Mild Steel as material for gears

[Mogens KildeParticipant @mogenskilde92996]

Hello Folks

 

As I’m having to have a break from making Steam Engines, I’m considering a project of making a clock.

 

Mostly (allways) I see that the gears is made from brass, why is steel not used for clocks, is it estetic reason or will it be a problem to use steel ?

 

regards

Mogens 

[Mogens KildeParticipant @mogenskilde92996]

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by Mogens Kilde on 12/12/2010 15:05:58:

Hello Folks

 

As I’m having to have a break from making Steam Engines, I’m considering a project of making a clock.

 

Mostly (allways) I see that the gears is made from brass, why is steel not used for clocks, is it estetic reason or will it be a problem to use steel ?

 

regards

Mogens 

 Mogens –

 

The usual combination seems to be engraving (leaded) brass for the wheels and steel for the pinions.  I don’t know of any particularly good reason for it other than it seems to work well & the use of brass for the wheels means they are rather easier to cut, cross out, etc.. I doubt if there is any particular reason why you shouldn’t use steel.

 

Regards,

Tony

[NJHParticipant @njh]

Hi Morgens

 

Well not always  – I’ve seen quite a few mass produced  “cheap & nasty” clocks with steel wheels  (not gears in clocks). The usual way is to have brass wheels meshing with steel pinions. The wheels need to have their mass reduced and this is achieved by “crossing out ” – removing material from the blank disc such that there is a “hub” from which will radiate a number of “spokes” supporting the “rim” on which the teeth  are cut. This material is traditionally removed with a piercing saw and finished with files and a burnisher. From a practical point of view this is much easier to do on brass than steel I think.  ( Note though that Richard Parsons, a regular contributor to these threads, has an article in the current issue of ME on crossing out using a rotary table on the mill. I intend to try it)   The other joy of clock making is working with brass – I find it very satisfying. Bear in mind that you will want to make an aesthetically pleasing job here as you, your family, your mates and any critical relatives will all want to look at it and admire ( or criticize ) whereas they probably treat your superb Loco, Stationary Engine, Tool & Cutter Grinder etc. with indifference! Do you have any idea which clock you may tackle? 

 

Regards

 

Norman 

 

PS  Sorry about the change of text size during this post – Don’t know what happened there and I’ve not been able to change it. 

 

 

[Mogens KildeParticipant @mogenskilde92996]

Hello Tony and Norman

 

Thank you for your reply.

 

I’m working on the 15 day skeleton clock article by John Parslow,  from the ME issue 4233 and forward.

 

I would however like to make a clock a little lower in overall height, but I’m a little unsure about the pendullum. I suppose the beat is proportional to the lenght, but if the pendullum is going faster, like 288 beats, will it be impossible to make the escape mechanism work ?  

 

I getting hold of some books on the subject of clock making, but I have also found some suggestion on books in this forum, so maybe I will have check out these also.

 

 Mogens

Edited By Mogens Kilde on 12/12/2010 19:09:09

[Tony JeffreeParticipant @tonyjeffree56510]

Mogens –

 

If you shorten the length of the pendulum, the clock absolutely will not keep time (it will run fast), unless you also re-design the clock train – either change the number of teeth on the escape wheel (which would probably also entail re-designing the rest of the escapement to fit) or changing the number of teeth of the wheels in the train to suit. Either way, I wouldn’t advise attempting that before you have a bit more clock making experience/knowledge.

 

Regards,

Tony

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

Hej Mogens, you can search after the book in Denmark there you live:  Haandbog for Urmagere, Kbh. 1948, 3 bind. The antique book shop some time has the book in store. The books are well written for all watch makers.

 

Steel has been used in larger clocks, to example in church, tower due cost of material since brass is not cheap in too large gearwheel.

 

 

[Ian S CParticipant @iansc]

Jens, possibly the gears in those larger clocks are made of cast iron, maybe running on pinions made of steel, this would run better than steel on steel.  thats also the mechanical reason for using brass.

  If you disassemble an old clockwork toy, or ceap clock with pressed steel gears, you will find the pinion is badly warn with a groove the eventually won’t mesh.

  I have no clock making expiriance, but if I were to make one with steel  gears, I think I would make the larger wheel from mild/ medium carbon steel, and the pinion from silver steel, maybe not even heat treated. One should make the wearing parts of a different metal or at least state of that metal.  Ian S C

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

Posted by Ian S C on 13/12/2010 00:57:44:

Jens, possibly the gears in those larger clocks are made of cast iron, maybe running on pinions made of steel, this would run better than steel on steel.  thats also the mechanical reason for using brass.

  If you disassemble an old clockwork toy, or ceap clock with pressed steel gears, you will find the pinion is badly warn with a groove the eventually won’t mesh.

  I have no clock making expiriance, but if I were to make one with steel  gears, I think I would make the larger wheel from mild/ medium carbon steel, and the pinion from silver steel, maybe not even heat treated. One should make the wearing parts of a different metal or at least state of that metal.  Ian S C

 Correct, i forgotten the cast iron in larger gear wheel … same material running togheter are a bad idea due wearing properties.

[Richard ParsonsParticipant @richardparsons61721]

 

Hello Morgens   there are two books which whilst they were written at the middle of the last centenary are still well worth looking at. The books are both by F.W. Britten. The most useful is ‘Watch and Clockmakers’ Handbook (Dictionary and Guide). This is a sort of encyclopaedia. The other is ‘Horological Hints and Helps’. I think I bought my copies (which are reprints) from Camden Miniature Steam Services (usual disclaimer). They advertise in the Model Engineer.

What you want to do by shortening your clock will mean a complete redesign of the whole clock. There are very close relationships between the length of the pendulum, the count (number of teeth) of the ‘scape wheel, the span of the escapement and the ratios in the ‘going train’ (the rest of the cogs). It is the pendulum length which is the foundation of the whole clock. To put it more simply a clock is a device which counts oscillations. Change one part and you will have to change all.

If I may give you one more Krona’s worth of advice do not work to normal engineering ‘fits’ they will be far too tights. Clocks are built with a rattling good fit. I learned this the hard way. It took me many days to figure it out. Keep everything LIGHT! (as light as you can).

NJH – thanks for the ‘plug’. I have used the method I describe in Model Engineer and with care, it works well.  I have used it to make the wheels for three clocks so far. It can be used to make straight spokes for flywheels and other similar things. I now know how to use it to make tapered spokes, but there are complications. Until I have used it and know it works I will not write it up. If anyone has problems with the method, send me a message via this site.  I must also thank the Editor of Model Engineer for the drawings (mine were dreadful).

I will not comment on steel/cast iron wheels, I have never used them.

 

Edited By Richard Parsons on 13/12/2010 06:35:36

[Mogens KildeParticipant @mogenskilde92996]

Hello to all of you.

 

Thank you for all your support.

 

I’m aware that the beat (lenght) of the pendulum will give a clock its working speed and thus the movement of the dials, so a recalculation of the gearing will be nessasary.

 

I have ordred the book suggested by Jens, thank you.

 

I’ll bear in mind to use different material in meshing wheels.

 

 

Regards

Mogens 

[Sam StonesParticipant @samstones42903]

Hi Mogens,

Although I have only built one clock (which, as you can see in my various postings and pictures, still needs more work), I can assure you it has been a very eventful and edifying experience.

Knowing what I know now, I doubt that I would have disregarded the recommendation by a clock-maker/antique dealer to convert the design to that of a pendulum time-piece. Actually, in my mind, that would have been a disaster in itself, since the clock relies upon both appearance and animation. For me to achieve this, it has meant a fair degree of study, some testing, some calculations, and some searching for alternative materials, eg. the spring. It has also involved some very generous people via this forum, and from other places.

As for choice of materials, the original design of the skeleton clock had the frames in mild steel, whereas I chose brass for reasons as suggested above, and as a better bearing material. I think it look better too. Others even use ball bearings for their pivots, which will clearly reduce the friction and wear elements.

Send me a PM if you wish to continue these ideas in greater depth.

Good luck,

Sam

[Mogens KildeParticipant @mogenskilde92996]

Hello Sam

 

Thank you for the words, I allready has found a lot of comfort in this forum, and I’m sure I’ll come back here a lot.

 

My next step in the process of building a clock will be studying as much material as I can get hold off, before I start in the workshop. This evening I’m going to the library to pick up the books recomended by Jens Skogstad

 

For now I’m unsure wether the first attemp will be of a known design, or if it will be of my own design.

Regards

Mogens 

 

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

Posted by Mogens Kilde on 16/12/2010 16:17:25:

 

My next step in the process of building a clock will be studying as much material as I can get hold off, before I start in the workshop. This evening I’m going to the library to pick up the books recomended by Jens Skogstad

 

Regards

Mogens 

 

 
Mogens..

 

In Norway we has a well explained book “Klokkemakeri” by Eigil Gjerkaas, printed 1987 (Klokkemakeri = Clock maker), The book is explaining how to make the clock, make gear cutter, table of gear dimensions, polishing of gear tooth, drawning and more… But the book are wrote in norwegian, it will be trouble for enlish man.

 

Eigil Gjerkaas was a tool maker and engineer of education, maked the klock after he ended as tool maker (pension after 67 year old)

Edited By Jens Eirik Skogstad on 16/12/2010 19:12:12

[Mogens KildeParticipant @mogenskilde92996]

Hej Jens

 

Nu kommer jeg fra Danmark, så norsk skulle ikke være noget problem

 

Sorry !

What I wrote to Jens, was that I’m from Denmark and will have no problem in reading Norwegian text.

 

 I was able to get this book from my labrary also – this forum is simply great

 

Thank you all

 

Regards

Mogens 

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

Posted by Mogens Kilde on 16/12/2010 20:23:21:

Hej Jens

 

Nu kommer jeg fra Danmark, så norsk skulle ikke være noget problem

 

Sorry !

What I wrote to Jens, was that I’m from Denmark and will have no problem in reading Norwegian text.

 

 I was able to get this book from my labrary also – this forum is simply great

 

Thank you all

 

Regards

Mogens 

 

 Hei, for deg er det ikke problem siden jeg visste at du kom fra Danmark. Men jeg tenker på engelskmenn som sikkert ville ha hatt disse bøkene som er Urmakerenes “Bibel”.

 

Translated to english with respect for englishmen:

Hey, for you it is not problem since I knew you were from Denmark. But I think of Englishmen who certainly would have had these books that are watchmakers “Bible“.

 

[Sub MandrelParticipant @submandrel]

Hi Richard,

 

I have managed to do tapered spokes, curved and ‘angled’ ones.  The patterns for the flywheel and pulleys on this model were made in aluminium on a rotary table:

 

I also made the main gear for my crane this way:

 

Neil

[Richard ParsonsParticipant @richardparsons61721]

 

Mogens   Hi there again.  I must have been half asleep or had too much palinka (a sort of Hungarian rotgut or Snaps to keep out the cold) when I wrote to you not knowing about the use of iron.  Have a look at this clock – Sorry you will have to Google for it Salisbury Cathedral clock because some of the hypertext link throws up X””$£%&***! smilies.  It has been running since 1386. The metal is certainly wrought iron (hammered not cast iron). Like the headsman’s axe at the Tower of London it has probably had a new handle and perhaps a new head but it is a real old genuine axe.

There is a modern reproduction again probably in mild steel here. The point about both of these clocks is that they are very large and are very poor timekeepers.  You should also note that they use ‘Lantern wheels’ not pinions. Unlike Harrison’s lantern wheels in his chronometers where the bars rotated in brass disks these do not rotate. From the look of the reproduction of Wallingford’s clock the gears are involutes and in the Salisbury they were ‘filed up to fit’

Edited By Richard Parsons on 17/12/2010 16:13:21

Edited By Richard Parsons on 17/12/2010 16:20:39

[Tony JeffreeParticipant @tonyjeffree56510]

Richard –

 

Nothing at all wrong with lantern pinios. The poor timekeeping is basically down to the verge and foliot escapement, not the construction of the rest of the clock.

 

Regards,

Tony

[Ian S CParticipant @iansc]

As a time keeper, the Salisbury clock was the Rolex of its day, given todays materials, and tools to work them, what would they have built 624yrs ago? There seems tobe nothing new, just the availablity of materials and methods of using them.  Ian S C

[Richard ParsonsParticipant @richardparsons61721]

 

Yes the Salisbury clock was the Rolex of its day. Of course it was used to trigger the bell or ‘Clocher’ which summoned the inmates to do their services (matins, vespers complin etc). The clock was looked after by brothers called ‘Vergers’ who used sundials to help them reset the machine. The point about the machine was that it would run and give them the time during overcast weather, at night and could ring bells.

The real quantum leap was the use of both the Verge escapement for marking the passage of time and the ’fan’ used to control striking mechanism. Richard of Wallingford’s verge is a real ‘dainty’. In many ways it was easier to build than the pallet verges with their large ‘scape wheel. 

Has anyone ever measured the accuracy with which the Salisbury Clock was built? The ‘clock wrights’ had no standards to work with. You could not go out and buy a 6 “ ruler. No machine tools (much) just forges, hammers, etc. The instruments they had were dividers, trammels, scribes and straight edges. How did they make the straight edges? 

Somewhere in Salisbury there are the Master Mason’s marks which were the reference point for the Stone masons to work from.  These determined the size of the whole building and each part of it. 

[John HaineParticipant @johnhaine32865]

Someone, I think Dick Stephen, has described making pinions from mild steel and case-hardening them

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by Ian S C on 18/12/2010 01:03:18:

As a time keeper, the Salisbury clock was the Rolex of its day, given todays materials, and tools to work them, what would they have built 624yrs ago? There seems tobe nothing new, just the availablity of materials and methods of using them.  Ian S C

 Ian –

 

It may have been the Rolex of its day, but there is plenty new since then other than new materials and methods. Clocks didn’t start to get reasonably accurate until the invention f pendulum-based escapements; that wasn’t just a case of new materials and methods of using them, it was a step change in knowledge and technology based on that knowledge.

 

The answer to your question ” given todays materials, and tools to work them, what would they have built 624yrs ago?” is “not a lot” in reality, because they didn’t have the rest of the infrastructure to support using today’s materials and tools, and more importantly, to produce more of them. And even if they overcame that problem it still would have required the leap of imagination involved in inventing a pendulum-based escapement before anything really changed.

 

Regards,

Tony

[Richard ParsonsParticipant @richardparsons61721]

 

Terry I will agree with you. The built what they could with what they had got.

The Foliot and Verge are subject to so many variables, but they do oscillate and as such they were the first dawning of marking time by counting oscillations. How the heck did they think of that one. They had plenty of examples of pendulums but it took 300 odd years before old Galileo spotted it in a church.   

 

Before that there was the clepsydra (the water clock) and the candle/incense clock. The quantum leap was to count oscillations, which is all that our ‘modern’ clocks do.

Remember the Woodward clock ME circa 2003/4 I knocked something like it which clicked a Veeder counter one notched every revolution.  It told the time in minutes. Fun but useless for catching a train.

[Jens Eirik Skogstad 1Participant @jenseirikskogstad1]

Hello, have someone forgotten the Antikythera mechanism?   It has the gear wheels, how the ancient engineer did whith the gear wheels of metal are unknown. Do you have a idea how do make gear wheels before our modern days, more than 2000 year since?

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