Working Magnetic Motor on you tube??

[ken_nyus]

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.

Sorry I know it is a minor point, but in Al's stator the outer ring of the bearing rotates, here the inner ring rotates.

I know it is a minor point, but these are magnetic steel bearings.

In any case good luck and have fun!

Wish I had a completed rig to play with!

[Craigy]

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

The idea is a fair one but the rotor in Al?s rig is approching 500 grams, and the general opinion is that the stator should be as light as posible. Using the brass shaft in this way separates the bearing from the stator magnet by some distance which hopefully will reduce bearing attraction drag , but having said that Al?s rig has the magnets plonked right on top of the bearings. If that plays a part i have no idea, just have to knock a few up to see,

[CLaNZeR]

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.

Have not turned the Tacho on the Stator magnets yet, will try that tomorrow, be interesting too see.
I actually have 2 tacho's here, so can monitor both at the same time

Could you use the tacho to find the max you can spin the stator at by finger?

The Big 20mm thick rotor max's out at around 400 RPM by hand.

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.

Will add them to the list LOL

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.

I have stripped down many a hard drive and if you Rip out the guts of the motor so there is no drag you can find some really loose ones. You will no way get the Wind Down times of using RC bearings Top and Bottom like Craigy and I use, so do not be too disapointed when you find this out.

Cheers

Sean.

[CLaNZeR]

Sorry I know it is a minor point, but in Al's stator the outer ring of the bearing rotates, here the inner ring rotates.

I know it is a minor point, but these are magnetic steel bearings.

Hi Ken

So is there more friction on the bearings spinning the outside ring or the inside ring?
Think about it

Cheers

Sean.

[ken_nyus]

Hi Ken

So is there more friction on the bearings spinning the outside ring or the inside ring?
Think about it

Cheers

Sean.

Hey Clanzer, I'm not thinking about the friction but the rotating (or not rotating) steel that is magnetic.

But please continue testing!