Buddle Reciprocating PM

[prajna]

Hi guys,

Many years ago my Great Uncle, Allan Buddle, a superb inventor and 'rule of thumb' engineer, came up with an idea for perpetual motion but he was looking for something that would shield lines of magnetic flux.  Looking at the design I don't think that such shielding is necessary or perhaps mumetal could be used.  I didn't discover mumetal until after he died and he never built the machine.

I have puzzled on and off with the redesign of the machine from reciprocation into rotation but haven't come up with anything yet.  I thought it was perhaps time to put Uncle Allan's design out into the public domain so that some of you builders could have a go at prototyping it.

Here is how it works:  There is a rocker arm that controls two shields and is connected to an over-center lever. Triggering the lever is a sliding magnet that is repelled by fixed magnets.  In the diagram you can see that M1 (which is fixed) is repelling M3 (the sliding magnet).  When M3 travels to the right it hits the over-center lever and over-centers it so that the rocker arm reverses its orientation, thus raising the shield on the right and lowering the shield on the left.  Now M2 repells M3 and the opposite effect happens.

I hope you can work out from this description and the following diagram what the principle is.

[gyulasun]

Hi Prajna,

I am afraid your setup with mumetal "shield" will not likely to work.  Because mumetal (like normal soft iron) is nicely attracted by magnets and will get 'sticked' to either your  M1 or M2 or M3 magnets: you have to input further energy to 'liberate' mumetal from its attracted position. You may say here it is just a question of how strong magnets you use... but I do not think it is as simple as that (the stronger your magnets are the higher force is needed to liberate the shields).  And how do you think it would work without any shield? M3 would settle in the center position and stay there for ever. No?

A logical way to go ahead would be to use diamagnetic materials but without doing hands-on experiments it is hard to tell the outcome. Until recently Bismuth was known to be the best diamagnetic material but nowadays Pyrolytic Graphite, PG has been available and is even more diamagnetic, maybe you could try it in your setup.

See this link for PG:   http://sci-toys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html   

and also make sure you read over their Message Board here:

http://scitoys.com/board/messages/7/34.html?1046733751

especially questions Posted on Sunday, June 26, 2005 - 1:15 pm and till 6:09 pm. (especially answer to question 4)

So for you maybe it would be worth trying PG in your setup now armed with some more knowledge. Personally I tend to believe both PG 'shields' would settle in somewhere in a center position (because they are both being repelled according to the answer 4).

Let me show you another setup introduced a year ago on this Forum:
http://www.overunity.com/index.php/topic,302.15.html

This does the same reciprocal movement your M3 magnet is supposed to do but uses no shielding. You seem to invest a (probably small) mechanical input energy for keeping up the rotation (against friction and air resistance) and the author of that idea thinks he may get bigger output from the mechanical energy received from the inner pushed/pulled magnets.

Another good-looking idea from the same author I like is here also:
http://www.overunity.com/index.php/topic,309.0.html 

Regards
Gyula

[prajna]

Hi Gyula,

Thanks for a very interesting and worthwhile reply.  You make a very good point about mumetal - I suspected as much since mumetal works by attracting magnetic flux into itself.  And using diamagnetic materials is a great idea (dunno why it never occured to me since I am familiar with diamagnetism.)

Absolutely it would not work without a shield - what I meant was that it might work with a steel shield rather than 'something that shielded against magnetism' (which is what Uncle Allan was hoping to find.)

If it might work using a diamagnetic shield then it might also work with an opposing magnetic material - by, for instance, switching M1 and M2 alternately into and out of allignment rather than inserting a shield.

A PG shield would settle in the centre between M3 and M2 but my diagram was much simplified in order to simply convey the general principle.  Obviously the shields would be constrained in a channel so that they could only move up and down rather than being free to move laterally.

The links you gave were all very useful, particularly to M's designs.  He does not indicate how the rotation of his disc magnets would be achieved though.

I don't understand what you mean about investing input energy to continue the rotation - there is only reciprocation in this design and the only energy invested in continuing it is in flipping the overcenter lever.

Thanks again for your response.

[gyulasun]

Hi,

You wrote:  ...I don't understand what you mean about investing input energy to continue the rotation - there is only reciprocation in this design and the only energy invested in continuing it is in flipping the overcenter lever...

I meant not you but any person in general (sorry)  and I referred to not yours but that of M's design in the last but one link I gave, ok?

Gyula

[tbird]

Hi Prajna,

since this is in the "half baked" section, i thought this might be a consideration.

1.  turn m3 around to attraction mode.

2.  replace shields with magnets m4 & m5 in repulsion to both m1 and m3 (still in between like shields) on the one end and m2 and m3 on the other.

3.  change timing to insert m4 & m5 as m3 reaches closest point to m1 & m2 respectively.

your 1st thought might be "too much effort to push m4 & m5 in place".  i think not because when it's time to insert m4, m5 will help by wanting to come out of it's covering position and m4 will help m5 in the other half of the cycle.  also, with the mechanical arrangement, it should be possible to gain leverage.  ie m3 moves 2 times as far as m4 or m5.

the other thought i had was to replace m3 with a strongly attracted material.  the shield would reduce the attraction to that end and the material would be attracted to the other end until sheild was in place, then it would reverse again.

what do you think?

tbird