John Wilding 8 day Weight Driven Wall Clock

[Sam StonesParticipant @samstones42903]

During my morning walk, I realised that I forgot to add that – doubling the distance between the two clamped ends of the suspension spring makes it eight times less stiff.

I bow to Russell's knowledge because I have no experience with this mechanism.

I wonder however, if the spring was 20 thou 0.5mm thick, would it still work?

I wouldn't know, but my guess is that it wouldn't.

Regards,

Sam

[Dick HParticipant @dickh]

Reducto ad absurdum. If the spring is too stiff the resonant frequency depends on the spring not the length of the pendulum. The suspension spring should just store enough energy to keep it going, if too stiff it will kill the oscillation, the movement of the escape wheel will be countered by the stiffness of the spring it will not disengage. Too stiff and you can fiddle with the length of the pendulum as much as you like, you can never adjust it to keep time, the spring dominates gravity as a restoring force. Both books say 0.006" for the thickness, as far as I can tell mine is running with a 0.004" (0.1mm) spring, I tried 0.006" but had problems (perhaps for other reasons). In any case depending on the heat treatment of a steel the modulus should vary anyway. Regards, Dick.

[Sam StonesParticipant @samstones42903]

Yep, virgin on the ridiculous Dick H,

I beg to differ with regards to the changes resulting from the heat treatment of steel.

A higher tensile strength yes, but the modulus stays virtually the same.

And clearly, a four thou (0.1mm) thickness will even more approach a knife edge suspension while a six thou (0.15mm) thickness will be about 3.4 times stiffer than a four thou (0.1mm) spring. Similarly, the thinner the spring the less energy it will store.

Aren't we now talking about the method of suspension or am I now out of my depth?

Regards,

Sam (aka Dennis)

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Sam Stones on 08/11/2017 23:14:22:Aren't we now talking about the method of suspension

Yes. Although in the extreme it won't work I doubt that going from 6 to 8 thou will make any difference. My regulator clock runs O.K. using nominal 6 thou suspension spring from the same supplier but I have never measured it. Of course the pendulum is probably a bit heavier.

You can measure the losses in the pendulum and suspension easily by letting it swing freely (remove the crutch) and count the number of complete swings for its amplitude to fall to half the initial value. The number is very high so it's easier to time it and divide the time in seconds by two for a "seconds pendulum".

The Q factor is then given by: number of cycles times 4.53. I would expect the Q to be between 8 and 10 thousand.

Russell

[Martin KyteParticipant @martinkyte99762]

Posted by Jim C on 08/11/2017 17:16:58:

It just runs out of steam and does not appear to give any kick to the pendulum. Not sure where this kick is meant to come from ???

Take a look at this animation

https://www.google.co.uk/search?q=anchor+escapement+animation&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjnpaW2jrHXAhXQF-wKHWXUDswQsAQIOA&biw=1890&bih=898#imgrc=DLIhVcAer0tDsM:

You will see that the escape wheel puts pressure on the curved faces of the anchor escapement which impulses th ependulum. This is the power required to maintain the swing.

With an anchor escapement you will see an amount of 'drop'. This is the reverse motion of the escape wheel when the pallets first touch the escape wheel and occur just before the pendulum reaches the end of its swing at either side. If you consider a situation where the reverse movement is equal to the forward movement then mo power would be extracted from the train. For max power to be delivered to the pendulum the reverse movement or drop should be at a minimum and is adjusted by setting the depth of engagement of the escape wheel with the pallets. On this clock there is an eccentric bush to do just that.

I apologise if someone else has already said all this as I have not had time to trawl through every post.

Anyhow do study the animation and get fixed in your head exactly what is gong on.

regards Martin

[Martin KyteParticipant @martinkyte99762]

Sorry I should have linked to the animation

**LINK**

regards Martin

[Sam StonesParticipant @samstones42903]

Because ‘I naw nawthing’ I suppose I should keep my nose out of this … but … presumably, there will be a great deal of practical and theoretical information on this type of pendulum suspension?

Never having studied what is actually happening, it wasn’t until I noticed the length of the spring (in Stephen Benson’s photographs) that I realised how little of the spring is actually involved in bending.

It is clear that most of the length of the spring will be in pure tension resulting from the (relatively) significant weight of the pendulum.

However, I can’t get my head around how much of the spring (at its top end) will be in pure bending. This then leads (me) on to Russell’s statement in that he doubts … going from 6 to 8 thou will make any difference.

From my vantage point, increasing the spring thickness will (initially) bring into play more spring length.

That’s my six penn’orth, allowing for inflammation.

Regards,

Sam

[Sam StonesParticipant @samstones42903]

Hi Dick ,

Please see your 'Messages IN' box.

Regards,

Sam

[Tom SeniorParticipant @tomsenior17505]

Thanks for all the comments and suggestions on this forum.

I have just succeeded in getting my own version of John Wilding's 8 day clock running.

I have taken many photos during the process and have tried to summarise the process on my blog. If you're keen to see, or have any questions, you can follow this link and check it out.

https://tomsenior.wixsite.com/8day

Thanks.

[Damian GTParticipant @damiangt78472]

Hi All, Newbie here – and first post. I am closing in on finishing my eight day clock. I can't see anywhere in the book (first version) where to find the length of pendulum rod. Any help appreciated. BTW I have found all of the posts above very helpful indeed as I have progressed with my clock.

Thanks,

Damian.

[Marcus BowmanParticipant @marcusbowman28936]

Nice website/blog, Tom Senior. Useful and informative photos. Thanks.

Marcus

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Marcus Bowman on 05/04/2021 18:41:58:

Nice website/blog, Tom Senior. Useful and informative photos. Thanks.

Marcus

.

+1 from me

Just one small suggestion …

perhaps add a short obituary note to your post on John Wilding

MichaelG.

.

Ref. https://www.model-engineer.co.uk/forums/postings.asp?th=171248

Edited By Michael Gilligan on 05/04/2021 18:59:25

[Zachary RohrerParticipant @zacharyrohrer26143]

The information in this forum has been very helpful so far. I am building a version of this clock from the old book, and have had some trouble getting my ideas straight, probably because this is my first clock. Has anyone done a seconds hand? I see reference to this as an option in the newer version of the book, but I wasn't able to get a copy when I was looking to start the project.

I have made the great wheel and steel pinions for the train, but have yet to plant the train, Currently I'm looking over options and making plans before I start drilling holes in the plates.

[WH GSParticipant @whgs19140]

Hi all,

I am new to making clocks and have been struggling to identify some of the things I would need. Would anyone know what diameter gut I would have to get for the barrel?

Thanks

[roy entwistleParticipant @royentwistle24699]

WH GS 1.4 mm or about 40lb breaking strain fishing line

Roy

Edited By roy entwistle on 19/11/2021 22:22:41

[WH GSParticipant @whgs19140]

Roy,

Thank you for the advice.

[Dick HParticipant @dickh]

To Zachary Rohrer,

The second hand pushes on to a tapered extension of the arbor that carries the escape wheel. You can see it in my photo from 09.06.2017 and Stephen Benson´s photos from 30.12.2016. I built my clock with steel pinions according to the second spiral bound book from ritetime publications. I also have the red jacketed first book which uses lantern pinions. The layout and other details of mechanism in the two books are subtly different so beware.

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by WH GS on 19/11/2021 11:22:25:

I am new to making clocks and have been struggling to identify some of the things I would need. Would anyone know what diameter gut I would have to get for the barrel?

Personally I wouldn't use fishing line as it's not intended for a continuous load. 1.4 mm longcase clock synthetic gut is rated for 39 lb safe working load and the breaking strain is about five times that. If it breaks with the weight near the top the weight can do a lot of damage.

Meadows and Passmoor used to sell it, don't know if they still do.

Russell

[Clock polisherParticipant @clockpolisher]

I buy most of my clock materials from John Wardle Clocks.

I don't have any affinity or other involvement with them, I just find they give good service.

regards,

David

[Martin KyteParticipant @martinkyte99762]

My Wilding 8 Day has a 1.5mm steel line. Cousins Material House do lines under Lines,Ropes and Cords.

**LINK**

No issues with strength. The clock weight is shared between the 2 lines of the drop.

You can use Gut, 1.4mm Perlon would suit.

regards Martin

[duncan webster 1Participant @duncanwebster1]

Speaking from complete ignorance, but you can get fishing wire pike. Up to 40 lb breaking strength.

[Martin KyteParticipant @martinkyte99762]

I don't doubt it Duncan. The Wilding clock doesn't need more than 10lbs on 2 lines.

regards Martin

[Sam StonesParticipant @samstones42903]

This happened to the 80lb fishing line I was goaded into using. Only our dog was there at the time it broke, but I imagine from a near full wind, it must have got off with quite a din.

BTW, from my background in plastics, I should have known it could happen (creep before failure).

Here's the result of a three-year stretch –

I replaced it with steel, generously supplied by a local antique clock repairer east of Melbourne.

PS – I wasn't the only one that got the winding direction wrong. It turned out to be how the barrel arbor had been drawn, and my lack of knowledge.

The knots on the ends are a mess, and will stay that way.

Sam

[Sam StonesParticipant @samstones42903]

Adding to the above, this was a paragraph I wrote when I described building John Stevens' skeleton clock. (refer Model Engineer #4526 – Jan/Feb 2016)

To transfer the power from the barrel to the fusee I had used braided plastic fishing line. The (yellow) fishing line was rated as having a breaking strength of 80 lb. My fairly rough measurements had suggested that the main spring was exerting a tension in the line equivalent to a weight of about 10 kg (22 lb). There was plenty of strength to spare, or so I thought.

I trust this helps.

Sam

[WH GSParticipant @whgs19140]

Hi,

How did everyone make their click spring ? Did you start off with a normal brass sheet only?

kind regards

WH

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