Magnetic Shielding

[mbell]

I have a ton of hard drives laying around some old some new. Where i get this is from the end of the read write heads. There are two shields and the magnets are glued to the shields. The magnet will stick to the shield but will block any magnatism beyond that. It is hard to get the magnet away from the shield (because of the glue) and the magnets are very powerfull for their size. I am going to try this motor as I think it can be done useing the shields from the hard drive. http://www.fdp.nu/otherwheels/bartosz.asp?URL=bartosz.asp If you attach the shields to both magnets like it shows in the picture you should not get any attraction or repulsion until just before the magnets come face to face. The shields are in the new hard drives 3.5 inch and the are at the back end of the read write heads. They are like a half circle and the magnets are glued to them. The magnets are very easy to break so you have to be carefull if you want to save the magnets. I can post pictures of this if you need me to.

I think also if you use the hard drive as the turntable could you also get power out of the motor? This is what I am going to try as I think if you use the shields out of the hard drives and attach as shown in the picture it should work. (maybe) lol...

I hope this helps
Thanks
Mike

[Paul-R]

There is a concept of "shadowing" as distinct from "shielding" as discussed on:
http://tech.groups.yahoo.com/group/minatowheel/
Also, google for "parallel path" and check out "changing fields" on
http:www.fdp.nu
mu-metal has a reputation for shielding, although fields have a
way of leaking around the job.
Paul.

[gaby de wilde]

The easiest way is to look at simple wheel designs such as this that show shielding

http://www.fdp.nu/otherwheels/bartosz.asp?URL=bartosz.asp

Not saying it will work, but the logic is there.

Could you give us an example of where exactly on a magnetic motor would you be placing this insulating material? Where exactly is the spot that you are trying to insulate?

I look forward to hearing your results.

here is an idea using a shield I just drew up, the goal is to keep the shield in the exact center.


If this would run down one could wrap a coil around the shield and pulse that. With all the exotic shielding material you have I think this kind of contraption looks most interesting?

:-)

[rrintoul]

...
Also I would be interested in knowing how easy the material can be pulled away from a magnet when sliding it rather than pulling?
Also if you form a air gap between this material and the magnet, does it still shield?
...

Sean, this notion of sliding the shield rather than pulling directly away reminded me of an experiment I did.  The shield was as close to touching the magnet as possible, and it was very attracted to the neo.  When the shield covered the neo though, it almost perfectly turned it off.  You could put iron bolts right against the shield and there was very little noticeable attraction, even though the distance was only a few mm.  I found by using a strong elastic band to counter the shield's desire to cover the neo, I could create a close-to-equilibrium that made it quite easy to slide the shield on and off.  Here's a crude picture:



Reade

[stardelta]

Found this clip ..someone playing around with robbed hard drive mags and some type of shielding strip from a DC motor....

http://www.youtube.com/watch?v=yf2oybnz-vQ