductive binder.) So the coil core is laminared and each piece is insulated with a non conductive paint to cut down on these edie currents. So if a coil gets out of position and the pole shoes rub against the flywheel, removal of the paint is not too bad. However if the metal is beat over so as to short the laminations together, this is bad as it will convert some of the electrical energy to heat and lower the amount available for ignition. At normal operating speeds this would be no problem, but it could be trouble at cranking speeds if there were other issues. (Dirty points, bad insolation, worn plug gap, weak flywheel magnets. etc..) If in doubt, clean up the rough edges and repaint.

[Buccaneer]

Re: About those laminations – As the Flywheel turns … A soap opera for outboard lover

Was this the episode where the Magnetic Mrs. Field runs away with Eddie?
Do any of you ever paint your laminations to make them look pretty and
to keep the rust at bay? If so, should a person use non conductive paint?
Will have to do a search for said paint….. pretty sure my Dupli-color
doesn’t tout being non conductive.
Thanks for the input! TG

Prepare to be boarded!

[thumper]

Nice write up. I will save this one in my archives on the computer. That way if the forum goes down again I won’t loose all the info like last time.
Thanks for the reboot Chris. Congrats on the new marriage as well!

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