Electromagnetic Properties

[Michael GilliganParticipant @michaelgilligan61133]

dave8

Page126 of the ‘Artificer’ series gives the weight of the [presumably original] balance wheel.

MichaelG.

[david bennett 8Participant @davidbennett8]

Thanks. The weight of the balance is given as 12 ozs. However I was searching for

the total weight of the reciprocating assembly,  including the iron bars and the coil.It must be quite massive!

I wondered how the balance pivots coped, and how thick an oil was needed.

dave8

[david bennett 8Participant @davidbennett8]

P.S to the above. Maybe I mis-read it, but 12ozs could be the weight of the complete balance system.

dave8

[John HaineParticipant @johnhaine32865]

The pivots are actually weird ball bearings  and from what I recall seeing a number of these clocks at an AHS meeting they run in a sort of oil bath.

[david bennett 8]

On david bennett 8 Said:

P.S to the above. Maybe I mis-read it, but 12ozs could be the weight of the complete balance system.

dave8

That’s why I gave you the reference instead of just a number

… interpretation is then down to you, not me 🙂

MichaelG.

[John Haine]

On John Haine Said:

The pivots are actually weird ball bearings  and from what I recall seeing a number of these clocks at an AHS meeting they run in a sort of oil bath.

Described by ‘Artificer’ in some detail [with options!] commencing on page311

MichaelG.

.

Note: __ the numerous options presented in this series are what prompted me to question its validity as a copy of the original. … The discussion has moved-on quite a lot from the original post, and if we are now digging deeper, then I suggest that point needs to be appreciated.

[Michael GilliganParticipant @michaelgilligan61133]

Is there a Canadian in the house ?

The Espacenet copy that I linked earlier is extremely poor … but I have found reference here:

https://www.ic.gc.ca/opic-cipo/cpd/eng/patent/100982/summary.html?type=number_search&tabs1Index=tabs1_1

Still struggling to find it as a download though

I probably just need Coffee … but assistance from someone familiar with that site would be very welcome.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Too late to edit my earlier post:

This page includes the best photos I have yet found of the bearings:

https://www.sellingantiques.co.uk/660843/eureka-electric-mantel-timepiece/

MichaelG.

[Michael Gilligan]

On Michael Gilligan Said:

On John Haine Said:

The pivots are actually weird ball bearings  and from what I recall seeing a number of these clocks at an AHS meeting they run in a sort of oil bath.

Described by ‘Artificer’ in some detail [with options!] commencing on page311

MichaelG.

.

Note: __ the numerous options presented in this series are what prompted me to question its validity as a copy of the original. … The discussion has moved-on quite a lot from the original post, and if we are now digging deeper, then I suggest that point needs to be appreciated.

Thanks for clarifying. I must admit that my only interest in this is as a sceptic of the design, though the slow-running balance is attractive. For this, a very large inertia seems inevitable, as does bearing problems. (Michael G – this is a reply to your reponse re weight of balance I seem to have the wrong quote )

dave8

[david bennett 8]

On david bennett 8 Said:

Thanks for clarifying. I must admit that my only interest in this is as a sceptic of the design, though the slow-running balance is attractive. For this, a very large inertia seems inevitable, as does bearing problems. (Michael G – this is a reply to your reponse re weight of balance I seem to have the wrong quote )

dave8

No problem, dave8 … It’s infuriatingly easy to to do the quoting wrong !

Someone decided to put the links at the top of posts, instead of leaving them where they were.

[ such is ‘progress’ I suppose ]

MichaelG.

 

[Peter Cook 6Participant @petercook6]

Couple of better images of Eureka bearings. Some are three balls as on the top image, some only have two balls as and a plate which retains them in the correct position as in the lower. The arbour is central to the housing and rides on the lower two balls.

They are fascinating clocks to watch (and work on). I have a couple a short (the two ball) movement which has the balance wheel behind the dial, and a tall (the three ball) movement with the balance wheel below the dial. The latter is very similar to the one Michael linked to.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Peter … very interesting

MichaelG.

[david bennett 8Participant @davidbennett8]

I have just realised what these slow moving balances remind me of – verge lantern clock balance wheels!

More thought needed

dave8

[Peter Cook 6Participant @petercook6]

A slightly pedantic point. The Eureka big wheel is not a balance wheel. A true balance wheel is designed as a harmonic oscillator. The Eureka wheel not only controls the timekeeping, but also transfers power (as kinetic energy) from the magnetic impulse to drive the motion work.

More detail at NAWCC post

[John HaineParticipant @johnhaine32865]

I guess a Synchronome pendulum is therefore not a pendulum by similar logic?

[John Haine]

On John Haine Said:

I guess a Synchronome pendulum is therefore not a pendulum by similar logic?

John I don’t own a Synchronome, so am only speaking  from reading, but I would argue that it is a pendulum, in that the only “interference” with the pendulum oscillation is the mechanism that delivers the maintaining impulse to overcome friction and air resistance. That is no different in principle from the connection between the escapement pallets and escape wheel on a mechanical clock.

Driving the contacts that actuate the slave dials (the motion work!) is a separate process, and the power needed to do so is provided directly from the battery. The pendulum simply times the delivery of that power in the same way as the escapement of a mechanical clock times the “escape”  of power from the great wheel to the motion work.

In a Eureka the power needed to drive the motion work and hands is added to the big wheel when it is impulsed, and then removed by a cam and follower mechanism at a later stage of the rotation. So all the power needed to drive the motion work is transferred through the oscillator, not simply timed by it. Hence my argument that it’s not a balance wheel in the sense that most horologists would understand the term.

[John HaineParticipant @johnhaine32865]

In the @Nome there’s a pawl on the pendulum that pulls a count wheel one tooth at a time, that releases the gravity arm to impulse the pendulum once every 30s.  Other EM clocks (e.g. Kundo, Kienzl) have the count wheel driving the hands.  The Eureka construction articles describe it as a balance wheel as does a number of other documents on the clockdoc site.  I think most horologists seeing a Eureka would call it a balance wheel.

[david bennett 8Participant @davidbennett8]

Or a Hipp?

dave8

[david bennett 8Participant @davidbennett8]

It is described as a “balance wheel” in the original patent.

dave8

[Michael GilliganParticipant @michaelgilligan61133]

I don’t personally want to get involved in this philosophical discussion … especially as the 1906 patent offers alternative arrangements in the area of drive to the train … but am happy to be in the audience !

My own mission is to track-down a better version of the patent.

The illustrations in the Canadian one are simply not good enough … important information having been lost in the copying process [see particularly the bearing details]

This useful page gives me some hope:

https://clockdoc.org/Default.aspx?aid=48

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

‘ere we go …

https://www.model-engineer.co.uk/wp-content/uploads/sites/4/mediapress/members/79913/678121/US853648.pdf

MichaelG.

[Andrew Johnston]

On Andrew Johnston Said:

gave up when he said B equals H. They are not the same thing

To be fair to Norman, he does go on to say the relationship between B and H is complicated in the next slide.

[jaCK HobsonParticipant @jackhobson50760]

Re Wrought Iron… I believe there are two sorts: Old ‘wrought’ is manipulated by heating, folding, forging an iron bloom to get slag and impurities out of an iron bloom. Puddled wrought iron is mass produced from cast iron (pig iron) and stirred while molten to burn off the carbon but still keeps the silica (slag inclusions). I guess old wrought has less silica inclusions and is a better quality to work with.

I don’t think you can ‘hand forge’ cast iron. It will disintegrate. Cast Iron needs puddling to get it to puddled wrought iron. So I believe the comments in the vid are confusing the types of wrought iron.

My guess is that old, quality, complicated-in-design tools might be a source of older wrought – for instance I have a broken, old, blacksmith leg vice which I would guess is the good stuff. Heating and folding etc only gets rid of some impurities. Some ore will not lend itself to repeated manipulation. A friend of mine has a theory that the pattern-welded swords were partly a demonstration of the quality of the iron; poor iron, with unwanted impurities, will not stand up to the twisting or heavy manipulation required in pattern welding.

Big amounts of iron, in simple shapes, are more likely puddled – including railings, anchor chains etc.

I would guess Puddled iron would be more ‘stringy’. So looking for stringiness as a sign of pure iron… probably not a good test.

But… this just reminds me of my experience with knife-making… and my conclusion that if you are going to invest time in something then start with ‘known’ materials. i.e. get newly supplied iron from a reputable source.

[Michael Gilligan]

On Michael Gilligan Said:

My own mission is to track-down a better version of the patent.

Michael,

In the appendices of Alan Shenton’s book on the Eureka  Clock there are copies of UK patent 14,1614; Date of Application 26th June 1906 – Accepted 14th February 1907, and something called Complete Specification No 4711 Date of Application 24th Feb 1911 – Accepted, 14th May 1911. The latter seems to be the design for a more conventional clock rewound by an electric motor. I am not sure of the copyright situation as both appear to have been typeset rather than photocopied from the original.

My “philosophical” comments on the balance wheel were made in the light of a discussion with Bryan Mumford back in 2003/4 concerning the purpose of the screws on the edge of the balance wheel. Both my clocks have larger screws of very different weights(eg. 4g & 6g), as do the ones he has worked on, and it is possible to make a significant difference to the rate (plus or minus 2.5 hours per day) by swapping heavy for light in pairs round the wheel.

Bryan and I concluded that the wheel was not designed to be poised in the same way as a true balance wheel, but the effect on rate was a deliberate design. We surmised that the manufacturers would probably have rated production clocks by setting up a standard pattern of heavy and light screws, run the clocks for a given period, then there would have been a standard table of adjustment (e.g. if 5 minutes fast swap no 3 screw for a lighter one etc, etc, etc). This would have allowed them to employ semi-skilled production workers rather than skilled clockmakers to set up the clocks.

As far as I know none of the patent applications go into that much detail.

[Michael GilliganParticipant @michaelgilligan61133]

Many thanks for the references, Peter

Unfortunately, I don’t have access to Alan Shenton’s book … but I am reasonably satisfied with the copy of the US patent that I put in my Documents Gallery this morning.

As regards the philosophical discussion … the ‘truth’ isn’t of any particular interest to me, but I shall be happy to watch you and John debating the point.

My own main interest has been to prove my point that the series by ‘Artificer’ simply cannot be considered the definitive copy of the EUREKA … because both it and the patent contain so many options.

For example: You have two different bearing arrangements in your clocks, and neither of them much resembles what is shown in the patent.

Although I started this Topic with the intention of prompting discussion about Electromagnetic investigations, it has taken some very interesting side-steps … and long may that continue !

MichaelG.

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