No updates for a few days.

Going to be a bit before I can work on the clock again.  I'm spending the next few days finishing up a woodworking project.  For those in the SCA, I am working on a new set of thrones for Trimaris.

Some research notes on gear cutting

  With trying to keep this project as authentic as possible, one of my great concerns has been the cutting of the gear teeth.  No documentation that I am aware of exists for how medieval clock makers would have cut the gear teeth.  I have gone back and forth on this but I believe I have a completely feasible production method.  First, the list of the different techniques.

  1)  Filing
  2)  Chisel cut then filed for cleanup.
  3)  Punch then filed for cleanup.
  4)  Sides of teeth cut with hacksaw then hot chisel on bottom of tooth gap to remove material.  Filing for cleanup.

  I think the fourth option is the most likely scenario.

  The first scenario, all filing, works for small gears made out of material like brass.  However, with the large sizes of the wheels and the fact that the material is iron it would involve a lot of filing.  Also, this would wear through many files.  I think this technique would just be too labor intensive and expensive on the files.

  Chisel cutting was a method I have thought about frequently but it has problems.  For those not as experienced in blacksmithing, the metal is heated and a chisel is hammered into the material while it is still hot.  This is usually in the 1400-2000 degree range.  This is a very common blacksmithing technique.  It has some problems as far as the teeth of the gear are concerned.  The biggest problem is that metal is always displaced as part of the chiseling process.  In other words, as I cut one tooth, the adjacent tooth would be pushed some.  I could clean this up with some careful forging.  Another problem is that much hot cutting makes it very easy to accidentally soften the chisel due to the heat.  This would probably require several touch ups and rehardening of the chisels during the work.

  I have briefly thought about punching the teeth.  This would involve creating a punch that matches the exact shape of the gap between the teeth.  While the gear is hot, the punch could be used to knock the gap out.  Problem is that punches also displace some material and they are very easy to not place exactly where you want the punch, especially when talking about a difference of 1/32" of an inch being important.

  So I am now looking at hacksaws.  When I first started this project, I believed hacksawing the sides of the teeth were the way to go.  And when I received a copy of a research article on medieval clocks from the British Museum it also indicated a belief in using hacksaws to cut teeth.  However, when I contacted the gentleman who wrote the article, he indicated that he was no longer sure about using hacksaws.

  Well, it is possible to find hacksaws in period.  Indeed, a search I did over the weekend uncovered several more examples that I was not aware that they existed.  There is one issue to be aware of with this.  Hacksaws can be used for many things.  Examples include cutting for decorative pieces such as horn or bone or cutting softer metals for jewelry.  Hacksaws really are not good for wood because of their tooth size and spacing.

  My research a few years back led me to the Viking tool chest, the Mastermyr Chest.  I made a reproduction of this about 2 years ago with a working lock and key.  In this chest was a hacksaw.  This hacksaw, from what I can see, almost exactly matches a modern equivalent.  The tooth count, tooth pitch and blade thickness all compare to a hacksaw blade that you can buy at a local hardware store.  Also, there are other metal items in the chest that have cuts that match the thickness of the blade.

  Getting the shape of the hacksaw was easy.  The difficult part may have been getting it hard enough.  When cutting iron or mild steel, you need a fairly tough blade.  I think that this was well within the capabilities of the smiths of the later middle ages.  A thin saw blade could easily be case hardened.  If the item was surrounded with carbon material such as bone or fat then wrapped in clay, it could be baked in a fire and case hardened.  I believe that this would give a hacksaw enough carbon to harden it sufficiently to cut the relatively soft wrought iron.  Also, files date back to the Romans and would have needed just as much toughness.

  I also believe that locksmiths probably used hacksaws.  Why so few examples of hacksaws then?  Very simple, they are thin quality steel and blacksmiths are the ultimate recyclers.  Once a hacksaw went dull there was a very good chance that the smith just reused the thin blade as a small spring.  And if the blacksmith did not reuse the blade and just discarded it, the thin material would have easily corroded away.  Most examples of hacksaws from the middle ages come from bogs where the material was preserved.

  So, within the next few weeks I hope to try actually cutting the gears.  I am going to cut the sides of the teeth using a hacksaw.  When I do this, I am going to use a template to make sure all the teeth are at the same angle.  Then the excess material between the teeth will be popped out by heating the gear and using a flat sided chisel to cut the bottom of the gap.  The only metal displaced should be the waste material.

Gear Work

  Well, I could not stand it any longer and I had to start the gears today.  Before I describe the process, some basic information about the gear that I am working on.  This gear is called the great wheel on the going train.  What's so great about it?  It really just means it's the largest gear on that side of the clock.  It has a 12" diameter with 96 teeth.  That comes out to about 3 teeth per inch.

  To start off, I need someway to forge the circle as perfectly as possible.  This is where the layout table comes into play.  This is what the table looks like.  You will notice too circles.  One circle has an outer diameter of 12" and an inner diameter of 9 1/2".  Also in the picture is a piece of 1 1/4" x 3/8" stock that is 34" long.  If you do your basic math you may think that that is not enough (12" x pi = 37.7").  However, the forging process stretches the metal on the outside and compresses it on the inside of the circle.  This means you actual want to use the midpoints between the outside and inside diameter when determining how much metal you need.

p.s. (Thank you Francis Whitaker for sharing this tidbit of knowledge.)

  Anyway, here is the layout table.  You can just make out the circles.  (Click on any of the images to see larger).



So, to make the circle, a portion of the bar is heated and bent using a twisting fork.



  After each heating, the bar is compared to the layout table to make sure it is staying true.  Here are some progression pictures.  I used a technique described by Francis Whitaker in which 1/4 of the circle is made on one end then you switch and work on the other end.  Not quite sure why this is but I think its to help with the tendency of the metal to twist in your hand if there is too much metal out to one side.  Anyway, here are the series of pictures.



 


Oops!  When I closed the circle, I had too much material.  The overlap is about 1 3/4" too much.



I reopened the circle a bit, cut off some material.  The circle was closed back up and welded.  The bulge of the weld can still be seen as this is prior to cleanup.  What is nice is that all around the circle it is only off by at most 1/32" of an inch.  Woo hoo!



  The only minor issue is that during the welding, I accidentally burned a small amount of steel from the edge.  It is a small amount and I think I may try to cut the gear so that a gap between teeth will be where the small amount of metal was lost.

  I next decided to start on the spokes.  This involves taking a rectangular piece of metal, splitting it down the middle on both ends.  These are opened up and draw out.  These work photos give the idea.  (Notice the punched holes, these help with the split being nice and clean.)









  I ran out of time and daylight so I had to stop before I was really done with the spokes.  However, I laid the rough version of the spokes onto the gear just to give an idea.



  So, making some real progress and I hope to start on the arbor soon.  Once the arbor is done, then I can cut the teeth.

Minor update

  I am doing some prep stuff for the gears.  Yesterday I purchased a high quality divider.  This will be used to mark the teeth for the gears.  When dividing the gears up, I will not be dividing by the number of teeth but a larger number.  For example, the main wheel on the going train will have 96 teeth.  I will first divide the wheel into 4 parts of 24 teeth.  Next, those 24 teeth might be broken up into 6 parts.  Then finally into the final four teeth.  This is just easier to lay out then trying to find the exact measurement for the divider that will handle 96 teeth.

  Next I finished cutting off a big hunk of S7 steel.  This will be used to make a top swage to form 1/2" diameter round.  The 1/2" will be the size of the arbor where it goes into the frame.  Most of the arbor will be 1" round stock.  This part of the arbor will hold the winding barrel.  The barrel is nothing more than a round cylinder of wood with a 1" hole in the center.  Other parts of the arbor will be square and this is where the gears will go.  And finally, as mentioned above, the ends of the arbor will be 1/2" round.  That is what I need the swage for.

  Finally, I made my gear layout table.  To call it a table is a bit misleading.  It is nothing more than a thin sheet of 24" x 24" steel glued to a a sheet of 24" x 24" plywood.  In the center is a small pin.  I use the pin to draw two concentric circles.  One circle is the inner diameter of the gear while the other circle is the outer diameter.  As I bend the gear, I will use these circles to ensure my gear is staying true.

  I had hoped to get more done today but it was rainy so I was not able to start until late afternoon.

More parts done...

  Got to the forge again and continued the work on the vertical posts.  These are the ones that are held to the frame using pins.  Also, almost all other clock parts will be attached to these pieces including the arbors (axles) for the clock.

  I also had to make a special shaped punch.  Essentially it is a rectangular punch with rounded ends.  I used it to help make some of holes in the new pieces.

  Anyway, here are some new pictures.  I would have taken some pictures while I was working but I didn't have the camera until the end of day.  In these new pictures you can see the 4 new parts as vertical posts in the middle of the ends and sides of the clock.

In the next photo you can see a pin holding the post on.  I only had time to make 1 pin.  I need to make 7 more for the others posts.  Also, the lettering on the post is "GT" with an up arrow.  That stands for going train which is the time keeping side of the clock.  The arrow and GT let me know where this particular bar is on the clock and its orientation.  The lettering will be removed during final cleaning.

 

Quick update...

  I did not have access to my camera today so just a description of what I worked on.

  I worked on the end uprights for the frame.  These hold the other ends of the arbors (axles) of the clock.)  In a previous entry, I had put in the vertical uprights in the center of the clock.  These uprights go on the end of the clock and are held in by pins.  In order to make these, I need to fix some tools and make a few new ones.  Here is a quick rundown...

  * Made a new rectangular drift to match the size of the pins on the frame.  This will be used to make the holes in the new pieces.

  * Fixed a few chisels.  They had been resharpened enough that the bevel of the chisels was getting too severe.  I reforged their cutting edges and rehardened them.

  * Made a new bolster plate to match the drift made up above.  If you ever do drift work with metal, it is important to have a matching bolster plate if you are concerned about the finish of the metal.

  After doing the bit of tool maintenance, I made one of the end posts.  This was really a fairly acedemic process of punch and drift.  I also made the pins to hold the post in place.  I didn't get to the post for the other end as I had some other stuff to take care of.

Pictures to follow.

Clock is a bit heavier now...

  Today I worked on the center posts.  These will hold the arbors of the clock and they are removed to allow me to create the arbor holes at a later date.  They are held in by gravity and small wedges at the top.  This shows the frame as it is now.  Remember that the center posts are removable.  And actually, any part after this point is removable from the frame.



This shows the detail on the wedges that hold the center posts in place.  The silvery powder is filing shavings from fitting the parts.

Frame is done.

  I finished up the frame today.  It took me probably about 2 hours to polish up the frame with the wire wheels.  A few spots had some heavy scale.  It seemed the heaviest scale was portions of metal where I did no hammer work.  Probably if I had done just a small amount of hammer work, it would have knocked some of it loose.  Still, managed to get most of it off.

  After cleaning up the frame some more with the scotch pads, I then applied the oil.  I think I really like this mixture.  I used a mixture of about 45% thinner, 45% linseed oil and 10% wax.  I heated the mixture to just about the point it would start smoking.  I then rubbed this mixture on the frame.  What I found interesting about this mixture is that it went on as a fluid. However, as it cooled it had more of a car wax consistency.  It seemed to spread very nicely.  After it dried, it didn't have the tacky feel that I usually get with some wax.  I'm interested to see if it darkens up as it dries some more.

  I've mentioned it once or twice but here is a more detailed explanation of what I am going to work on next.  I want to start by making the great wheel (the largest gear) on the going train (time keeping side) of the clock.  In order to work on this, I need to make the arbor (axle) and two vertical uprights that will hold the arbor.  For all of this, I need to make some tools before I can make too much progress.

  1) Long rectangular punch.  This will be used on one of the vertical uprights to allow it to fit the end tabs on the frame.  I will also make a matching bolster plate.

  2) Top swage.  This will help me to form the pins of the arbor that will set in the holes on the uprights.

  3) Large V tongs.  Will be used to help make the top swage above.

  4) Layout table.  This will be critical for making the gears.  Essentially I am going to make a small, metal toped table with a pin in the center.  This will allow me to draw the size of gear I need, both inside and outside diameter.  Then, while I am forging the gear, I compare it to what is drawn on the layout table.  I need to get the gear as perfectly circular as possible.  After I place it on the arbor, I need to true it up.  The closer to a perfect circle it is before I put it on the arbor, the less filing I will have to do.


  On a bizarre note, when I came in from working I turned on the TV.  After about half an hour I felt something funny in my neck.  I pulled out a 1" wire that was stuck in my neck.  It had gone in about 1/4".  Not sure why I didn't feel it sooner but I pulled it out and cleaned the wound.  This happened with the face shield on.

More research notes...

I just received an email from a church in West Sussex.  They were kind enough to take photos of the clock that they have in their church for me.  The clock is no longer being used and it hangs in a corner of the church in the main worship area.

The clock has been extensively modified.  It has had a pendulum added to the mechanism.  This is very common and only one clock of this style still has the original escapement.  Anyway, here are some of the photos that were sent to me.

Click to see it larger.

This clock does have a different finial style then some of the other clock from this make but not that different.

This photo I have marked up to show a few things...



There are two things to notice here.  First notice the long line at the top.  This part of the clock is a windbrake.  When the clock starts to ring the bell, it is controlled by gravity.  Without the windbrake, the bell ringing would speed up.  This would cause to do something like this...    ring........ring......ring...ring..ring.ring.  Anyway, this windbrake is just under a beam of wood.  There is no way this clock could work at its current location as the windbrake cannot spin.

The other item I have marked up is the circled area of the frame.  This hole is used to hold the medieval style escapement and it has been removed.  This picture from my clock shows the hole.



I have about 10 high rez photos of the clock in West Sussex.  Still studying them...

Started cleanup...

Did a little bit of work on the clock today.  I started by correcting a minor problem with one of the end tabs.  That involved just a few hammer swings.  Next, I started to work on the cleanup of the clock.  At this stage, it mainly involves removing any left over scale.  This is more difficult then I expected. 

I had to use one of the more aggressive wire wheels to get the scale to even budge.  It is making a big difference but it is taking time.  I got about 25% of the frame cleaned up before I came in.  I did coat the newly cleaned up metal with some oil to prevent rusting until I'm ready to apply the finish.

Now, an important safety tip.  I am doing something which I really don't want to do.  That is, I am using wire wheels with an angle grinder.  The wire wheels, no matter their quality, will shoot off bits of metal from the piece and occasionally they also throw a wire.  When using these, proper protection is a must.  Full face shield, gloves, leather apron, heavy clothing, etc...  Let me tell you why.

While cleaning up part of the clock, I temporarily lost control of the grinder.  It jerked out of my hands and the wire wheel hit my apron.  It tore up the surface of the apron pretty good.  I couldn't help but think of what things would have been if I had just been wearing a T-shirt.

So, if you do ever use a wire wheel at high speed, protect yourself.

Neat article...

I'm going to have to pick up the current issue of Nature magazine.  They have an article on the Antikythera Mechanism.  This mechanism which is over 2000 years old was capable of predicting position of the sun, moon and probably the planets as well.  It is believed to be the first example of a computer(analog).  It is one of my dream projects for somewhere down the road.  I have a big list of dream projects once I get this clock done...  :)

Anyway, here is CNN's article  http://www.cnn.com/2006/TECH/space/11/30/astronomy.calculator.reut/index.html

And here is the wiki entry on it.
http://en.wikipedia.org/wiki/Antikythera_mechanism

New clock resource

I was digging around on the internet and found a church in West Sussex that has a clock that is probably from the same maker as mine.  It can be seen at

http://www.roughwood.net/ChurchAlbum/WestSussex/WestHoathly/WestHoathlyStMargaret2004.htm

On the web page, it states that the clock is from about 1660 because of the presence of a pendulum.  However, the clock was almost certainly from the same maker as the clock that I am using as a model.  Chances are the pendulum was a modification to the original clock.  It was very common that medieval clocks with a verge and foliot escapement (the actual time keeping part of the clock) were later modified to have a pendulum.  The clock in the church probably dates from about 1600.

Anyway, I sent a note to the church to see if I can get any more photos from them.

Some basic supplies.

 Today, I picked up some new wire wheels to help on the polishing on the clock.  The bigger score today was the 50# of S7 alloy steel.  The stock is perfectly sized for making hammers and other tools.  Specifically, the S7 is for top swages that I will use to create the clocks arbors (axles).

I should read more often...

After my last post I started thinking a bit, which can be dangerous.  I went through all my blacksmithing books and I am going to try another finish.  I am doing this from memory so I think it goes something like this...

1)  Wire brush frame
2)  Follow with rub down with scotch-brite pads
3)  Next, a mixture of Linseed oil and thinner with a small amount of beeswax melted in.
4)  Wipe on metal while metal is warm (not hot)
5)  Repeat one or two times to ensure complete coverage.
6)  Follow up with a polishing wax.

Like I've said before, this would not be as big of an issue if I was using wrought iron.  However, I do want the clock to last for some time so I want to make sure I have a nice protective layer.  I may also pick up some heavy plastic that I can wrap the clock with.  This is because I frequently work on the clock at demos so I want someway to transport it in the back of my truck without it getting wet.

Frame closer to being done.

Spent some more time on the forge.  I started by finishing up the peen work.  I also went back and did cleanup on all of the peens from the other day.  I needed to do the cleanup because I had left a little "wiggle room" in case I needed to adjust the frame.  The frame is very securely together now.  I cannot get it to shift at all.

Next, I straightened out one of the end pins that had gotten a little bent during the closing up of the frame.  That looks pretty good now.

Finally, I did a test cleaning and finishing of one post.  I simply wire brushed it then treated it with beeswax.  I want to see how it comes out before I continue.  I might go for a mix of linseed and beeswax to ensure a more thorough protection coat.

Then, when I got inside, I had a surprise waiting for me.  The author of the articles that I have been using as my primary source of information had sent me an email.  I've mentioned him before but this email was very encouraging.  To his knowledge, no one has ever tried to reproduce this style of clock using period techniques.  He gave me some strong words of encouragement and offered to answer any technical questions that I might have.  :) 

It pays to send emails...

In my effort to make the clock as period as possible, I have been in contact with various museums in England.  Perhaps the best move I made was to contact the British Museum several years ago.  As a result of that contact, I received a photo copy of articles by Jeremy Evans of the British Museum.  These articles have been one of my primary sources of information.

I started emailing Mr. Evans about 2 years ago.  During conversations with him, I came to the realization that I needed to learn more smithing.  I fell out of contact with Mr. Evans and when I attempted to contact him earlier this year, I found out that he had retired.

Well, I decided to try and track Mr. Evans down as I thought he might be interested.  Once again I sent a note to the British Museum and I just got a reply back.  Mr. Evans is interested in conversing more with me.  He is probably the number one person to ask questions about this clock.  This comes at an opportune moment as I am kind of stuck in understanding a few small issues with the clock.  They include:

*  The arbor of the going train (timekeeping side of the clock).  It has several parts that slide on (main gear, a few washers and the winding drum) and I cannot figure out how all of these are properly fitted.

*  There is a tension spring on the count wheel (used to control striking of the bells) and I'm not sure I understand the purpose.  Could just be to make sure the wheel stays vertical.

*  There is a spring on the main arbor of the striking train (bell ringing side of the clock) that acts as a clutch during the winding process and I'm not quite sure of its construction.

Frame nearly complete

  Today, I was able to finish forming the bottom cross bar.  I also punched the holes in the bottom part of the frame to allow the cross bar to be placed.  Once I complete the cross bar, it was time to seal the frame up.  To do this, the end of long bars in the frame are heated then peened to form a head.  This is the same as hammering over a rivet to have it grip.  This picture shows the frame in the fire to heat up a corner to close it up.



Notice the at the top of the photo, the corners furthest from the camera have already been peened over while the closer ones are still untouched.  Also notice that the part of the frame closest to the camera is held to together by twisted rope.

This picture shows all but two corners peened over.  Unfortunately, I was getting tired and my blows were getting sloppy so I decided to stop rather than mess up the frame.  This is what the frame looks like at the moment.

 

So what's left for the frame?  I just need to peen over two more corners.  After that, its cleanup time.  I will wire brush the entire frame.  I will do this using a angle grinder with a wire wheel.  This is one of the few times I let myself use power tools.  Since I have to use mild steel instead of wrought iron, I have to worry a lot more about rusting.  I will clean the frame up then heat parts of the frame and treat it with beeswax to finish it.  Oh, by the way, the frame is almost perfectly square.  There is only one spot that it is out by the smallest amount.  It won't cause me a problem which is good because I can't figure out an easy way to fix it.

Maybe this weekend I can start making gears...

A good mistake...

  I demoed at an SCA event this weekend.  Because of meetings and other activities, I did not get as much forge time as I wanted but still managed to get a lot done.

  I worked on the crossbars on the frame.  I made a mistake in my math when deciding where to place the tenons.  When I first made the tenons, they didn't have that much of a shoulder.  I was a bit disappointed with the shoulders but when I compared them to the frame I realized that both tenons needed to be moved back half an inch.  Because of this, I was able to form a much better shoulder on the tenons.

  Once I was done with the top cross bar, I punched holes in the existing frame for the crossbar.  This picture shows the top cross bar in place.  The bottom cross bar is also in the picture but I ran out time when I was working on it.  I only need another few hours to finish it.  Within the next few days, I will be permanently attaching the frame together.



This picture is a close up of the cross bar tenon.  It shows a slot that will allow another piece to be wedge into position.  Also, notice the rust on the lower cross bar.  I left it in the slack tub overnight and you can tell what was under water and what wasn't.

Two good investments

Florida presents different problems for the different seasons.  I am working out of my garage.  More specifically, when I forge, I pull the forge out into the driveway.  I work by daylight.  During the summer, I have plenty of light but also plenty of heat.  It is usually so hot that I can only work for a few hours.  Bummer...  Anytime other than summer, its cool enough but the sun sets very early.  So I end up not having a lot of time to forge after I get home from work.

Two weeks ago I purchased a large set of halogen lights on a tripod.  These things pump out quite a bit of light.  I am now able to work up until 8:30.  I never work past 8:30 to avoid problems with the neighbors.  It has really set me free to do a lot more work.  I am hoping to make a lot of progress during the upcoming cooler months.

The second investment I made was for a membership in the Antiquarian Horological Society.  This organization published a series of articles that I am using as my primary documentation.  Although the membership is rather steep (around $100 a year) it should be a good investment.  I have been thinking about it off and on for a few years but the final driving reason for it was the note at the end of the articles I have.

The articles were photocopied and sent to me by the British Museum.  Because they are photocopies, some of the pictures aren't real clear.  Well, at the end of one of the articles they stated that the articles that I am interested in are available to members on CD.  So, this morning I sent off my membership request with a request for the CD.  Hopefully I can still get the CD.

Feeling real now...

In the spring of 1996, I started working in London.  Shortly after I started working in London, I saw the clock at the British Museum that inspired my obsession.  Unfortunately at the time, I didn't know that much about making reproductions.  I say unfortunately because I lost a big opportunity in taking photos for my own use.  I made some sketches and took just a few photos.

When I returned to the states in late 1997, it took me nearly two years to learn enough about woodworking to make my first clock.  That was 1999.  I knew when I completed it that I was not overly satisfied with it.  It didn't work all that well but it was still a very cool project.



I did a few more woodworking projects and in early 2001 I made a second wooden clock.  I was much more satisfied with that one.  It worked and the wood working was much better.  I still have that clock in my house.  (The first clock was recycled for its wood.  Believe me, it was the right thing to do...)  I felt that I was ready to tackle a metal version of the clock.



At that time, I was going through changes in my life.  I pretty much put aside a lot of projects until things settled down.  In late 2002, I put together my first forge.  It was a brake drum from a truck and powered by a hair dryer for its air supply.  My first anvil was a 55 pounder from India.  That anvil dented under a stiff breeze.  It was a year after that in late October 2003 that I started this blog.

I completely underestimated how long it would take me to make the clock.  Maybe it was arrogance or maybe I was just comparing it too much to woodworking.  But I had a lot to learn.  The Mastermyr chest reproduction I did last year gave me the confidence that I would be able to make the clock.

Earlier this year when I was finally able to figure out how to make the finials on the clock.  That was a weight off my shoulders.  Once I figured that out, I knew I was on the right track.  Also, I started to make parts of the frame.  I had some success and some failures.

Just within the past month, I have been making a serious effort to make progress on the clock.  Other than the family vacation, I have been getting out at least every other day and have made very few (know on wood) mistakes.

I sat down after working tonight to relax.  When I sat down, I started thinking about it and I realize now that this clock will be made.  There are times that I have doubted myself over the years but that is in the past.  I know I still have a lot of challenges ahead.  The axles and gears I'm sure will be challenging.  However, I have no worries about them now.  Just another technique to learn.  It feels really good.

Tonight I worked on the cross bar again.  I started to punch and cut the shapes needed on the top cross bar.  This is what it looks like.  It was still wet from quenching when this photo was taken.



A little explanation.  This cross bar will be on top of the clock.  The two cutout shapes on the right side of the picture will hold vertical bars.  A small piece of metal will hold the bar in place.  The picture that follows helps to explain it.  The blue square is where the bar will go.  The yellow bar is where a shim of metal will be placed to keep the bar in place.  The hole out the to left is to hold another part.  That part will hold a part of the clock that is similar in function to a pendulum.

Steady progress...

A few more hours of work today and the other cross bar is cut to size.  If I can get just a few more hours of work in, I should be a be able to complete the frame this weekend!

Side by side comparison...

  A little bit more work on the forge today.  Finished cutting one of the crossbars.  Not too exciting but here is a side by side comparison picture.  The metal on the left is the 4" x 3/8" stock that I am cutting the crossbars from.  The bar in the middle is the cross bar I just completed.  The one on the right is a crossbar I made early this year.



  The bar is not yet completed.  There is some additional work necessary but the rest of the work won't be as monotonous as the cutting.  I just have to punch a few holes and make a few small cuts.

Cross Bars Part Deux

 A while back I started work on the cross bars.  The cross bars sit in the middle of the clock and are used to hold vertical supports for the axles.  When I made them, they have a bulge in the middle but the bulge really wasn't wide enough.  Here is a pic of the original cross bars.  This is an old pic of the frame from many months ago.  The cross bars are in the middle of the frame just resting on the frame to give an idea where they sit.



I started to make the replacements for these parts.  I am using a piece of 4" x 3/8" flat stock.  Here is a picture of the piece prior to any work.  You can see markings that am using to make the piece.  To make these pieces I am chiseling rather than drawing out (thinning) the thin part of the bars because it is easier.  Anyway, this is the pic.



There is a bulge in the middle with thinner arms to either side.  This is a picture after some of the chisel work.



Unfortunately, some storms were threatening and I needed to take care of some stuff for work so had to stop for the day.  Here are some other pictures.  This is the bending fork (or scroll fork) that I quickly made yesterday.



I also picked up some steel today to make a cutting saddle.  The cutting saddle is so that you can safely chisel through your metal.  If you did not have one of these and you accidentally cut all the way through the metal, then you would dull your chisel on the anvil face (or scar your anvil if its from India or China).  I made a saddle a while back but the metal was too thin and it distorted whenever it got hot.  The new one is much thicker.



After I formed the saddle, I made sure to make the saddle dead soft.  That means I heat it to a nice red head then cool it very slowly.  This makes the metal very soft and less likely to ruin any chisels.

Prep work for the gears

Got out to the forge for a few hours.  For tonight, it was tool making night.  First, I made another large chisel.  I then used that chisel to make a bending fork.  The bending fork I will be using to form the circular part of the gears.  To make the bending fork, I split a 1" bar stock for about 6".  This split was then bent and seperated to form a "T" shape.  After I rounded up the arms I bent them back into a "U" shape.  Overall, to make the chisel and fork was less than 2 hours of forge time.

End pins complete

Got out to the forge for a few hours today and I managed to finish the remaining 3 end posts.  Really starting to feel like things are moving along now.  If I am lucky, I may be able to complete the frame next weekend.  After that, get to start actually making gears!!!

End pins, 1 down, 3 to go.

After taking a break from the earlier blacksmithing, I decided to do a bit more work and managed to get the first of four end pins made and installed on the frame.  These pins are used to hold vertical frame pieces that the axles for the clock rest on.  They are just simple tabs that the end pieces will be attached to using a wedge similar to what I used for the strike arm supports.  Anyway, here is a pic of the end piece prior to cleanup.  It is the middle of the bar on the left side of the picture.  Also, the wedged strike arm support can be seen on the right side of the picture.

Some blacksmithing today...

Today I managed to attach the two strike arm supports to the frame.  This involved slitting and drifting two holes on one bar of the frame.  After I made the holes, I also had to reshoulder the tenons.  This is because the process of drifting the holes lengthened the bar.  Anyway, this is a picture of the two striking arm supports on the clock.  Notice that one of the supports is wedged so that it can be removed.  This is to allow me to make the strike arm at a latter time then put it on the clock.  Anyway, here is a pic of the frame with the support arms in place.

Another part down...

After being at the Florida Convention yesterday, I could not resist doing some blacksmithing today.  I decided to make the other strike arm control.  I made about a week ago and it came out fairly well.

 

The one I made today was the same with one notable exception.  This one would need a slot in the tab.  This is so the part is removable.  One of the two arms needs to be removable so that the part they hold (the strike arm) can be removed and worked on.  I took more photos to show the creation process.

This first picture shows using half hammer blows on the 3/4" stock to start forming the round end on the bar.  The hammer is struck so that half of the hammer is over the anvil and the other half off of the anvil.



This photo shows widening the arm to give it a slight tapered shape.



Using a square punch, a hole is made for the piece that will hold the support to the frame.



Next the piece to hold the arm to the frame is made from a piece of rectagular stock.



A tenon is formed on the stock.  A rectagular hole is punched and drifted.  Finally the piece is almost cut off but not quite so that it can still be worked with easily but when the time comes, it will be easily snapped off the stock.  Also visible is the pin that will be used to hold the piece onto the frame.



This shows the pin in the mortise.



On the round end of the piece, I start by punching a small hole.



This hole is drifted open some more...



Finally, the end is rounded up with the drift in place.  Sorry for the out of focus.



The two pieces side by side.  I will need to stretch one of them by about 1/4".  Not a big deal but it was too dark to continue working.



Both pieces need to be touched up and filed but they are pretty much done.  After the family visits for vacation, I am going to try and work more consistantly on the clock.

Florida blacksmithing convention

  This weekend was the annual Florida Artists Blacksmith Association's annual conference.  I took some pictures which I may post later after looking through them.  Some of the highlights...

  * Replenished my coal supply.  Bought close to 1000 pounds of coal.
  * Purchased a small cone mandrel and round bottom swage that both fit my anvil.  The bottom swage will help with the clock as it will help to make some of the axle parts.
  * Watched a blacksmith by the name of Elmer Roush most of the day.  He enjoys doing historical reproductions including viking locks.  I definitely enjoyed talking with Elmer.
  * Someone brought an 18th century spit jack.  A spit jack is a mechanism for automatically rotating food.  It is weight driven and dates back to the later middle ages.  Certain construction techniques on the spit jack are very similar to the clock.  I took a few photos.

  Probably won't hear much from me for two weeks.  Spending time with out of town family at Disney and the beach.

Strike Control Arm continued...

  I was able to continue to work on the strike control arm today.  I punched a hole in the top part of the support that will hold the strike control.  I then attached a small piece of metal that will be used to attach the support to the frame.  Here is a picture of the finished piece.



For sense of scale, my anvil is just 5" across the face.  The tab at the top of the photo will be put through a mortise in the frame.  It will then be peined over to attach it.  It really felt good to make a part that isn't necessary just part of the frame.  Its something that will actually be in contact with a moving part.

I also was able to try out the char cloth that I made yesterday.  It worked perfect.  I think about the third spark caught on the cloth.  It starts as a tiny red spot.  As you blow, it spreads outward in a glowing circle.  I was able to start my forge in under one minute using flint and tinder.

As I shut down the forge tonight, I produced another batch of char cloth.  This picture shows the metal container I use for the char cloth.  There are a few small holes poked in the can.  The burnoff of the impurities shows up as smoke coming out of those holes.

Char cloth

  Something else that I did while working on the forge was make a good batch of char cloth.  One of my longer term goals has been to create a truly period setup for my forge.  A while back I mentioned that I learned to start fires using flint and steel.  The material I was catching the spark with was steel wool.  Steel wool burns incredible easy.  The period alternative is char cloth.

  Char cloth is essentially cloth that has been "cooked" to remove all the impurities just like charcoal is charred wood.  I took an old T-shirt, put the pieces in a metal container and kept it near the center of the forge while I worked.  I tested the cloth late last night and it worked perfectly.  This was much better than a batch I made a little while back.

  The neat thing about char cloth is that it "catches" a spark.  You see a small red glowing spot.  As you gently blow, the red spot slowly grows into a circle.  Then when you blow a little harder, it produces enough heat to light tinder that is near it.

Strike Control Arm

Work has been way too busy and the anvil has been way too quiet...

  Today marked the first time in about 4 weeks that I've gotten to the forge.  It was only for a little over an hour but I worked fast.  I began work on two parts that need to be attached to the frame before I can permanently fasten the frame together.  These two parts are used to hold the strike control arm.  The strike control is used to connect the time keeping side of the clock to the bell ringing side of the clock.  By the way, the technical terms are the going train (time keeping side) and striking train.  This picture shows the location on the original clock.

  I started with square stock that was 3/4" x 3/4".  Work went very fast even when I had to stop to make a drift.  I stopped for the night when it started to get dark and I needed to make a new punch.  This photo shows the mostly complete part.  It just needs to have a hole punched and a little shaping.  I was really surprised how fast I made it.  Anyway, this picture shows its approximate location on the clock.  Where I am holding it is actually about an inch lower than the final position.  On the picture, you can also see the pip marks in the corner of the frame used to help me reassemble the frame when needed.