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[robbie47]

Check the shadow of the main rotor in @Al's video. the rotor is not in the exact centre. You can compare the shadow distance with the static bits around the outside of the main rotor.

Edit. also looking at the shadow of the centre of the main rotor in the strobed video the same effect can be seen, however would perfer it if someone with better picture analysis would confirm this observation.

How about vertical wobble (variation in hight)?

[RunningBare]

Fingers crossed guys and gals


http://www.steorn.com/forum/comments.php?DiscussionID=60180&page=2#Item_5

Turbinator wrote:
 
Without going into too much detail, I had a sustained rotor yesterday evening while fooling around around with the stators; The stators were not rotating but oscillating slightly (and with a rod mag attached to each stator - like i said i was tinkering!), the rotor was hand spooled and left to run down while i was doing something else..... strangely it held at around 300rpm. I will investigate further and keep a camera handy.

[dean_mcgowan]

I suppose Turbo has just as much right to infer things as Al does .. <pours another green tea blend gets the yummy white honey out and reclines to watch the circus unfold>

[hydrocontrol]

Wow.  I had tried something like that with my set about a week ago except that I used two small rod magnets attached to the stator so it looked like  --O-- . I only did it to one stator. I did notice it pulsed the rotor and seems to improve slow down times but I could not get it to do anything else but to wind down at which point one or the other outer stator arms would stick to a rotor magnet. Guess I will have to go back and play with one arm setup..

Fingers crossed guys and gals

http://www.steorn.com/forum/comments.php?DiscussionID=60180&page=2#Item_5

Turbinator wrote:
 
Without going into too much detail, I had a sustained rotor yesterday evening while fooling around around with the stators; The stators were not rotating but oscillating slightly (and with a rod mag attached to each stator - like i said i was tinkering!), the rotor was hand spooled and left to run down while i was doing something else..... strangely it held at around 300rpm. I will investigate further and keep a camera handy.

[Yadaraf]

Fingers crossed guys and gals


http://www.steorn.com/forum/comments.php?DiscussionID=60180&page=2#Item_5

Turbinator wrote:
 
Without going into too much detail, I had a sustained rotor yesterday evening while fooling around around with the stators; The stators were not rotating but oscillating slightly (and with a rod mag attached to each stator - like i said i was tinkering!), the rotor was hand spooled and left to run down while i was doing something else..... strangely it held at around 300rpm. I will investigate further and keep a camera handy.

RE: Similarity between turbinator's oscillation and the Lego device(?)

Not to clutter this thread up, but if the Lego device is to be believed, then its rubber bands might be contributing to a similar oscillation phenomenon as the spinning rotor mags pass by the fixed stator mags -- hunting/oscillating during passage due to the elasticity in the bands, but never really "locking in."

In any event, turbinator's device is starting to look like a Lego-WhipMag hybrid. 

Cheers,

Yada ..
.

[Grimer]

One of the things that Sean mentioned on the Steorn site was the need for "poor quality" magnets. 

...

So maybe Al used older crappy rotor magnets that he happened to had lying around, and the rest of you are using fresh, off-the-shelf magnets that have their magnetic domains so firmly locked into place, that they cannot be modulated by the spinning stator magnet.

Anyway, something to consider...

I think that is a very good point. If one is to generate energy one has to cut a chunk out of the BH loop in the opposite sense from the energy loss (refrigeration) direction. Maybe the change from GW to AGW marks that change in direction. Mmmm.......very interesting. I hadn't looked at it that way before but it's so obvious when you think about it. That is what the change in rotor direction is telling us. 

[Omnibus]

I will have to send my rotor to be milled down to 258g so I won?t do experiments till probably Tuesday.  In the meantime I won?t stop discussing theory but not here. Please @Grimer, @Spartane and others who also want to discuss theory would you mind moving to the debate thread to avoid cluttering this thread devoted solely to the technical issues regarding the replication of @alsetalokin?s device.

[Yadaraf]

One of the things that Sean mentioned on the Steorn site was the need for "poor quality" magnets. 

...

So maybe Al used older crappy rotor magnets that he happened to had lying around, and the rest of you are using fresh, off-the-shelf magnets that have their magnetic domains so firmly locked into place, that they cannot be modulated by the spinning stator magnet.

Anyway, something to consider...

I think that is a very good point. If one is to generate energy one has to cut a chunk out of the BH loop in the opposite sense from the energy loss (refrigeration) direction. Maybe the change from GW to AGW marks that change in direction. Mmmm.......very interesting. I hadn't looked at it that way before but it's so obvious when you think about it. That is what the change in rotor direction is telling us. 

How about crappy supports -- ones that wobble enough to resonate like the Tacoma Narrows bridge [a.k.a Galloping Gertie].

It's possible the new and very "tight" replications are so different from Al's cobbled together original that some natural [and potentially catalytic] resonance (oscillation) has been lost.

Perhaps mounting the stators to someting less rigid -- like hard rubber -- would induce resonance.  Perhaps the same is needed for the rotor.  Studying the resonant frequency (300 rpm ==> 5 cps?) could be useful.  The closest natural phenomenon that comes to mind is the Schumann resonance of 7.8 Hz (~468 rpm).

... Schumann resonance:  http://147.175.143.11/schr-e/index.php     

Time to loosen up? 

Cheers,

Yada ..
.

[MeggerMan]

@All,
Looks like Turbinator on the Steorn forum has achieved sustained rotation, in his last post he sort of implies that he is holding the stator magnets in his fingers which may not be good.
 http://www.steorn.com/forum/comments.php?DiscussionID=60264&page=1#Item_5

I hope this works out and become the first independant running replica.
Couple of pages back someone mentioned ceramic bearings, these are available quite easily from r/c model places and ebay, they made from stainless steel, ceramic ball bearings and have a special low friction lubricant.
They last a lot longer, are not effected by magnets, so a good choice I think.
Here is a lightweight bearing I found 5x8x2.5mm:
http://www.modeltech.co.uk/catalog/product_info.php?cPath=102&products_id=478&PHPSESSID=05c675e5dd4ad987c71085cfa21e8733

There seems to be a lot of discusion about critical rotor weight, I would concentrate more on the stator friction if I were you.
You could always mill out a circular slot in the disk if you want to be spot on but I think time would be better spent looking at the major point of friction, that being the stator bearing - it spins faster, has very little inertia and I have seen from my own tests that ball bearing lockup from the stator magnet is a major problem.

I think we are good to go now...

regards
Rob

[Omnibus]

@MeggerMan,

Did you read one of my latest posts? There I explained that I replaced the bearing with a brand new one. As a result I couldn't latch it in AGW no matter how much I tried. Then I applied penetrating lubricating oil to it, as I've done with the older ones, and locking it in AGW became again straightforward and easy. The importance of this penetrating lubricant cannot be overestimated. Achieving a steady AGW latch isn't a problem at all, this is what my experiments show. The main problems seem to again revolve around the proper rotor weight and the proper rotor and stator magnetic induction profiles. Until we get them adjusted as they are in the original success is hardly likely, I think. I'm curious what's your rotor's weight?