Salvage yard silicon steel

[CraigM]

Found at the salvage yard.

Pallet of loose transformer steel, grade M-22, .010 - .015 thick.

With magnet prices rising how can we put this material to good use?

CM

[Watt]

Found at the salvage yard.

Pallet of loose transformer steel, grade M-22, .010 - .015 thick.

With magnet prices rising how can we put this material to good use?

CM

Oztules has been talking about utilizing transformers with wind turbines, maybe he will chime in.  What is the cost of buying that steel if you don't mind?  I personally would be interested in trying a laminate beyond the standard ' E 'conomy stamps for use with wire that has a covering like thwn.  Anyway, good find if a stamp could be built to utilize an efficient E and I from that material. 

[CraigM]

Oztules has been talking about utilizing transformers with wind turbines, maybe he will chime in.  What is the cost of buying that steel if you don't mind?  I personally would be interested in trying a laminate beyond the standard ' E 'conomy stamps for use with wire that has a covering like thwn.  Anyway, good find if a stamp could be built to utilize an efficient E and I from that material.

I was quoted 70 cents per pound.

First thought that came to mind was to cut it into strips and wind an axial core around a circular form and use this for the stator. Similar to what Ed Lenz did at Windstuffnow.com.  M-22 is near the very low end in terms of core loss (believe M-19 is the lowest) and it may be worth the effort. I'm not sure how big of a factor the magnet force pulling on everything would play into this type of build.

CM

[Flux]

I really don't like the single rotor axial designs for the reason you mentioned, the axial pull is a major nuisance. It will save you a bit of cost using neo but if you want to use the cheaper ferrite magnets you will be better off using it dual rotor.

With a lot of patience you could certainly use that material to wind a torus and build an axial machinewith magnets on both sides like the Proven alternator. This is a good design bu is normally ruled out because of the trouble of finding a suitable core. You look to have found the source of core material and if you have access to a guillotine and can shear this into something like 20mm strips you have the basis to wind a decent toroidal core.

From the picture the shape doesn't lend itself to making a radial core easily. I far prefer the drum radial design to the single rotor axial but it looks as though a core suitable for a radial machine would be more difficult to make than a torus with that material.

What was it from ? I can only suspect it was a linear motor with those punchings.

Flux

[CraigM]

I really don't like the single rotor axial designs for the reason you mentioned, the axial pull is a major nuisance. It will save you a bit of cost using neo but if you want to use the cheaper ferrite magnets you will be better off using it dual rotor.

Thanks for the reply Flux,

Having never built a PMA I'm still in "sponge mode" trying to absorb all the information I can find on the subject. I've had Hugh Piggott's book on my night stand for nearly a year and understand the shortest route to success is with a proven design but I can't help but tinker a bit too, it's in my blood.

Here is a single rotor design. I thought it would be less expensive to build with good core material but I have concerns about the compressive forces exerted on the bearings. My only thought was to possibly make this a downwind design and let the wind force pushing on the blades offset the magnet to core compression. How much axial force is involved with this design anyway? I really have no frame of reference other then a gut feeling of "a whole bunch".

With a lot of patience you could certainly use that material to wind a torus and build an axial machinewith magnets on both sides like the Proven alternator. This is a good design bu is normally ruled out because of the trouble of finding a suitable core. You look to have found the source of core material and if you have access to a guillotine and can shear this into something like 20mm strips you have the basis to wind a decent toroidal core.

I read the post on this forum about "Rewinding a Proven stator" and understand (at least from photo's) how it is designed. At this point I believe it would be much too ambitious of an undertaking for my limited amount of talent. Still the upside is I do have access to a sheet metal shear. I work at a machine shop and although I'm not a machinist I have plenty of co-workers that are happy to do six-pack favors. I need to investigate this option further because I don't thoroughly understand the design and reasoning behind like poles (N to N) of the dual rotors.

From the picture the shape doesn't lend itself to making a radial core easily. I far prefer the drum radial design to the single rotor axial but it looks as though a core suitable for a radial machine would be more difficult to make than a torus with that material.

Here is a photo of more silicon steel from the same salvage yard. This material is 8" wide x 36" long and .013" thick. Only problem is I don't know what grade of material it is or if it's grain oriented or non grain oriented material. It looks pink in the photo but that's from the color of the storage building, it's actually light gray. Using this material I could laser, circle shear or mill 8" diameter disks and stack them into a smooth stator core. This is most likely the direction I'll proceed with. As I mentioned working at a machine shop has advantages and making a drum to match the core diameter shouldn't be overly troublesome.

What was it from ? I can only suspect it was a linear motor with those punchings.

I have no idea where this was used. There's a pallet of this material banded together that's over 24" tall. By my calculations there's somewhere near 2000 of these sheets. At 70 cents per pound I think I'll buy some just to experiment with.

Thanks to all for providing this wonderful wealth of talent and resources.

CM

[Flux]

I read this after commenting on your new post but I assume you will still look here.

I don't think the axial attraction force is significant as far as bearings go, you can use the single rotor arrangement as long as you can secure the stator core properly. With a strip wound core you will have to rely on epoxy or something to stop it sliding out like a flycatcher ( if you use such things over there).

Normally the drag on such machines with poor cores is considerable unless you rotate the core as well( and that defeats the main object of better cooling of coils directly mounted on metal. This seems to be excellent core material and it should be absolutely fine so don't rule out the single rotor option just because of the bearing worry.

Flux