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[Craigy]

cool stuff sean , starting my base plate today, although am tempted to plug a few of the new magnets into the old model i have..even though the measurements are wrong. The stator holders are they just brass shaft , friction fit to bearing and magnet?

[Grimer]

The rc helicopter bearings just arrived. However, they look too small--3/16". They arrived in a huge box with no details whatsoever. Can these bearings be used ... Another glitch.

Huge box with no details? 
Better check for polonium.

[CLaNZeR]

cool stuff sean , starting my base plate today, although am tempted to plug a few of the new magnets into the old model i have..even though the measurements are wrong. The stator holders are they just brass shaft , friction fit to bearing and magnet?

Hi Craigy

I lathed down 6mm rod to around 3/16 one end and 3mm the other.
Then I mounted the magnet in the lathe and placed the Brass Rod in the lathe tailstock drill chuck. Then just gently squessed it in. They went in nice and square and a really tight fit.

I cut some 3mm brass tube I had to make the 6mm spacers and the bearings mounted in polycarbonate mounts either side.
 
(http://www.overunity.org.uk/ocpm/statorH3.jpg)

On the finished ones press fitted I just threaded the end so I could put a nut on the end and pull fit the shafts into the bearings.
(http://www.overunity.org.uk/ocpm/statorH4.jpg)

Good luck mate

Cheers

Sean.

[CLaNZeR]

The rc helicopter bearings just arrived. However, they look too small--3/16". They arrived in a huge box with no details whatsoever. Can these bearings be used ... Another glitch.

Huge box with no details? 
Better check for polonium.

ROFL 

[MeggerMan]

Hi Sean,
Cracking progress!
800 rpm rotor speed, so you need 4 x that for the sync on the stator, so thats 3200 rpm, I think you'll need some ribs/bumps on the stator to allow it to be spun up to speed with the air line. Bit of a trade of with air resistance.

Could you use the tacho to find the max you can spin the stator at by finger?
The other thing to try is using the brass you have, increase the stator inertia to help the syncing process.
If you make a small flywheel about 12mm or larger out of brass rod, you could drill series of 2mm holes around the circumference to allow the air gun to work.
I think the holes will create only a small amount of drag compared to bumps.
Sorry for all the suggestions.

I brought home two harddisks today with the idea of stripping them for bearings, but it is not that easy. Although I have a set of security torque drivers, some of the hub screws are too tiny even for my set.
[edit]Hi Localjoe, its a old quantum 450Mb drive, I also have a new looking Seagate 40Gb barracuda. There will be more drives I can get at work, just need to keep checking.[/edit]

[Edit 2]alsetalokin is back on the Steorn forum in the last half hour, so he has not gone or been got by the MIBs (sounds painful!) , phew!!!, maybe he can give Sean some pointers now.[/edit 2]

Regards
Rob

[Localjoe]

Western digitals take apart fairly easy and completely dismount from the chassis. 
                                                                  Joe

[Aphiticus]

Hi Sean,

Looks great. 

Just a thought, i am of the opinion that the rotor magnets and the stator magnets when doing a reverse spin pulls the magnets toward each other thus forcing the rotation.  If this is true the rotor needs to be as light as possible and the stator needs to be heavier to pull the rotor.

Let me know what you think.

Adam

[ken_nyus]

cool stuff sean , starting my base plate today, although am tempted to plug a few of the new magnets into the old model i have..even though the measurements are wrong. The stator holders are they just brass shaft , friction fit to bearing and magnet?

Hi Craigy

I lathed down 6mm rod to around 3/16 one end and 3mm the other.
Then I mounted the magnet in the lathe and placed the Brass Rod in the lathe tailstock drill chuck. Then just gently squessed it in. They went in nice and square and a really tight fit.

I cut some 3mm brass tube I had to make the 6mm spacers and the bearings mounted in polycarbonate mounts either side.
 
(http://www.overunity.org.uk/ocpm/statorH3.jpg)

On the finished ones press fitted I just threaded the end so I could put a nut on the end and pull fit the shafts into the bearings.
(http://www.overunity.org.uk/ocpm/statorH4.jpg)

Good luck mate

Cheers

Sean.

So in this stator design, the bearings themselves do not rotate?

In Al's stator design, the bearings rotate with the magnets, and I believe they are ordinary (ie. magnetic steel) bearings.

May be significant.

[CLaNZeR]

So in this stator design, the bearings themselves do not rotate?

LOL yes they rotate or waste of time having the bearings.
The brass shafts sit inside of the bearings as the picture above shows.

[CLaNZeR]

Just a thought, i am of the opinion that the rotor magnets and the stator magnets when doing a reverse spin pulls the magnets toward each other thus forcing the rotation.  If this is true the rotor needs to be as light as possible and the stator needs to be heavier to pull the rotor.

Hi Adam.

Got various Rotors on the go and at the moment playing with the 6mm Thick Rotor below that has the 5mm rod magnets in it.
Simply by removing the spacers on the stator bearings it allows me to drop them level for the thinner rotors.

(http://www.overunity.org.uk/ocpm/statorH5.jpg)

Cheers

Sean.