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Hi Raj Thanks for getting in touch. I use a commercial program "Gear Generator" (there are others) to draw the wheels with the right number of teeth and pitch diameter I want. I then use a laser cutter to cut them out. Gears can also be cut by hand with a band saw after gluing an image of the gear on the wood. I usually use 3mm laser ply or veneered ply as it suits my laser cutter but sometimes I use MDF for prototypes. Better wood can be used if you want to afford it. Fine sanding of the teeth of the gears after cutting reduces friction considerably. Best of luck Nigel

Did you ignore that this is a reproduction of a 1759 design by the same guy who eventually made the marine chronometer?

Hi Steven, I agree that John Harrison was not awarded the prize as such, and you are right in saying that it was a very complicated situation with Maskelyne and his competing lunar system. In my defence, for simplicity, I reiterated the commonly held view that he did win the prize. Over the years he did receive monies from the Board to pursue his work but it took a petition to the King for the board to benevolently grant him a final payment that brought his total take up to the £20,000 mark. The actual prize has never been won. As regards Masklylene and his lunar system it did work and tables for the computation of longitude were published and used annually from 1766 to 1906. It was a viable but more complicated and time consuming method for determining longitude. The complete story of the trials, tribulation and success of John Harrisons life , against a background of skulduggery, personal feuds and machinations are admirably recorded in Dava Sobel's book Longitude.

@@MrParamount3 Then someone needs to explain this moon thing to me cause I don’t see how it can work.

In simple terms you measure the angular distance between the moon and a star or the sun and then use pre calculated tables of the moon's position to find the time at Greenwich. You then need to make a further observation to find local time. The difference between the two times gives you longitude. Wikipedia gives a good account of the process. Search lunar distance(navigation)@@stevendebettencourt7651

Hi. Thanks for question. If you look at my blog www.woodenclockspot.blogspot.com you will find diagrams and a description of the workings of an Earnshaw escapement. Suffice it to say here that some energy is taken from the balance wheel during unlocking but this and more is put back as the escape wheel impulses the balance wheel. This energy comes from the driving train and mainspring. The balance wheel apart from being a constant oscillator is also an oscillating mass and thus an energy store for difficult times when it has to do some work such as unlocking. I hope this helps.

@@MrParamount3 ah ha! i didn't see the impulse pallet on the roller table. that makes a ton more sense. without that part i imagined that it would stop pretty quickly. thanks!

I can confidently say that’s the only wooden hairspring I’ve seen with a Breguet overcoil

@@Mars-zgblbl Ha!

Absolutely correct

It's not a clock, it's an escapement.

Hi. You are absolutely right. It is such an elegant solution. It is interesting to note that some of the rules for meshing gears are bent, but it works.

@@MrParamount3 Thanks! Yeah its brilliant.. I have questions.. any books or the like (web sites etc) you could recommend for (wooden) clock making? fairly new to horology, came to it from interest in sundials and astronomy.. considering getting into wooden clock making, particularly interested in perpetual calendar.. I notice from your blog you don't really have plans to share (would love to see plans for this mechanism.. what are the 'rules' and which were bent)?

@@mirrormill Hi. I get all my inspiration from searching the web and reverse engineering to suit wood from photographs. You could try 'Brian Laws wooden clocks' or 'Clayton Boyer' who have comprehensive designs. I don't distribute plans because my drawings are an absolute mess and would require far too much effort to make them sensible to other people. Normally clock gears are made to quite tight tolerances on fixed centres. In this instance he employs one of the pinions driving two wheels, one of which varies its distance from the pinion, but he gets away with it. As regarding building one There is more information on my blog than I started out with when I first built it. You should be able to reverse engineer it from the photographs and description.

@@MrParamount3 Ah i get what you mean about the eccentric 29 Feb wheel. I can see how that would not be a regular solution.. too eccentric and it wouldn't mesh.. what a Maverick! Was thinking about starting on one of Boyer's starter clocks.. I have to get euip first thoough.. before that I have an idea for a mobile variation on a Bifilar sundial which can be adjusted to correct for EoT and DST.. cab be made from card and paper.. will explain if curious..

Laser cut 3mm plywood

Because I am not trained in fine engineering, haven't got the equipment, but I can use a saw

Now this is not noting, This a lot off work to make.

Hi. The answer to your question is complicated, but here goes. The aim is to keep the balance wheel, which is the timing part of the watch, swinging regularly and invariably which will give accuracy and good timekeeping.. Remember this was the 18th century and they didn't have the modern materials we had. They were groping towards solutions. The big mainspring has a lot of power when fully wound and much less when it is wound down. The balance wheel would see variable force which is not ideal. In this remontoire a small spring is wound by the mainspring every 7.5 seconds and it is this spring that powers the balance giving regular and almost constant torque. As long as the mainspring can wind the remontoire spring the watch will work with constant force. My blog www.woodenclockspot.blogspot.com has a little more detail on this point.

@@MrParamount3 Thanks so much for that explanation. That was actually very clever. We moderns tend to look down at the past, (atomic clocks, quartz, etc) but early achievements like this should be recognized and celebrated. Cheers.

@@MrParamount3 Thank you, brilliant design

Thank you Tommy, prise indeed. I guess you have seen my H1 model video

Hi Joseph You are correct, mine does just that when the motive power is removed. Harrison recognised that and added a lever operated by the fusee that applied a brake to the balance wheel rim half an hour before the main spring ran out. Thus the remontoire spring was left in a fully wound state. It should never get that far when wound regularly and would have been a skilled job to pre tension the remontoire spring if it did run down. My model has has not got that sophistication but has got a manual brake on the balance wheel. My remontoire spring needs 3 eights of a turn which equals 3 full rotations of the 5 th wheel to pretension it. Hope this helps.

@@MrParamount3 Thank you for that. I was curious to see if Harrison had come up with a different solution. It sounds like both he and Daniels (who made a couple of watches with a remontoire) used effectively the same solution.

Some of the best horological geekout material in these two comments. I wish I understood the content better though.

Good plan. Done

@@MrParamount3 Thanks!

Thank you for looking at it

The answer is that technology moved on very rapidly. Within a few tens of years they developed better escapements for chronometers, see Earnshaw spring detent escapement, and worked out how to manage balance hairsprings so that the differences in frequency between large and small swings of the balance were much reduced. The remontoire was thus banished to history for chronometers. The fusee was still retained. Together with temperature compensation at the balance the chronometer then stayed essentially unchanged for 200 years until quartz took over. Harrison's work was effectively a magnificent dead end, the important bit being that he proved a chronometer could keep accurate time at sea and that he inspired others to produce chronometers better and cheaper, leading to mass adoption.

ofc this is not the best solution by today's standard. This was made in 1759.

Remontoirs are actually very effective especially when you are constrained with space in watches and cant use a fusee or where you have a escapement with larger lift angles like any lever escapement (swiss lever etc like the one shown). There isnt much “wasted” energy in a modern remontoir and that isnt really an issue you are concerned with as the gear trains only job now is to charge that spring. There were some very acurate competition watches made with remontoirs and derek pratt made some of the most stunning toubillon remontoirs that are really worth checking out

Great answer and lovely to Derek's name being mentioned. @@felixarbable

It doesn't matter that energy is 'wasted'. All the mainspring has to do is re-wind the remontoire. Again it doesn't matter that the remointoire may not be the best means of achieving constant force, what is worth considering here is the spring that drives the escapement is re-wound every 7 1/2 seconds so escapement error effectively becomes invisible. Once you have Arnold's terminal curves on the balance spring and isochronism is approached, the remontoire can be done away with.

Hi Mahmoud, Thanks for spotting the error. The answer is that I explained it poorly. I should have said the 5 long teeth are for those months with less than 31 days which is four + February. I go into greater detail in my blog at www.woodenclockspot.blogspot.com. I still find it a confusing device to bend my head round. Thanks again.

@@MrParamount3 Ok thank you

@@MrParamount3 WOW a Fantastic blog you got there.