Magnetic OU principle, You should really take a look at this !

[Yucca]

I did a test using neo mags with steel washers (of which may have become saturated in the strong magnetic field).  My test was just to see how much force there was between the washers.  To my suprise, there was very little.  The atrraction force of the neo's to the washers was much greater than the seperation force between the washers.  How does one intend to seperate the magnets from the washers if the attraction is so much greater?

Do not worry about the attraction force of the mags to the washers, yes it is alot greater than the washer seperation force but it does not matter, the magnets can be attached to a rigid frame so the force will not have an effect. Or if you do want to seperate the mags in a cyclic manner then the attraction forces will be symetrical and thus sum to zero over a complete in/out cycle. The small seperation force of the washers may be for free though.

[drsquires]

Pay attention to "Yucca". 
He understands how this principle works. 
He has it right. Good job Yucca.  Keep up the good work.

You guys are getting on the right track to fully understanding this principle
and it's significance.  FYI....I did careful measurements some time ago
on the forces for collapsed and expanded states on 1" diameter laminated
steel disks.  I verified that for the setup used the forces were equal to within
2%, which could be measurement error.  The expansion force measured was about 7.5lbs
in the collapsed state for 4 element stack and a "throw" of about one inch.
The magnets used were N45 NdFeB 1/4" thick with a steel flux return path for
maximum flux density in the gap.  The steel disks were M19 non-grain oriented
and the gap between the magnets was about   1.5 inch with the disks in between.
I used a digital scale to measure the force generated by the torque and then
factored in the change in moment arm or lever arm length.  Doing the math
gave nearly equal force (within 2%) for collapsed and expanded states.
This was a measure of the "cogging" forces to prove that they would integrate
to nearly zero since they would be essentially equal.  The torques will also
integrate to zero for entry and exit cogging.  The reason is that even though
the moment arm changes the angle of rotation also changes to keep the total
integrated torque equal for entry and exit cases.  Hence, the torques will also
integrate to a zero average leaving the expansion force to keep a motor running.
The attractive cogging forces or torques zero out of the result.  The resetting
of the stack must happen after the magnets have moved away.  Then all it
takes is to overcome their mass inertia to set them back to the starting point.
That makes a reciprocating system self-limiting for speed, which is a good thing.

Regards,
Dave Squires

[Butch]

Thanks Butch,
Have you built anything like this yourself?

Yes, but I want to have this a blind test for people doing it.
We also have done a test for the coil powered version using a scope.
Will post.
Regards,
Butch

[drsquires]

This is a response to "carbonc_cc" and his weak result.   

There is a strong correlation between the flux density in the gap between the magnets
and the saturation flux density in the ferrous elements used and their thickness.
Thin wafer-like or washer-like elements will create a relatively weak force.  Ferrites saturate at about 0.5 tesla
so it is not a good candidate for practical applications.

Use steels that saturate at 1.5 tesla or higher and you will more than triple the force.
Also the force occurs only on the end elements.  Any elements in between are "floaters" that
move to zero force positions.   Try thicker steel sections and stronger magnets with
keeper straps to maximize the flux density in the gap.   You will see weak forces
if you don't provide a flux return path for the magnets.  This has a huge effect.

I have shown that with large structures that you can generate hundreds of pounds of force
with strokes up to 6 inches or more.  Just imagine what can be done with an initial expansion
force of 600lbs!!  Keep going guys.  I want you to do your own
independent experimental verifications and come up with other ideas to put this to good use.

Regards,
Dave Squires

[AbbaRue]

So am I understanding this right?
The attractive force between the horseshoe magnet and washers equals out when using two or more units.
As one horseshoe magnet is brought close to the washers the magnetic attraction between the magnet
and the edge of the washers pulls the other horseshoe magnet away from the other set of washers.
Sort of like 2 elevators connected together so as one goes up the other goes down.
Then the energy from the separating washers is free.