Roll on the 20th June

[shakman]

Okay, another hair-brained contraption. With a beer in one hand and a mouse in the other the creative juices really started to flow 

It's starting to look more and more like a Rube Goldberg machine, but it stays truer to Archer's Archurian Gate Key concept in that the metal rod transferring the magnetic properties to the iso-ferrite is disconnected from it before and after the iso-ferrite is activated. This should remove any issues with the rod retaining magnetic properties and transferring these to the iso-ferrite.

As per the previous example, the idea is to use leveraged non-magnetic arms to get the best bang-for-your-buck from the weight of the runner that has to depress the switch against the springs.

As always, pics to follow to give a better idea.

Again, I haven't looked to iron out any bugs outside of the switching mechanism so the Mayernik Array etc are just there to give an overview of the idea. It is by no means meant to be a running system illustrated, more just to get the switching mechanism concept across in hope someone with better building skills than myself can put it to use.

shakman

EDIT: Oops, I let time get away from me. I'm off to jam with the band then off to dinner after that so I won't be checking in for a few hours at least. The body clock is completely screwed right now so I might be MIA until tomorrow some time. Have fun kids!

[capthook]

Maybe what you should be looking for is "soft ferrite."

"There are basically two varieties of ferrite: soft and hard. This is not a tactile quality but rather a magnetic characteristic. 'Soft ferrite' does not retain significant magnetization whereas 'hard ferrite' magnetization is considered permanent. Fair-Rite ferrite materials are of the 'soft' variety."

Hi Oak - thanks so much for the links!

Guess we now have some confusion thrown into the mix.
One of the things when dealing with - well, anything (be it math, or physics or chemistry etc) is the need for proper terminology.  A circle is a circle ? not a square.

I would concur with you that it would/might appear that ?soft ferrite? would be the material of choice to use for this attempted application rather than ?isotropic ferrite?

From queues? video ? it appears he is actually using ?soft ferrite? where-as Quinns? video appears to be either a weak ceramic magnet, or actual ?isotropic ferrite? - (?)

Soft ferrite seems to be mostly for EMI suppression and various core-material applications and usually come in cylinder or disk form. (or "E" or "I" shapes)

So??.. what to use? What properties/size/form to get?

Thanks again for the info and hope you/others might provide/investigate further details.

- - -

Hard vs. Soft Ferrites:

Hard/Soft Ferrites ? Term relates to the coercive force(1) from remanence(2) to zero.  Hard ferrites are generally permanent magnets and can require up to 2000 oersted to demagnetize from remeanence to zero, where soft ferrites require small amounts of coercive force, typically from .05 to 4 oersted.


(1) coercive force: the magnetizing field strength required to bring the magnetic flux density of a magnetized material to zero

(2) remanence: the flux density remaining in a magnetic material when the applied magnetic field strength is reduced to zero

EDIT: P.S.

Hey shakman - aren't you in contact with Quinn? (or at least on good terms  ) ?
You (or someone) want to clarify with him EXACTLY what he's using?  tx
(and you may even want to suggest "soft ferrite" as it may actually be a better material for the application)

And oh.... with all the choices offered @ the Fairright site - I wouldn't even know where to begin...
(plus - "soft ferrite" blocks/rectangles don't seem to be the norm - I haven't seen any in that form)

[exxcomm0n]

K then...the 2nd test vid is processing.

Sorry about that, but I filmed me cleaning off the table and NOT the effect I found so I had to redo it.

This on is pretty short and to the point (a personal 1st), but it shows a roller jumping up into an array.........

..........but going backwards.

I swear it defies gravity and it is hard to see how I'd have gimmicked it up for this type of reaction.

I have no idea what use it is though yet, I have to sleep on it.

It's here:

http://www.youtube.com/v/D0M_1-5KJIg

...and now I can go beddy bye.

[Rusty_Springs]

Hi all
If you was a member of the yahoo minato group you could see through the messages section talk about magnetic current going back years but maybe this can give you a taste of what you may read if you went throught the old post.
http://tech.groups.yahoo.com/group/minatowheel/message/4374
Take Care All
Graham

[capthook]

As per the previous example, the idea is to use leveraged non-magnetic arms to get the best bang-for-your-buck from the weight of the runner that has to depress the switch against the springs.

tx for the pics - your CAD/drawings are always well done and easy to understand.

As I understand it per Archers page - the larger the contact area with the "ferrite" (more on that in a sec) the larger the "charge" imparted to it.  Thus - that contact point should be as large as possible.  The contact point with the "activating" magnet can remain small. (you've got that so far - just make the "ferrite" contact point like the same size as the "ferrite")

Now here's the main alteration:
Rather than have the "ferrite" contact move up and down - you should change the "pin" contact to the "activating" magnet move up and down (or left and right or whatever).  This way you will have a small force needed to activate/de-activate it rather than a large one. (overcoming the attraction of the pin/magnet rather than the ferrite/rod contact)

As to the "ferrite" - still learning and wondering and asking myself....

"Isotropic ferrite" is "hard" ferrite with "randomly orientated grains" that has been magnetized into a permanent magnet - just a weak one because it has no concentrated field.  It will maintain it's magnetic properties just like any permanent magnet.  It will stick to steel etc.
As to your question of what pole will appear when used with another magnet - my guess as to what happens is that it basically just channels the "charge" through it - so if you put a S face against it - a S field will come out the other side.
Now when "de-activated" it will still be a weak magnet and still attract steel etc.

Soft ferrite (as oak taught us) "does not retain significant magnetization".  But it's not a magnet itself - so it won't stick to steel.  But will become "a magnet" while engaged with another magnet for the duration of the proximity.(passing the same pole through like the iso)  But when "switched off" - it will have zero attraction to steel etc - no longer a magnet.

So - I guess the goal of the application would determine the choice of iso or soft?

You want it to turn on and then completely off: soft ferrite
You want it to get stronger and then weaker: isotropic ferrite
_ _ _ _

Still hoping for links/info/comments/on-line purchasing sites/education on isotropic ferrite and soft ferrite from anyone/everyone 

edit: hmmm - wondering which one would "channel" a larger percentage of the field?
Would soft ferrite be larger because it doesn't have to fight the random magnetism of isotropic acting like water through a filter? ? (I'm thinking yes)