ferrous or non-ferrous backing disk on radial generator?

[philip]

Hi Gang,

With respect to the backing plates in the radial turbine generator, would aluminum or composite have an advantage over iron?

How does the backing affect (shape) the magnetic field between the coils?

Thanks

Philip

[monte350c]

Philip,

The flow of magnetic flux is something like the flow of electricity. Each magnet is like a little battery. You have to complete the 'circuit' for strongest flux in the airgap.

So that indicates use of ferrous materials in those areas. If it's not in the flux path, other materials could have weight advantages.

Ted.

[Waterfront]

If you back your magnets with non-ferromagnetic material, your magnetic circuit won't be as strong, so, for a backing plate, don't use aluminum...

A simple test, if your magnets stick to it, then it's a good material, otherwise, you'll get much less power out of it...

[steeolico]

My first generator had built him/it with flat of I steel inox.... Terrible choice! The power in exit was practically a tithe part of that with flat in sweet steel!  

If you have the dishes in accioio inox you can always use them to close the blades.  

Translation software  

Stefano (Italy)  

[Victor]

I believe when Stefano says accioio inox, we would read stainless steel

[elvin1949]

I thought the same thing.

That software can be hard to figure sometimes.

[ghurd]

Yes. Sweet is regular. Inox is stainless.

[coldspot]

This is something I also was wondering-

On a 7 1/4" saw blade type minimill-

Could a non-magnetic backer be used behind the sawblades?

wouldn't this force the flux to flow back around thru the next magnet?

Just some thoughts I have for next one.

[nothing to lose]

If a magnet don't stick to it it probably won't work for conducting flux, nor reflecting it back as was kinda asked. Also I have been told many times there is really nothing that will block or reflect magnetic flux. I had a project I needed to block or reflect the flux from an area where I don't want the flux, been told many times it can't be done though, so you can't use a backing to do it on a rotor either.

I test thickness by sticking a magnet to the steel, touch the back with a screwdriver. If the screwdriver sticks to the steel then you are losing flux out the back, it's not all being conducted to the other mags beside it.

Not sure if I am correct, but I beleave as long as you have a steel ring as big as your mags you can mount the mags to the ring, the ring will conduct the flux, then you could mount the ring to anything you want for a rotor. Provided of course the material of the rotor is strong enough to hold the rotor rings.

So if you took a steel ring of 14" inner and 16" outer diameter, and mount 2" long mags on it. Test it for flux leakage on the back side and don't have any losses, then you could mount the magnet rings onto aluminum or even wood if it's thick and solid enough to hold the mag rings apart from the tremendous pull they will have towards each other.

Wood of course may not be a good choice since it may swell and warp.

[philip]

I guess I am still confused?

My thinking is that the only critical part of the magnetic field is the field that passed "through" the coil.

I am wondering why the field on the back side of the magnet is important since it does not pass through the coil?

Does the fact that the back-side field is interacting with the iron rotor somehow shape the field through the coil (on the otherside) in a beneficial way? If so then how is this done?

Thanks for your patience.

Did Maxwell's Equations in Phys 3000 but nothing intuitive that I can use now

[nothing to lose]

"Does the fact that the back-side field is interacting with the iron rotor somehow shape the field through the coil (on the otherside) in a beneficial way? If so then how is this done?"

Yes kind of. The magnetic flux flows through the wire coils, that makes the currant flow, but the steel or iron backing behing the magnets flows the flux to the other poles beside it so it makes a loop. Kinda of completing a circuit. Think this way, flux flows from magnet north pole through wire coil to a mag south pole, then through steel/iron to a another pole, back through another coil and to a pole, through steel/iron to the first pole. Can't really think how to say the path really right now, try this hope close!!

N, coil, S, N pole to iron to next S pole, N to coil to S, n pole to iron to south pole. Makes a complete loop.

South pole would be in first steel rotor, N facing coil, back rotor S facing coil and N facing steel rotor, this pulls the flux throught he coil. The you have two oposite mags side by side so the flux flows from N to S poles through the steel rotor, then back through the coil and back to the original magnet poles. A complete path!

[coldspot]

I still don't see why a non-magnetic backer behind the steel of say a saw blade wouldn't help keep the flux flowing the right way.

Or maybe I'm just crazy.?

[nothing to lose]

"non-magnetic backer"

Do you mean just more steel that is not magnetized, or something magnets won't stick to like copper or aluminum?

In order to have any effect on the flow of flux I think it has to be like steel to conduct the flux from magnet pole to magnet pole. If a magnet does not stick to it I think that means the flux also is not being conducted, just passing though it like it would a piece of glass. No effect on flux.

If you have flux comming off the back side of a thin saw blade and it holds to a screwdriver or such, then putting a ring of plain steel on the back of the blade behind the mags will conduct that lost flux and flow it to the opposite poles of mags to the sides. Same as using a thicker piece of steel to begin with would have.

 N_S_N_S  conneted by the steel. Maybe similair to using wire to conduct electric.

 Now say you use aluminum, wood, or glass as a backing glueing on the mags. N S N S notice no connection to poles there, like sitting batteries side by side without wires, the Flux or power is there, but not flowing.

 Using aluminum, wood or such non-magnetic materials then behind a saw blade would not have any effect on the lost flux, should be same as still only having the sawblade, though it might add strength to the blade to prevent flexing.