Muller Dynamo

[konehead]

Hi Mariu
Yes what you wrote describes all I wrote very well and much more simple...I am trying to get a video up it might take a bit of time - my rpm meter went bad while filming last one I think it is becasue the rotor is white plastic and was reflecting so am going to paint it flat black then put reflective tape on it.
Hi CrazyCut
the backing magnets behind my motor coils have alwasy giving me twice the speed at same draw since I built the two Romeor variants maybe 6 months ago...now its the backing mangets behind generator coils doubling speed and just discovered you dont need the generator coils or cores to get the big speed up this has lots of ramifications in future experiments and ideas such as air cores as genrator coils and the postioning of the backing mangets can be totally indipendent of the postioning of the cores of aircores of the generator coils too - they dont necessarliy have to be right behind all of them...I havent done loaded-genrator coils yet with backing magnets behnid them, as jsut "backed up" (pun) to testing motor coils only and influence of all the backing magnets on jsut the motoring-part of it...

[Scorch]

Hey everybody; just thought I would go ahead and upload another progress photo.
High resolution image here:
http://www.rodscontracts.ws/images/projects/muller/MullerParts.png

I did change my plans for the coil bobbins.
Was originally going to use 10X20MM ferrite rods with off-the-shelf, fiber, washers but decided to go with 10X25MM rods and custom made washers, cut from acrylic, which resulted in a slightly longer and significantly stronger bobbin.

I am straying away from Romero's original, sewing bobbin, design in several ways including larger coils wound with single conductor, Schottky diodes, different switching, timing capability through adjustable stator plate, etc.

My goal is to be able to use just one coil as the primary mover and the rest as alternator coils.
I do like the idea of off-setting the alternator coils to reduce cogging and provide a wider sine wave from each alternator coil pair.
But not sure how this might effect the motor coil pair. And will attempt to use just one coil as a monopole motor or maybe two operating independently.

I do have 14 of the 18 coils built and hope to do final assembly over the next few weeks.

There are definitely some workmanship issues with the laser cut rotor disks that I had made locally.
Every hole, for the magnets and hub, is not quite square so the magnets are not perfectly straight and I will use a couple modified appliance parts (idler pulleys) to help square the rotor on the shaft.
Apparently; trying to cut acrylic with a laser is not real practical because the acrylic diffuses the laser resulting in widening holes, and changing angles, as the laser cuts deeper.

This may be a vibration and alignment issue and I still may be inclined to machine a new rotor from the phenolic board I have on hand.
Or find somebody with a CNC machine who can do the same cuts with greater precision.

}:>

[mariuscivic]

Hi Scorch and all
Very nice toy you got there. I also cutting my disks with a laser cutting machine and they are not perfect. I just found a CNC machine in the other side of my country and tomorow I'll make a call to ask some prices. I want to stay at the romero design but i just cant find the ferrite cores (6mm/15mm) that fits into the sewing bobbins.
There is something that keeps ringing in my head: the washer between the coil and the backing magnet. It supposse to make a shield at the backing magnet.
This can make sense : the N of the magnet is shielded and it uses lenz as the N (and this only half wave)
What do you think?

[Scorch]

I believe the washers are kind of like a "shield" or maybe more like a "focusing aperture" that also helps to hold the magnets.

There will also be a 1/4" of acrylic between my coils, and the washers with biasing magnets, which is also how I think Romero's was set up.
The space between the ferrite rods and the biasing magnets is, probably, not very significant.
More space just means you might need a stronger magnet or different position.

On the other hand, the size of the hole in the washer MIGHT be significant just depending on the individual build and size of ferrite rods.
I used ferrite rods from Newark (Stock No: 63R5821 Manufacturer Part No: ROD10/25-4B1) and will start with 3/8" ID X 1" OD steel washers.

I also used 1/16 acrylic and a 1 3/8" hole saw, to make the coil ends, which resulted in a finished washer around 1 1/4 OD which was then drilled to tightly fit the rods and fastened with cyanoacrylate adhesive.

I did discover some minor discrepancies in the consistency of size of these ferrite rods.
The 25mm long rods are actually a little smaller diameter than the 20mm long rods and, sometimes, there is even a few thousandths of an inch difference just from one end to the other.

I do my best to fabricate parts to properly FIT but, THEN, the MANUFACTURER, with their "PRECISION MACHINE", screws it up!

}:>

Hi Scorch and all
Very nice toy you got there. I also cutting my disks with a laser cutting machine and they are not perfect. I just found a CNC machine in the other side of my country and tomorow I'll make a call to ask some prices. I want to stay at the romero design but i just cant find the ferrite cores (6mm/15mm) that fits into the sewing bobbins.
There is something that keeps ringing in my head: the washer between the coil and the backing magnet. It supposse to make a shield at the backing magnet.
This can make sense : the N of the magnet is shielded and it uses lenz as the N (and this only half wave)
What do you think?

[konehead]

Hi Scorch
My theory is the flat washer between core and backing magnets behind the cores, works as way to concentrate the flux of  the magnet uch more onto the backside of the core, so that the core will become very easily "flippable" in its polarity, and for the backing magnet not to affect the core so much it becomes sort of solid-polarity throughout;  so that it would be clashing on the rotor magnets as they approach, which would slow the rotor or even bring it to halt.
the "bloch wall" in a core is the point near the center of core, which is point where the core changes its polarity so it has N one side and S other as the core will be when polarized.....idea is to pull that bloch wall way back near the back-end of core with the backing magnets, so that the core will still attract rotor magnet, then repel with some good force instantly since the core's polarity is sort of on a teeter-totter from the backing magnets and the repel from polarity-flip happens right when rotor magnet moves past so this is a positon for roto magnet to get shoved, and not pullsed back, slowing the rotor, which is what lenz-law lugging does.....(theory anyways)