Working Magnetic Motor on you tube??

[Morgenster]

I wonder if these slight discrepancies would lead to the 45g difference between my 303g rotor (HDPE + magnets + two bearings) and the required 258g rotor of the original. Don?t know what the density of HDPE is.

Hi Omnibus.

If I'm sufficiently awake to do the math correctly (almost 2am UK time !), the increased dimensions of your rotor would add a mere 6% to the total weight - though this only being the case if you were comparing like-for-like of HDPE alone. In such a case the extra dimensions over Jason's would only bring it to a tad over 274g.

However, as there are added weights of the bearings and magnets in both cases then the weight contribution of the added HDPE material becomes even less (HDPE clearly being lighter than that of the bearings and magnets), so the extra dimensions certainly don't appear to be the main contributor to the significant weight difference.


All the best,

FunkyJive

Funny. I get approximately 260 grams. What formulas did you use? Seems to me the 258 grams Al posted should be just about right for the materials Omnibus used on a slightly larger scale.
the density of the material should be some 892 grams/liter.

[Morgenster]

Come to think of it: there's some serious issues working at this scale.

Even if somehow you manage to get your rotor to 258 grams to the dimensions posted by Al, there's still the matter of weight distribution within the piece itself and the balance of the rotor.
Car wheels that wheigh in at some 20 kilos start to get a little vibration at 100km/h (or 1200 rpm) if the balance of the wheel is off by some 50-100 grams.

[ezzob]

Thinking, can one stator have One-way Bearing

http://rc-toy.de/multistore/product_info.php/info/p655_H60021T-One-way-Bearing.html

[Spartane]

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

Presumably this would be best applied to the rotor magnets, and would contribute to the magnetic delay that's needed to get this thing going.  At this point, I think that it's important to note that Al's motor ran equally well in both directions, suggesting to me that a magnetic delay is probably occurring.

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...

[Omnibus]

@All,

Now I've replaced the rotor N42's with N35 neos (~28mm separation)   Again, achieving AGW is relatively easy, as was with the N42's, but I still don't see any acceleration in this rig I'm studying. Unfortunately, I still don't have the equipment to check quantitatively what appeared to be acceleration in the other setup I was studying. I'll stick with this contraption for now because it's the closest to the original. Will have to check different ring magnet-stator bearing combinations.