Woodwards gearless clock

I looked at the clock some moons ago and tried to assemble the necessary materials. During this time I realised that one of the problems with it could be the transmission of the energy of the weights to the clock. The system used is one which involves a very narrow (small diameter) ‘transmission drum’ and keeping the drive cord tight enough to get enough friction to turn the ‘transmission drum’ (the area of the pivot where the cord is wrapped round). In the Woodward clock this tension is maintained by a ‘Jockey weight’. This Jockey weight acts against the ‘Main Drive’ weight so that if the Jockey weight is 1Kg and the Main drive weight is 5Kg, then there is only 4Kg of weigh to drive the clock. Make sure that the jocky weight pulley is very free running. Remember the old clock maker’s saying “if it rattles it will run!”

Hi

Have you looked at this site?

http://www.gadgetbuilder.com/GearlessClock/Gearless_Clock.html#Overview

He has lots of info about this clock

Keith

Leeds UK

Edited By ady on 23/05/2011 21:16:47

Edited By Chris Raynerd on 23/05/2011 22:27:21

Ah Chris I live in Hungary. Thanks to some oriental gentlemen who arrived with suitcases full of cash, metal in all forms is desperately thin on the ground. The stock holders now only have a small amount of structural steel for building. One small stock holder even sold his cut-off saw and all his racks. I have four projects which are part finished and on hold for metal.

So these days I do not even think about a new project until I have all the materials I may need locked away in a box for it.

Builder’s line, you may be able to get it in B & Q (if you can find it), but you will certainly find it in a builder’s merchant. It is the stuff ‘Brickies’ use to keep their level when lying bricks.

Perhaps a slightly random message but I was on here looking up my next project, John Parlows Skeleton clock when I came across this thread again.

I did complete the Gearless Clock: **LINK**

It seems like Mike Smith who started the thread is not an active user but just incase it does help anyone else, builders line was used and the V around the centre arbor made tighter so the line really "grips". It is a hell of a job to get running but does run very well once in motion!

On a separate note, I did not install any maintaining works! This was actually on suggestion or at least based on a comment by John aka GadgetBuilder. It takes about 30-40 seconds to fully "wind" the weight. If you simply hold onto the gated detent after a minute impulse has just passed, it gives you plenty of time to reset the weight! You have to engage the designed maintaining works so why bother when you can simply hold the detent!

Anyway... hope others try this clock. It is an amazing talking point!

Chris

Builders' Line: for those living in the UK; Screwfix product nos: 33964, 17261 & if fluorescent yelow and/or orange line appeals: 43630 & 71160.

An example: 17261 is here:

**LINK**

Chris, Really enjoyed looking at your clock and how you made it. It is a masterpiece. Your pictures are real crisp too.

Regards Bear..

Bear, thanks for your comment. I don`t know about a masterpiece but I`m certainly pleased with it! John - GadgetBuilder was a massive help and I pestered him via email no end throughout the build despite us being on opposite sides of the pond!

The clock is a real pain to get running. I expect in genuine honesty, I have watched it running, stopping and starting and trouble shooting for as many hours as it took to make the parts!

Niloch - good link. I just walked to my village hardware shop and they had some at 99p in white! It is fairly easy to get hold of and works infinately better for me than the fishing line called for in Wildings plans!

Another huge improvement that I forgot to mention is to add the doubled up pulley system - it gives a much longer run time!

Chris

I could start a new topic but I think this one is a better start.

Has anyone heard of the daisy wheel motion of Wilding's take on the Woodward clock being doubled to not only deliver hours from minutes but also minutes from seconds? I'm guessing it's theoretically possible but it may be impractiacally complicated.

Why am I asking? I'm wondering if a free pendulum could drive a second wheel and hence a minute and an hour hand via two concentric daisy wheels.

Thanks, Colin

Well, by definition it wouldn't be "free" if it did! I've also wondered about getting a higher level of reduction using the Daisywheel but it does feel like there would be a lot of friction to me, especially if it is being moved directly by the pendulum. I've concluded that for large reductions a better approach may be a pawl and count wheel.

There is an article in Horological Journal dated March 2003 2hich is by Derek Pratt, discussing his double daisy wheel mechanism on one of his sculptural clocks. There is a mention of an earlier article by Peter Hastins in the August 1979 issue, which is seen as a seminal article giving a comprehensive explanation of the daisy wheel and its many variations.

Here's a thought:

I have built several clocks using a daisy wheel arrangement for the drive to the hands. The basic dimensions were taken from a John Wilding design, and he, in turn, took the dimensions from a much earlier article.

When I chased up the source documents, I discovered that the daisy wheel is an inherently non-linear gearing. The time will be correct at some point, but will be too advanced at some intermediate times, and too retarded at others. The variation is dependent on the length of the anti-rotation stalk. I have a relatively long stalk, but the variation is still present.

I had to vary the dimensions of the daisy wheel itself, and then had to experiment with the pin spacing to get it all to work in a smaller size (the problem being that the as-designed size causes the wheel to obscure the winding square, in some positions of the eccentric cam). I couldn't get the dimensions to scale from the original theoretical explanation.

I also find that there is considerable scope for the weight of the hands to emphasize the clearance present in the daisy gearing.

So; an interesting, but deceptively simple solution to gearing the hands.

It does look pretty though, especially if you skeletonize the daisy wheel itself.

Marcus

Since receiving a copy of Woodward's "My Own Right Time" a week ago I have read the book from cover to cover, twice. Are there any other publications out there that cover Horology in the same detail? And are the majority of professional clock makers just skilled artisans that have no idea of the mathematics and physics of why they do things?

(I took 10 minutes carefully drafting the above paragraph but I still know I'm going to get flamed.)

Colin

Woodward wrote 'Woodward on Time' (WOT) which is excellent. However; I don't have 'My Own Right Time' (MORT) and suspect there is some overlap. WOT contains all of Woodward's articles, mostly published in the Horological Journal (monthly journal of the British Horological Journal). You will find much of interest at the level you seek, in the BHI Journal. Membership is not cheap, and the Journal does not have a huge number of pages (about 44 pages per issue), however; it is the place where you will find the most relevant information and articles, both practical and theoretical (reflecting the craft/theory balance typical of the way horology has developed.

The USA-based National Association of Watch and Clock Collectors (NAWCC) are worth a look, but once a member you may also opt into the Horological Science Newsletter, which will more than satisfy any desire you might have to delve into theory. I have found them to be an excellent and very helpful source.

There are lots of books dealing in a serious manner with particular aspects of clocks and watches; and some of those contain some theory. Many contain an in-depth review of a particular kind of clock, and some contain associated musing s on the theory. There are also lots which review types of clocks but do not delve into theory at all. All are expensive (a trait of horological publications of any size).

I believe the craft/theory balance is represented by Wilding and Woodward. John Wildings books are tremendous if you want to make a clock but are not bothered by theory; while Woodward never intended to be a maker, but was interested in the theory. Both have helped take us forward, and both are necessary components in the development of theory. That craft-then-theory path represents fairly typically the way horology has developed since its beginnings. I do believe, though, that the subtle underlying physics are just that - subtle- and most people looking at, or even repairing a clock or watch do not fully appreciate the influence of physics on the physical article, or the theory brought into action in a clock. That's not just true in horology, of course.

Woodward's most important practical work, based on theory, was W5, an impressively accurate clock completed in 1985, and detailed in MORT, I believe. WOT contains a chapter entitled 'A Fresh Look At W5' (first published in Horological Science Newsletter). There has been a lot of interest in that clock, and the underlying theory, and it has been subject to some important development, since the WOT book.

One or two other titles from my bookshelf:

The Science of Clocks and Watches (Rawlings)

Clock and Watch Escapements (Gazeley)

Wheel and Pinion Cutting in Horology (Wild)

One of the conundrums is that early pioneers understood, at least partially, what they were doing, but did not develop the physics or spread the knowledge. The craftsamn protected his own key knowledge, perhpas? That means later studies of the development of particular types of clocks represent an attempt to trace, reveal, and understand the early knowledge (a kind of knowledge archeology perhpas). So there are interesting strands of theory in many of the serious horological books on particlat clocks. Synchronome, by Miles, for example, survays the life and works of Synchronome and his clocks, but also contains clear and well expressed explanations of the theory and practical realisation on which the clocks are based. So a further list perhpas depends on the kind of clock in which you are interested.

I have those kinds of books on Synchronome, longcase, precision pendulum, chronomoeter, musical and electric clocks, which suggests I am interested in the pure mechanics and physics in all clocks and watches, which seems about right. That's the spot that Woodward hits. MORT and WOT being the top of that pile.

Marcus

Marcus,

Thanks for the early, long and considered reply; I've placed an order for The Science of Clocks and Watches.

My feeling is that most practicing horologists couldn't explain why the amplitude of a pendulum swing stabilises or know where to find out why it doesn't continue increasing until it hits the wooden case or seriously damages the escapement. The only book I've found that covers this aspect is MORT by Woodward. Compare this to the case of steam or internal combustion engines where most practioners are again following a recipe to get a working engine but there is an immense field of scientific/engineering theory underlying these engines which is relatively easily accessible.

So we end up with a craft that develops its own technical vocabulary (wheels versus gears for example) and abhors the new; are not ball bearings the work of the devil?

I must not say more as, at present, I am no more than an armchair clock designer with plans that have worked perfectly while they stay in my imagination.

Thanks again, Colin

Hi Colin

As a comparison it might be worth looking at William Smith's Gravity Arm Gearless clock which also uses the pin wheel and daisy mechanism. It has a seconds pawl off the pendulum which initiates the pin wheel pawl and hence the daisy. It is a pain to initially set up but once you've got your head round it, it keeps reasonable time.

While Bill described how to build many different styles of clocks, they were practical descriptions on how to make them rather than any heavy theory behind them. His other books and videos on practical workshop skills relating to clocks (and Morse keys) are an excellent grounding for anyone coming new to the hobby.

Alan