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Apr 14

Scenes from Southwestern England

During the second week of my three week Easter break, Debbie and I did a little touring in the southwest of England.  Not so far from where we were over the Christmas break.  The nice thing is that it is close by so we don’t have to travel for hours and there is so much to see–why go further.  So, hold on–fasten your seat belt–this is going to be a long one but I hope you enjoy it.

We stopped first in Winchester to make a clock connection but also got a look at the cathedral and the Great Hall which is all that remains of Wolvesey Castle from the early 12th century.  This place is famous because it houses a facsimile King Arthur’s round table, hung high on a wall.  It was apparently unpainted originally but spruced up for Henry VIII in 1522.  Who knows what the real story of this table is but it is at least known to have existed here since at least 1463–not a real youngster.

The round table with King Arthur on top and the names of 24 knights written around the perimeter.

The round table, about 20 feet across, with King Arthur on top and the names of 24 knights written around the perimeter.

For those intersted in geneology, this family tree was painted on the wall opposite the Round Table in the Great Hall.

For those intersted in geneology, this family tree was painted on the wall opposite the Round Table in the Great Hall.

Next on the agenda–on our way to Bath–was Highclere house–made famous as the location for Downton Abbey television series.  It is awesome–but I am glad we came when we did–the crowds of visitors tend to detract from the enjoyment (at least for me).

Highclere Castle (Downton Abbey) - an  impressive structure!

Highclere Castle (Downton Abbey) – an impressive structure!

Even more impressive when you look close.

Even more impressive when you look close.

Next stop was our B&B for a good night’s sleep.  In the morning we were off to see the Roman baths in Bath (where else)?  Bath also has some interesting architecture with long expansive rows of apartment houses (flats).

The main bath.  There are many other rooms.  This area originally had a ceiling.  Note the statues around the top.

The main bath. There are many other rooms. This area originally had a ceiling. Note the statues around the top.

Debbie stands next to a one of the statues, a "family friend", Hadrian.

Debbie stands next to a one of the statues, a “family friend”, Hadrian.

This place does have a hotel in the middle called The Royal Crescent, but is mostly personal flats.  An amazing building!

This place does have a hotel in the middle called The Royal Crescent, but is mostly personal flats. An amazing building!

Next, a short stop at an old 15th century manor home, Westwood Manor, on the way back to our B&B for the night.  There seem to be dozens of these scattered around England and we bought a membership to the National Trust that enables us to visit them for free.  This one has surprisingly great artifacts; musical instruments, clocks, paintings–and my favorites, beside the clock (there was a welsh clock here too) are the doors and hinges.

A gilded harp is a lovely addition to the room.

A gilded harp is a lovely addition to the room.  You don’t see these very often.

I could only hope to look this good if I was 600 years old.

I could only hope to look this good if I was 600 years old.

By chance, the B&B we rented was near the little town of Westbury.  It is well known for the white horse carved into a natural chalk hillside.  The current version of this has been around for at least 500 years but some think many more than that.  On top of the hill is what is known as Bratton Castle, an Iron Age fortress.  Not much left now but the large ditches presumably around the perimeter of the castle to make a good defensible space.

We were surprised to see the white horse in the distance when we stopped at a pub for dinner.

We were surprised to see the white horse in the distance when we stopped at a pub in Westbury for dinner.

The hike up to see the White Horse was fun, unfortunately kind of a hazy day so the views were not as spectacular as might have been.

The hike up to see the White Horse was fun, unfortunately kind of a hazy day so the views were not as spectacular as might have been.

After Westbury, we headed home but not before checking in first at Wells to see the Wells cathedral.  Initially, the draw for going was to see a medieval clock in the cathedral.  This is said to be the oldest original clock face of its kind in the world. The original mechanism for this clock, currently in the Science Museum, London, are thought to be the second oldest in Britain.   There is a performance by the clock every 15 minutes–jousting knights run around and knock each other down.  Aside from the clock, the cathedral itself is the most amazing I have seen, maybe even better than Notre-Dame in Paris!  It is enormous for starters but it has wonderful scissor like stone structure on the inside as well as very large stained glass windows and a very large pipe organ.  You really have to see this one to get the feel of it.

Absolutely Awesome!  I mean that literally--awesome.  It is hard to get the sense of it from a photo.

Absolutely Awesome! I mean that literally–awesome. It is hard to get the sense of it from a photo.

Some of the best stained glass I have ever seen.

Some of the best stained glass I have ever seen.

apparently these criss-crossing arches are unique and were added (in 1313) to stop the tower from falling down after cracks in the structure were discovered.

Apparently these criss-crossing arches are unique and were added (in 1313) to stop the tower from falling down after cracks in the structure were discovered.

Of course, I have to include the clock.  This one has an original dial from the late 1300s--the second oldest remaining clock in England. At the time this clock was made people still thought the sun revovled around the earth.  Above the dial, knights joust every 15 minutes.  After the clock strikes on the hours a live priest says a pray--a nice touch, I thought; changes the focus from what man has done to what God has done.

Of course, I have to include the clock. This one has an original dial from the late 1300s–the second oldest remaining clock in England. At the time this clock was made people still thought the sun revolved around the earth. The dial shows the sun revolving around the earth and indicating the hours.  Copernicus first challenged the belief in 1543.  Above the dial, knights joust every 15 minutes. After the clock strikes on the hours a live priest says a pray–a nice touch, I thought; changes the focus from what man has done to what God has done.

One more stop on the way home was to Stourhead.  This is a large estate with a long and storied history, and a perhaps typical, large estate house–huge library, lots of paintings and sculpture–a bit Downton Abbey like.  And there are also large grounds and natural gardens, that Highclere doesn’t have.  We didn’t have as much time as we might have liked but certainly enough to be awed and appreciative both of the natural beauty but also of the massive effort it must have taken for a family to build something like these places.

The main house at Stourhead.

The main house at Stourhead.

A picturesque scene created by man.

A picturesque scene created by man.

 

The rooms are full of paintings--there certainly isn't the time to study them all.  Many are of religious themes--notice the three wise men bringing gifts to the baby Jesus in the center painting.

The rooms are full of paintings–there certainly isn’t the time to study them. Many are of religious themes–notice the three wise men bringing gifts to the baby Jesus in the center painting.

Back home then and I have some serious work to do completing a 2000 word essay on the intangible and ethical aspects of my Master’s conservation project–want to trade places?

We’re off to Spain next week–cheers,

 

Apr 11

Making a Center Wheel

This is Part 3 in my story of a verge re-conversion.  In my last blog about this project, “What’s a Potence?“, I described making some of the important supporting parts for the wheels.  In this blog we are going to take a step back and describe what happened after the Precision Operation.  The center wheel needed a new pivot and it also needed a new wheel because the wheel that was in place did not have the right number of teeth for the verge configuration and it was not the original wheel–it had been replaced sometime in the past, most likely when the clack had been modified to take the new escapement.  This new wheel was made in the then new style, that is, the teeth were shorter and spaced more closely together.  Clocks in the early 1700s had different shaped teeth so this was another reason to make a new center wheel–I need to create new parts that look more consistent with a style appropriate to the era it was made.  The challenge here was that the cutters made now are of a newer shape, so how to get the shape of older teeth.

Can you see the difference in the shape ans spacing f the teeth on these two wheels.  The one on the left is the newer wheel that I am replacing, whist the one on the right is an original wheel from the striking train.  The new wheel should have teeth that look more like this.

Can you see the difference in the shape ans spacing f the teeth on these two wheels. The one on the left is the newer wheel that I am replacing, whist the one on the right is an original wheel from the striking train. The wheel I am making should have teeth that look more like this.

The right cutter is selected to give the desired shape tooth.  Then, by means of a indexing plate, the wheel is moved around in exact settings 84 times so that each tooth can be cut.

The right cutter is selected to give the desired shape tooth. Then, by means of a indexing plate, the wheel is moved around in exact settings 84 times so that each tooth can be cut.  The tooth depth is set by moving the cutter in slowly and recutting until there is no land left on the tooth top.  You can see the first few tries in the picture until the depth gets just right.

After cutting out a circle of cast brass and hammer hardening it, I faced it off to the right thickness–the next step was to cross it out and put in onto the wheel.  Crossing out is harder than it seems but it not too bad once you have developed some filing skills.  I will have to wait to show you that process.  But now, before I can put the center wheel on the arbor, I have to make a collet to mount it on.  The collet is also made of a piece of cast brass–start with a round piece and cut it to the approximate size needed.

Cast brass rod for shaping into a collet.

Cast brass rod for shaping into a collet.

The collet is roughed out and ready to solder onto the arbor.

The collet is roughed out and ready to solder onto the arbor.

The arbor looks kind of ugly after soldering on the collet--but not to worry, it will all get cleaned up.

The arbor looks kind of ugly after soldering on the collet–but not to worry, it will all get cleaned up.

Then shape the top end into a cone so that the the wheel just fits over it.  Once you have this, you can just skim off brass lightly until the wheel can be pushed completely onto the collet with a tight hand fit.  This lets me put the wheel into the clock and test it later with the next wheel in the train to make sure that they work well together.

A cone shape ready to accept the wheel.

A cone shape ready to accept the wheel.

The wheel fits perfectly onto the collet.

The wheel fits perfectly onto the collet.  Note that the wheel has been crossed out–meaning that the extra brass has been cut away out of the center to create spokes.

Stay tuned for more progress on this clock.

cheers,

 

Apr 10

Be It Ever So Humble …

Be it ever so humble, there’s no place like home.  It is good to be home after some time traveling about.

It has been a long time since I checked in with you all–my apologies.  However, we have been quite busy.  I have been working hard finishing off as much as I could before the end of our second term, which was a couple weeks ago; 27th March.  Now we are on three weeks break before the third term begins.  In some ways I really didn’t want a break because it seems like there is a lot to do at school, but I am also glad for the break because it is the last one that I will get before the end.  People on the normal courses at West Dean end in mid-July for the summer; Master’s students continue through summer without a break after the third term.  I am hoping that I will be organized enough to be able to take some small breaks in the summer anyway so that we can do some short visiting trips–we’ll see.

So since this recent term ended we have been to Vienna to see my brother Norman and his family, we have also just returned from parts in the southwest of England: Winchester, Bath, Wells, and Stourhead, plus some more.  After all the travels–and they were very nice–it is still really good to get back home.  Yes, I did say home–we have been here long enough now so that Chichester does feel like home and be it ever so humble, we do feel comfortable, relaxed and are enjoying our little flat here and our little town (though they call it a city).

In addition to visiting and sightseeing, this time off has been full other things too.  I completed our income taxes (thank goodness for internet filing), and I also have a 2000 word paper to write in the next couple days–and, believe it or not, we actually made flight reservations to return to the US, first of October.  To finish off this three week break, we are taking a trip to Malaga, Spain, to see my nephew and his family and to spend a few days reminding ourselves of what it was like to be by the Mediterranean.  Debbie and I spent two years on the island of Crete many years ago–but that is definitely another story.

To finish off this blog, I am going to leave you with some of the highlights of our trip to Vienna.  Following soon, I will share some photos of our visits in southwestern England.

cheers,

 

We're walking up to the hill behind the summer palace for some nice views.  Do we look cold?  Despite the cool weather, we did get some lovely sunshine.

We walked up to the hill behind Schonbrunn Palace for some nice views. Do we look cold? Despite the cool weather, we did get some lovely sunshine.

Lots of horses and carriages around.  They sound nice clomping in the street.    This is taken inside a courtyard next to the Imperial Palace.  Notice the Sundial right below the clock--guess they didn't trust the clock!

Lots of horses and carriages around. They sound nice clomping in the street. This is taken inside a courtyard next to the Imperial Palace. Notice the Sundial right below the clock–guess they didn’t trust the clock!

A street scene next to the  Naschmarkt.  The architecture all around the city is amazing!

A street scene across from the Naschmarkt. The architecture all around the city is amazing!  (Hey, they drive on the right side of the road here.)

Inside the Naschmarkt--a fun place with all sorts of goodies--foodies would never be able to leave!

Inside the Naschmarkt–a fun place with all sorts of goodies–foodies would never be able to leave!

We took plenty time to sample the local cuisine.

We took plenty time to sample the local cuisine.

 

Mar 18

Paris in the Spring

All the Conservation students from West Dean are now in Paris for three days to view museums and sites. Officially we are here to learn about how our craft and how different museums and dealers approach conservation. Many conservators like to keep things pretty much as they are without doing much restoration or shining things up.  Dealers in the other hand more often likely to make things shiny and replace missing parts etc.  that is what they think is necessary to sell an antique.

What about you?  Would you buy an antique clock because of its intrinsic historical value even if it didn’t work?  Or do you value it because it is 200 or 300 years old and not want to damage that well aged surface and worn finish?  Most clock owners want their clocks to work which typically means doing some restoration work on the clock–how much is too much?

This post is necessarily short and cryptic due to the fact that I have done it all on my iPhone on the bus as we are going into Paris for our second day.

image

imageimage

Some portable clocks from the 17th century.

Some portable clocks from the 17th century.

Cheers,

Mar 08

English ‘speak’!

Hi All,

Thought it was time for another blog update, but there is not a lot new to report.  We’ve done a bit of tootling round; went to London one day for Mostyn to see a voice specialist.  It’s such an easy trip on  the train.  It was quite a chilly day especially walking across London Bridge that spans the Thames River.  We hadn’t been to St. Paul’s Cathedral, so we walked over there after his appointment and caught the tale end of a Lenten service.  We likely would not have been able to get in at all if they weren’t worshiping, so we were grateful that it is still faithfully being used for services.

Dont let the picture fool you--it was literally freezing when I took this picture.  A cold brisk wind from blowing across the London Bridge we were standing on--but lovely all the same.

Dont let the picture fool you–it was literally freezing when I took this picture. A cold brisk wind was blowing across London Bridge–but lovely all the same.

The Winchester Guildhall built in 1871.  Winchester is known as the ancient capital of England.

The Winchester Guildhall built in 1871. Winchester is known as the ancient capital of England.

Last weekend we made a day trip to Winchester by car.  Rainy and gray, but lunch with new friends, a visit to a water mill that grinds wheat, and finding a high end clock shop just adjacent to the large cathedral, made for lovely day despite the weather.

We went to London yesterday for a tour of a clock exhibition at the Science Museum and to look for some other fun and interesting things to do.

The Natural History Museum

The Natural History Museum–we only had time for a quick visit but all the big museums are free.  There was a big line for the dinosaur exhibit but we skipped that.

Then in 2 weeks Mostyn is going to Paris with all the students from West Dean and I will go to Reading to visit his sister Nancy and husband Peter.  The end of the month we are headed to Vienna to visit his brother, Norm and family and in April we will be in Spain to see his nephew and family and soak up some sun. Needless to say we are not lacking in adventure!  Of course the event we are most looking forward to is the visit in May of all our kids and grand kids.  They will be here for 3 weeks and we will cherish every single second!

Several have wondered if we will adopt a British accent while here.  It is not likely, as we get so many compliments on ‘our accent’.  What you will probably hear however, is some strange new words that we have learned to use.  Here is a narrative to include some of these terms to warn you of possible changes in our speech:

When one is driving on the dual carriageway(freeway) the lorries (trucks) are often seen in the lay by’s (rest areas) or at the petrol (gas) stations, unless of course they are trying to access the high street (main road where all shops are) or a car park (parking lot) in the city.  They may even be parked partly on the pavement (side walk) to unload and still leave room for other cars to pass.

If you become ill you’ll need to ring up (phone) the surgery (Dr.) who may need to send you to Boots (drugstore) for the chemist (pharmacist) to prescribe tablets (pills) for you.  While there you may need to buy some plasters (band aids) or nappies (diapers).

While in town on the high street you can shop for trainers (tennis shoes), a new jumper (sweater), wellies (rain boots), or add a new brolly (umbrella) to your kit (all you need to complete an outfit).  You’ll need pounds or quids (money) and will probably have to stand in a queue (line).  The checker who may have a fringe (bangs in her hair), will greet you with hiya (hello) and may be gobsmacked (surprised) to hear you speak.   You may need use the lift (elevator) to the loo (restroom) which is often found upstairs.

It is summat (somewhat) of a puzzle at times finding the small take-aways (fast food) unless you the know the twittens (short-cuts) and are not too knackered (tired) to walk to the chippie (fish and chip take away) for dinner.  You could instead walk to the pub (bar) for a pint (glass of beer) or tea (light dinner) where  you may order a variety of dishes including gammon (ham) and bangers (sausages) and followed by a pudding (dessert) or a biscuit (cookie).

When your diary (calendar) is full and you have finished hoovering (vacuuming), done the washing up (washing dishes), and emptied the bin (trash), you can take a holiday (vacation) to relax and rest up.  But be sure to take your torch (flashlight) as not all holiday lets (vacation rentals) tick all the boxes (have everything you want or need).

When we return and you hear us use some of these strange words, just be patient with us, we will revert to ‘American’ eventually.  However it is very likely that we will be traveling back to Britain again.  This is not a one off (one time only) trip and we hope to return, as we rather like here!!:)

Spring is literally just around the corner and bulbs are bursting out all over the place in small clumps and large expanses in the fields.  The sheep are beginning to lamb and you can feel the warmth of the sun when it actually shines.  All of this we welcome as the long dark cold winter days are getting a bit old.

Spring has sprung here although the days are still cool.

Spring has sprung here although the days are still cool.

No mowers on these lawns for a while.  It is lovely to see the bulbs poking up their heads and reminding us that the cold winter days are almost gone.

No mowers on these lawns for a while. It is lovely to see the bulbs (snowdrops and crocus in this photo) poking up their heads and reminding us that the cold winter days are almost gone.

I believe you change to Daylight Saving Time this weekend.  We however have to wait till the end of the month.  So for a few weeks we will only be 7 hours ahead of you, then we will return to being 8 hours ahead when we change our clocks here.  Oh and Mother’s Day here is this month; some tradition from a previous era where servants were given this one Sunday off to be with their families, that has something to do with Lent??

Many differences, but many likenesses too.  We have been so welcomed here and on Sunday we got ‘fought over’ by two families at church who both wanted us to come over that day.  We ended up at both houses!

So that’s it for now.  We are well and doing great.

Debbie

Feb 21

What’s a Potence?

The back plate--some beautiful engraving!

The back plate–some beautiful engraving!

This week I made a potence–actually I made both a top and a bottom potence.  What’s a potence you say?  Well, you know that I am working on old clocks–the origin of this word goes back to the Medieval Latin word for a crutch–basically a device used for holding something up.  The top and bottom potence I made are used in my clock to hold the crown wheel in a vertical position.

I am continuing to work on the same clock that I told you about in A Precision Operation. In that post I mentioned that I was doing a verge reconversion, well, this post is a continuation of that work.  If you follow my posts over the weeks, you are going to see this reconversion come together.  A verge escapement consists of pallets and a crown wheel.  These can be placed in a vertical or horizontal orientation but in my clock the crown wheel is vertical–actually the crown wheel itself is horizontal but the arbor (axle) that it is mounted on is vertical.  The bottom of the wheel arbor is held up by the bottom potence and the top is kept in a precise position by the top potence.

To make these I started with a large piece of cast brass.  I cut off a small piece of this that was the size I needed and then kept cutting.

This is the piece of solid cast brass I used for the bottom potence.  Making nice straight cuts with a hack saw is a patience building exercise--more like a marathon than a sprint.

This is the piece of solid cast brass I used for the bottom potence. Making nice straight cuts with a hack saw is a patience building exercise–more like a marathon than a sprint.

The very rough bottom potence.

The very rough bottom potence.

 

 

 

 

 

 

 

 

 

 

Before you start cutting however, you have to make some precise drawings of the exact shape that you need.  I started by laying the back of the clock (back plate) on a piece of paper and tracing it.  Would you believe there are almost 50 holes in that back plate?

When you have some pieces that are roughly the shape and size you need, you then need to  mount them onto the back plate in exactly the correct place.

But before you can do that, you need to have some screws to mount them with.
So, you guessed it–I had to make the screws.  Now, not all screws are equal, and in the 18th century, they didn’t have the nice machinery that we have today–they made their screws with screw plates. This resulted in the shape of the threads being further apart and more rounded and since I am trying to be somewhat authentic to the period, I used an old screw plate to make the threads.

I started the screws with a piece of steel rod and cut away to the thread diameter, then, after tapering the shank a bit, I slowly rotated the screw plate onto the shank making the threads.

The tapered shank before threading.

The tapered shank before threading.

Threading the screw.

Threading the screw by slowly turning the shank into the plate.

 

 

 

 

 

 

 

 

 

 

Then it is pretty simple job to cut the screw to length and finish off the head.  Of course, all things were different then and even the slot in the top of the screw head is a tapered slot meaning the slot is v-shaped rather than having sides that are parallel.

Finished screw.

Finished screw.

 

 

 

 

 

I had the two potences and the screws–now to get them in the right position.  This takes some careful work and understanding what all the connecting parts look like.

In this picture I have put the actual clock on top of the drawing I made to design the new parts with.  You can also see the tape I used to position the bottom potence with.

In this picture I have put the actual clock on top of the drawing I made to design the new parts with. You can also see the tape I used to position the bottom potence with.

Lining up the top potence--it has to be right in the center.

Lining up the top potence–it has to be right in the center.

I used a piece of tape to draw the correct positions on the actual clock.  Then I could mark the place for the screw hole accurately.

I used a piece of tape to draw the correct positions on the actual clock. Then I could mark the place for the screw hole accurately.

Ready to put the pieces on to the clock now except there are no threaded holes to accept the screws.  Perhaps you are beginning to understand why it takes a whole week to do this–at least when it is the first time you have ever done it.  So another timeout while I go off and make a tap.  I made the tap in the same way that I made the screws except the tap is left quite hard so that it will stay sharp as it cuts.  Tempering steel is topic that I might cover in another post but suffice to say that you can make steel very, very hard or not very hard and lots of places in between.  If it is too hard it will beak very easily, so you want screws to be not hard or they will snap off when you tighten them.  A tap on the other hand may snap (and many do–I have snapped a few myself) but they can’t be too soft or they will dull very quickly as you try to cut with them.

I made this tap using a screw plate as a pattern.  It is fun to make almost every part of a clock including the tools needed.

I made this tap using a screw plate as a pattern. It is fun to make almost every part of a clock including the tools needed.

Using my tap to put threads into the top potence.

Using my tap to put threads into the top potence.

 

 

 

 

 

Now we can put these pieces in place.

The top and bottom potence in place.

The top and bottom potence in place.

That piece of black wire is pretending to be the arbor of the crown wheel.  It sits on top of the bottom potence and is held in position by the top potence.

That piece of black wire is pretending to be the arbor of the crown wheel. It sits on top of the bottom potence and is held in position by the top potence.

In addition to all of the above work, we started off with the official Masters programme this week–afternoon classes that run until 7:00 PM.  In addition to a thesis we have a whole boat load of work that is required, including two essay questions (not short ones either) and an oral presentation.  Well, no one said it was going to be easy–I now believe they are really after training you to be a conservator.

Stay tuned to see this verge reconversion come together.

cheers,

 

Feb 15

The Main Thing is the Mainspring

The reason I came to West Dean College was to get a Masters Degree in Clock Restoration.  Of course, in addition to learning about making and restoring clocks I have to do some research and write a paper for the Masters Degree.  Through the year so far, I have been preparing to do the research and write the paper.  Of course the first thing is to decide what to write the paper about.  I didn’t come to college knowing what I would research but workshop conversations led me to wonder why clock mainsprings get replaced so often.  Indeed for some repairers it is routine whether apparently needed or not.  From a conservation point of view, this may not be the best practice since throwing away a mainspring is throwing away part of the history of the clock.  For many clocks, the history of the mainspring may not be that important, so, no big deal–.  But what about the other ones? and how do you know how old the mainspring is?  Something that we are being taught to appreciate and look for are the evidences that would help us to verify that it really is an old clock–evidences that would perhaps help the ability to date the clock.  A mainspring is perhaps a part of the clock that could help with that, if only you had some way to tell how old the mainspring was.  My research is leading to find ways of telling how old a mainspring is.

One part of that research will be understanding the torque that the spring has.  This blog post reports on a test set-up that I am using for my MA project paper.  So, here’s your chance to opt out of reading this blog–might be too boring.

I have devised a testing jig to measure the torque of mainsprings.  It is flexible to be used on multiple mainsprings since I plan to measure around a dozen different mainsprings.

Clock mainsprings are mounted on a winding arbor and enclosed in a barrel.

Two mainspring barrels shown on right--square winding arbors are in center of the barrels.

Two mainspring barrels shown on right–square winding arbors are in center of the barrels.

This is the main part of test winding mechanism.  The center square is replaceable to fit different size winding squares.

This is the main part of test winding mechanism. The center square is replaceable to fit different size winding squares.

The winding arbor has a square end normally used for winding the clock with a key.  This provides a convenient place to attach a winding mechanism for my testing.  The objective of my test is to measure the torque and linearity of a mainspring at different degrees of winding tightness.  If I remove the mainspring barrel from a clock and clamp it securely, I can attach a measuring tool onto the winding arbor—wind the spring to varying degrees and measure its torque.  The results can then be plotted and analyzed to discover the differences between the springs that I intend to research for my Masters project.

Test Setup

Test jig drawing for the workshop.

Test jig drawing for the workshop.

I devised a brass disc with a removable center.  The center contains a square hole to fit the winding square on the arbor.  This center piece can be easily replaced with another of the correct size for different winding arbors.  The small square piece is held inside the large disc by a threaded screw.

The large brass disc is also fitted with a long threaded rod about 40 cm in length.  This rod need only be thick enough to remain straight when a weight is put on its end.

I gave a test jig drawing to the workshop for them to make of wood and I made the brass and steel parts from scrap pieces in the clock workshop.

The jig also contains some safety features—springs can store a lot of power that, if unlocked inadvertently can be very dangerous—a stop mechanism so that the spring will not be able to unwind all at once and also so that if I need to do anything when the spring is wound, it will stay wound.  A second safety feature—not as important—was a knob that I screwed in to the end of the threaded rod.  This makes it much easier to wind up and down without potential scratches or cuts to the hands.

Analysis Preparations

The measured masses and calculated torque for test items.

The measured masses and calculated torque for test items.

Before I started trying things out, I wanted to understand what measurements I needed to make and what calculations I would perform with the data.

The equation for torque (T ) is:  Torque = force x distance = (mass x acceleration) x distance

We can calculate the torque for my test configuration by knowing the mass added to the threaded rod and the distance it is placed from the center of rotation.  In this case, acceleration is that due to the force of gravity, 9.81 m/s2.

Another thing I needed to do before any calculations could be made is account for the forces due to extra mass of parts other than the mass that I placed on the rod, i.e., the mass of the threaded rod, the nut, the hanging wire and the knob.  I measured the mass of each part and for those that have a fixed position, I can calculate the torque and add it to the calculated torque at each measured position.

Testing

Now, I set the jig up on my bench in the Clocks Workshop and gave it a try.  I first wound the spring completely to see how many turns it would make and then I placed a weight attached to the threaded rod with a piece of wire until the rod balanced in a horizontal position.

The test jig with the measuring rod balanced by a large mass.

The test jig with the measuring rod balanced by a large mass.

A horizontal position for the balanced bar may seem obvious but it really is not.  It is not absolutely necessary but it does make the calculations easier because the force vectors from gravity (on the weight) and from the spring torque are exactly 180° from each other.  If this were not the case, I would need to use a vector diagram and trigonometry to help me determine the forces at work.

A close-up of test jig shows the safety bar and Plastazote around mainspring barrel to protect it from damage in the clamp.

A close-up of test jig shows the safety bar and Plastazote around mainspring barrel to protect it from damage in the clamp.

Finally ready to make some trial measurements, I wound the mainspring as much as it would wind.  Since the rod ended up in the lower vertical position after I fully wound the spring, I unwound the spring and moved the winding square 90° counter-clockwise so that a full wind position would be in the right-side horizontal position and I could get a measurement at full wind.  I placed the large mass on the rod until it balanced as in Figure 5.  I then measured the distance between the center of rotation and the hanging wire for the mass.  After writing the distance down, I rotated the rod counter-clockwise one rotation and made another measurement.  This I repeated until the mainspring was fully unwound—it was nine turns.  On the lower two turns, the mass was quite close to the center of rotation so I changed mass to a lighter mass.  I realized afterward that using the smallest mass possible at the farthest position possible is the most accurate because at farther distances a change in position (one thread on the rod I am using) is a smaller percentage of the total distance than if the mass was close to the center of rotation, enabling smaller percentage modifications (more accurate) to the balancing position.

Analysis

I tabulated the data from two runs on Excel and plotted them.

Torque ChartThis chart is almost what I expect to see except that it is more linear than I thought it would be.  The interpreted linear line shown on the graph shows how the actual torque deviates from perfectly linear.  As I test other springs, this will be one point of comparison.  The chart shows a high degree of non-linearity as the spring first begins to unwind.  As I wound the mainspring I was able to feel that there was friction in the mainspring and barrel as I rotated it with a high number of turns. Also shown on the chart is the equation of the calculated linear regression line and the R-squared value which is a measure of how well the actual data points fit to the straight line.  This will be one good way to measure the differences between springs.

The linear regression method of predicting the best linear fit to a group of data points is a method that minimizes the squares of the deviation of all the data points from the proposed line.  The R-squared value is the correlation coefficient, i.e., an indicator of how closely the best fit line matches the data points.  A perfect correlation would result in a coefficient of value 1, so the R-squared value shown on the chart, 0.9274, shows not great correlation.  Probably, I will be eliminating the end points of the curve prior to doing this correlation test–but we’ll see as things progress.

Even though the torque may be very linear (in the middle portion), the chart also indicates the slope of the curve.  That means that the torque is not the same as it unwinds.  This leads to uneven operation of the clock.  To counteract this effect, many mainspring driven clocks in the 15th to 18th century used what is called a fusee.  You can see this in the first photo; it is the cone shaped item just to the left of the mainspring barrels.  This device was intended to smooth out the torque curve and make it not just linear but constant throughout the unwinding process.  That way a clock is more likely to run at an even pace throughout a single wind.  I will need to devise an addition to this test jig to be able to test the mainspring and the fusee at the same time to see how well it does the job.  The excel spreadsheet and linear regression analysis will enable me to quantify the results.

One aspect of my research will be to understand the impacts of friction in the spring barrel.  It is interesting to see that this has already become apparent on the first set of measurements (I suspect that the reduced slope between turns 1 and 4 is due to this friction in the barrel).  I plan to clean the spring and to remove sources of friction inside the barrel if possible to see how that changes the torque curve.  This is an important conservation issue related to how cleaning can affect the operation of the clock not just its degradation processes or it’s “good looks.”

I will let you know how the testing is going with another report soon.

Thank you to those who stuck out reading through this blog – I hope you learned something – as a reward, here’s a photo of the school workshop just before I take off for home in the evening.

My workbench is just inside the left window of all the windows that are in a row on the second floor.

My workbench is just inside the left window of all the windows that are in a row on the second floor.

cheers,

Feb 07

Holiday Break; Phase 2

We woke up to snow this week outside our house.

We woke up to snow this week outside our house.

It has been quite a time since I posted something on the blog – I apologize, but things have gotten quite busy at school.  Next week is our mid-term assessments, meaning we get a mid-term grade.  We had writing assignments  for science class and I have been trying get make some progress on my Masters paper.  There are outside people that come in and check on us as well as our own instructors (called tutors here).  I am doing fine–probably around a B+.  Certainly one of the biggest challenges here is managing the priorities of all the different things that are required to do.

The bike trail on the way to school was white.

The bike trail on the way to school was white.

We had some snow this week for the first time–not enough to stick for any length of time but it was fun to see it come down.  Apart from the snow the weather has been quite cold–below 40 degrees.

I had the below written for some time–it is going back to our Christmas break- have fun.

Continuing with a few more bits about our trip to the southwest of England.  After Swanage we moved further west along the South coast.  We headed first a bit North to Hinton Martell to see a clock buddy, Chris McKay.  Chris was a speaker at the Time Symposium in Pasadena last November.  He is also the best known, perhaps the most knowledgeable turret clock guy in the world. He has recently published a book about Big Ben that is the most complete book on that topic ever written.  He is also Chairman of the Dorset Clock Society; a group to which he has invited me to speak in March.  I will be talking about the tower clock work at the Santa Barbara county courthouse (of course).

We then moved on west to Dartmouth but not without a little mishap on the way.  Somewhere between there and here the car engine just stopped.  We unfortunately did not have enough space on the side of the road to roll off so we got out and pushed to a larger space off the other side of the road.  It would not start and there was a significant smell of fuel.  I looked at the engine and was fortunate enough to notice around the carburetor that the fuel hose had fallen off.  I popped it back on and we were off again – whew!

Dartmouth is a big sailing center--in fact you can see the Royal Naval College in the background of this photo.

Dartmouth is a big sailing center–in fact you can see the Royal Naval College in the background of this photo.

The passenger ferry between Dartmouth and Portswear.

The passenger ferry between Dartmouth and Portswear.

We finally arrived in Dartmouth to rain and a pretty stiff wind.  It was hard to find our B&B in the dark and there was not much space to park on the steep hill, so getting out to look around was more than trivial.  We finally found it–it was lovely and a very inviting place to come out of the rain.  After settling in for a bit, we did venture out to find a bite to eat.  Our B&B was actually on the East side of the river Dart, called Portswear.  Dartmouth itself is on the West side of the river and has all the shops, restaurants, etc.  To get across the river there are two ferries, one is just for pedestrians and the other carries both cars and pedestrians.  The ferries are a quite nice part of the feature of the town and very convenient for a a short five minute crossing.

the car ferry is a kick!  A small tug ties itself to barge and that's it.

The car ferry is a kick! A small tug ties itself to the barge and that’s it.  I think we were the only car on this trip.

Next morning we woke up to beautiful views of the river and Dartmouth on the other side – albeit cloudy and quite a good wind.

Wake-up Sunrise!

Wake-up Sunrise!

The weather has not held us back though – many of the more famous places, like Greenway, the home of Agatha Christie, are closed for the holidays – so we went to visit Colton Fishacre.  This is the country home of a the D’Oyly Carte family built in the 1920s.  Rupert inherited an opera company as well as the Savoy Hotel and Theatre company from his mother-in-law.  They created an amazing garden that has many plants brought from various parts of the world – looks like it could have been a garden in Santa Barbara.  Also a very nice house that has been preserved as it was in it’s heyday and now kept by the National Trust.

Dartmouth castle from our B&B.

Dartmouth castle from our B&B.

Then we visited the Dartmouth Castle – a small fortress built in 1388 originally to protect the town.  It is accompanied by Kingswear Castle on the other side of the river mouth.  At the time of building, the range of a cannon was too short to protect the whole channel.

Dartmouth is an interesting town with a lot of history – interesting connections to WWII and lots of seaside and sailing focus.  We would both recommend this as a holiday destination.

Tomorrow we are off again for points further west in Cornwall.

Sorry this post is out of order but there it is – hopefully it won’t take so long for me to get to the next one.

best,

Feb 07

A Precision Operation

A nice bracket clock from the early 1700s.  These old clocks have been worked on many times.

A nice bracket clock from the early 1700s. These old clocks have been worked on many times.

One of my practical work assignments of late is to do what we call a verge re-conversion on a nice old bracket
clock from about the mid 1700s, made by James Snelling.  These old clocks, before the anchor-recoil escapement was invented, used what we call a verge escapement.  Later, after the pendulum was invented, many clock owners wanted their clocks converted to use a pendulum as a regulator because they keep better time (a point under some debate in horological circles).  In any case, nowadays, many current clock owners are wanting their clocks of this era converted back to “the way it was”.  Much debate about this process also–do we really know “how it was”?  In many ways we are really just adding to the history  of the clock not taking it back to something.  In any case, as an educational experience it is very instructive so this re-conversion is what I am doing.  The re-conversion process involves making new wheels (gears) and their associated mounting pieces–in my case this will also involve making a pendulum and crutch which uses a rise and fall mechanism to adjust the rate–so a little bit more complicated than might be typical.

As is usual with most clocks, you can’t ever get around to doing what you want without first having to fix a few other problems.  As I was taking apart my clock to get to see what things looked like inside, the center wheel came off leaving the pivot in place in the back plate.

Here is the inside of the clock-the center arbor is the one in the middle that looks like it is tipping over.

Here is the inside of the clock-the center arbor is the one in the middle that looks like it is tipping over.

OK, a pivot is the little end part of the clock wheel’s axle (called an arbor)–the pivot is the part that holds the wheel in place as it rotates.  Hopefully the pictures help you with seeing this.  Before I can begin work on the re-conversion, I need to put a new pivot into this arbor.  If things are bad enough you have remake the whole gear.  In my case, I am going to try to reinsert a new pivot into the arbor end – if that does not work, I will have to make an entirely new gear assembly.

The pinion (star gear) with the pivot missing.

The pinion (star gear) with the pivot missing.

The pivot is stuck in the front plate!

The pivot is stuck in the front plate!

In looking at the clock I noticed that the old pivot was still there–it was actually stuck in the plate, held there by old mucky oil that had gotten dirty and sticky–apparently the last person that worked on this clock tried to do the very same job of replacing the pivot but didn’t do it well enough and it literally fell out!

 

The brass bushing helps make sure that the pinion will not split as I work on inserting the pivot.

The brass bushing helps make sure that the pinion will not split as I work on inserting the pivot.

The first thing to do is get it clean–white spirits with a lot of careful brushing.  Then make a brass bushing to go around the pinion (the part that looks a little like a star wheel).  The pinion is vulnerable to splitting as I am poking a new pivot in and out of the arbor–so this just makes sure that the arbor does not split and make things more difficult.

The right end of this wire fits nicely into the arbor.  Here I am just about to cut off the small bit that I am going to use.

The right end of this wire fits nicely into the arbor. Here I am just about to cut off the small bit that I am going to use.

The pivot has been soldered in to the end of the arbor and I have turned it to be concentric.

The pivot has been soldered in to the end of the arbor and I have turned it to be concentric.

The next thing to do is to turn down the end of a piece of blued pivot wire until it fits nicely in the hole without having to be jammed in too hard.  Then, soft solder that piece of wire into the end of the arbor being careful not to heat the pinion too much–the pinion is made from somewhat hard metal and heating it too much will ruin the hardness and make it susceptible to premature wear.

Finally, I had to get the wire nice and round and importantly, concentric with the wheel.  I do this on the lathe but it is challenging because of the small size (the pivot is about 5 mm long and 1 mm in diameter) and because the pivot wire is hard steel–it takes a very sharp graver and some careful turning to get this concentric.

Once concentric you are almost home except for getting as good a polish on the pivot as possible.  The pivot is the part that turns in the clock plate so it should be as polished, low friction, as possible.  I made a couple polishing tools to help with this, the first was a piece of steel that I flattened and the second a piece of boxwood.  After making the tools, put some medium diamond paste on the steel tool and hold it on the pivot whilst turning in the lathe and then follow-up the same thing with fine diamond paste using the boxwood stick.

The polished pivot ready to be used.

The polished pivot ready to be used.

DONE! – now we are ready to move on.  Oh well almost, – I forgot to say that in order to do the pivot, I had to remove the wheel, which I was going to replace anyway, so I made a new wheel too–but that’s another process, I will share in a subsequent post.

cheers,

Jan 31

So where did January go?

Hello from snow blanketed Chichester!
2015-01-31 07.57.17

We had hoped to see snow while here and we got what we wanted.  It was a very light dusting and occurred over night, but it was nonetheless very exciting to wake up to the beautiful white blanket outside this morning.  It is Saturday, so Mostyn did not have to ride his bike to school today, though he fancies trying it at least once.  We are both amazed at how much we have acclimated to the chillier temps here, and often remark that it doesn’t feel that cold out, though it is literally freezing, at or below 0.

Mostyn in his cold weather riding gear.

Mostyn in his cold weather riding gear.

Mostyn is knee deep in his school work.  Next week he receives his first official grade and is spending every night and weekend compiling his work for evaluation.  Thus you have to hear from me again this month, as he is far too busy to write for the blog.  Maybe next month he will be able to describe all the projects he his busy with and interesting things he is fabricating from scratch and what they do.  It is all far too complicated and precise for me to even begin to explain!  So keep checking back and one day he will surprise you with photos and details of his work.  I will say, his enthusiasm for clocks, conservation and restoration has not waned and he comes home every day expressing how much he loves what he is doing.  I have no doubt he will receive a good report and will continue to be as diligent as he has already been.  We did have his tutor for dinner last week and had a good discussion about how to make West Dean more accessible for out of country married students.  Not many people will go to the lengths and expense we did to get here, so the process needs to be simplified and made more inviting, he agreed.  There are solutions, but it is complicated with aspects that involve the British Home Office and academic standards, making it slow going for quick change.  It is a very worthwhile endeavor to be here and not just for Mostyn’s acquisition of a  Master’s degree, but for the experience that we both have of immersing ourselves in the life of this lovely English town.

Chichester is small enough that I recognize folks on the street and they recognize me. More than once I have heard my name called out when in town and am stopped by a friend I have made at a Women’s group or church, or Knit and Natter (a weekly gathering at the city library).  Becoming known is such a welcome feeling and allows one to feel very much at home, though not at home!  I am having trouble now distinguishing between where home really is, as life here has settled into very much a routine that is familiar and satisfying.  I am no longer anxious using the car, though it is often not necessary as most things are available just around the corner from us.  I have needed to pick Mostyn from school on several occasions at night, which is a little more difficult, but I have mastered it and feel confident enough to not hesitate if that becomes necessary.

Early frost on West Dean village.

Early frost on West Dean village.

We are quite out of touch with a lot of news from the States, though we watch BBC World News most nights, there is not always coverage of American news.  For example to my shame being a NW born gal, we did not know the Seahawks were in the Superbowl.  Please forgive us NW family, but we are living in a far different paradigm and only hear about English football on the tellie, commonly known as soccer at home!  I did catch a Budweiser ad on Facebook, always my favorite part of the Superbowl!  Go Seahawks!!:)

We have made travel plans to Vienna in April to visit with Mostyn’s brother and family.  We are looking forward to that as Vienna will be a new explore for us and we have not seen Norm and Donna for a long time.  Also in April we have made travel plans to Spain, we plan to spend some time on the beach and a visit with the Pringle family, our nephew and niece and family living in Malaga.  So though we have acclimated to the cold we do look forward to the warmth of the Mediterranean, reminiscent of our first two married years in Crete.

The half-way point on the bike ride to school.

The half-way point on the bike ride to school.

So where did January go?  Hard to say, but it sure went fast and we have already begun to discuss what’s next, when will we be traveling back, what car to buy, how to keep things simple, and what Mexican food will we eat first as soon as we arrive!

Sadly the snow has melted and the sun is out now, so I will close with a fond goodbye to you all,

Debbie, for us both –

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