Sunday work

  Sunday started with some more work on the hub.  Essentially I had to draw out the arms of the spokes, straighten them in a perfect "X" and punch the hole for the arbor.  Finally, I had to create small tenons to connect into the outer part of the Crown Wheel.  Not much here to show that I haven't shown before.  This picture is just prior to forming the tenons.

Next, on the crown wheel I had to punch the holes for those tenons on the spokes.  I messed one of these (made it too big) but was able recover from it.  The really difficult part here was to force the spokes into wheel.  This really took a lot of muscle, hammering, clamps, etc...  to get it into place.  In the process, the wheel became slightly distorted.  I think I can do some corrective action.  Hopefully the wheel is still in good shape.  This picture shows the spokes in the wheel.



Finally, some pictures of the nearly complete wheel in the frame.





The main problem with the wheel is that the arbor is not perfectly perpendicular to the wheel.  This causes a wobble when the wheel is spun.  With my experience of the great gear, I know I can correct this to some degree.  Hopefully it will be enough.

Even if this wheel does not work out (I hope that it does!), the important thing for me to remember is that I created this in under two days.  If you look back in my blog, when I first attempted the great wheel, that was over several months.  My experience level is getting to the point where I am much faster, more confident, blah, blah, blah...  :)  I will beat this project yet...

Some more work on Sunday...

  I did get in some more work on Sunday.  However, I have not had a chance to upload photos yet.  I will do a longer entry this evening.

Good progress day...

Today I wanted to get started on the crown wheel and I was able to make good progress.

I started with the hub of the wheel.  This is just like the hub I did for the test great wheel I did months ago.  The metal is split into a "Y" shape and stretched out.  Then it is flipped around and repeated.

This is the last photo of the hub that I took.  I wanted to hold off on finishing it to make sure it would work with the crown wheel.

Next I turned to the crown wheel.  The crown wheel has a diameter of approximately 8" with 33 teeth.  Something of an interesting note.  An article that I have used for a lot of my source information had some interesting theories on how you would lay out 33 teeth.  He believed that since the number could not be easily split into halves that it would be difficult to layout with a divider.  He had some interesting theories on how you could layout the teeth.

In reality, it was quite easy with the divider.  I divided by 11 then divided those by 3.  I started by laying this out on a straight bar.  It was about 1/8" thick by 1 1/2" (I think).



I then removed the waste with a hacksaw.  Because of the thinness of the metal, this was fairly easy.  I am still a little bothered that I don't have more evidence on using hacksaws but it seems perfectly logical.  Medieval hacksaws do exists and they could easily be made to be hard enough it is just that I do not know of any woodcuts, manuscripts, etc...  that show a smith using a hacksaw.



You may notice a little tab on the end of the stock.  I was originally going to rivet the wheel together but I decided to braze it instead so the tab was cut off.  After cutting the metal, I began to curve it into shape.  This shows the crown wheel in the fire.



Finally, after curving the wheel, I took a photo of the crown wheel with the verge and foliot just to see them together for the first time.  The tabs are not yet on the verge and foliot and I haven't placed the hub in the crown wheel.  Also at the bottom of the photo, you can see that the crown wheel is not yet welded together.  I want to hold that off until I get the hub in the crown wheel to make it safe.



Finally, a picture of the crown wheel on its own.  I did double check and when it is brazed together, the teeth are perfectly spaced  (probably no more than 1/32" inch variation.)

Clockmaking weekend...

  I have tried to clear my schedule for this weekend.  I am going to make the serious effort to do the crown wheel this weekend and get the clock ticking.  At this moment, I don't have any commitments either personally or professionally so I am really hopeing to get a solid 2 days of blacksmithing in.

  The key right now for me to work on the clock is simply time at the forge.  I truly feel that I have all of the skills (although I am sure I will make plenty more mistakes.)  I've also noticed that over the past 6 months in particular that when I do work at the forge, I have a lot more confidence and that I am working much faster.

  I may try to get some evening work in as well this week.  With summer coming on, there are a few hours after I get home that I can work.

More of a note to myself...

  I am hoping to get started on the Crown Wheel next week and I was just mulling over an issue I had with the wooden version of the clock.  Before that, a reminder of how the crown wheel and verge and foliot work together...  This is taken from the Wikipedia entry for Verge and Foliot

  In my clock the Crown Wheel will be turned 90 degrees from what is depicted here.  In other words, the arbor will be horizontal rather than vertical.  It will also have 33 teeth.  In addition, the verge and foliot (the bar in the top of the diagram) will be vertical rather than horizontal.  The way this works is that as a weight turns the crown wheel, it catches one of the pallets (letter q in this picture) and that rotates the verge and foliot.  Then, just as the Crown Wheel rotates one of the pallets out of the way, it catches the other pallet and it has to rotate it the opposite direction.  This repeats over and over.  So the Crown Wheel is always trying to rotate the same direction but to do so, it has to rotate the verge and foliot one direction, then the other.  This oscillation is the "tic toc" of a medieval clock.

  Anyway, in the wooden clock that I made, I had a lot of trouble getting this to work.  The problem was that sometimes it would jam or skip teeth in the Crown Wheel.  Sometimes the pallet would not swing into place in time or it would swing into place too early.  Fine adjustments with sand paper was required to get it to work properly.  Even then, variations in humidity affected this.

  I think when I made the wooden clocks, I was trying to have the pallet engage the Crown Wheel as soon as the other pallet released the Crown Wheel.  In other words, it would already almost be touching.  I think the solution is quite simple.  I am going to try to design it so that there will be a significant gap (maybe about 1/8 to 1/4 inch) when one pallet disengages to where the next one engages.  This should cause a suddenly slip in the Crown Wheel as it rotates that gap to engage the other pallet.  It will also lead to a more distinctive ticking.

  If you don't understand this, don't worry.  I just made this note because I've been mulling this over and I wanted to get it down on paper and make myself think it through.
 

Good to be working again.

Well, work and health issues kept me from the forge but I finally got a full day in today...

Last time that I did serious work on the clock, I had been playing around with the crown wheel arbor.  The crown wheel together with the verge and foliot perform the medieval version of the pendulum.  They help regulate the running of the clock.

Well last time I work on the clock, I noticed that one of the frame pieces had a few problems.  I had punched the crown wheel arbor a little off center (not that big of a deal but visual distracting) and I had also placed it a little too high.  Also, the mortises for the piece were a bit too far apart which meant that the piece had to be convinced to get on the frame by using a hammer.  Luckily this particular piece is not permanently attached so I decided to go ahead and remake it.

I started by punching the lower mortise on the piece.  This was done using a simple rectangular punch.  Next I needed to drift the hole for the great wheel arbor.  I took this picture because I wanted to emphasis one of the benefits of traditional blacksmithing over metal fabrication.  The frame piece is about 1 1/4" wide while the hole needed was 1".  If I simply drilled the hole, there would not be enough metal.  If you look at the following picture, you will notice the circle drawn on the piece.  This shows how little metal would be left.  The top piece is the new frame piece while the bottom piece is the old, bad piece.

 

To start, I make a small slit in the piece that is the same as the diameter of the hole.



This is drifted using progressively larger drifts until the desired size is reached.


After the great wheel arbor is complete, I move to the crown wheel arbor.  In the top part of the photo is the piece of the frame that is in the middle of the clock.  The lower piece is the new piece and it goes on the end of the clock.  On the top piece, the arbor hole is actually in the "U" shaped piece of metal.  The reason for this will be obvious in the last photo for this entry.

Note that the great wheel arbor holes (right side of photo) are different sized.  This is intentional because of how the great wheel arbor is constructed.


The crown wheel arbor is punched then drifted.  This just shows the punch.  I forgot to take a photo after drifting.



This picture shows the old frame piece.  Notice the white lines.  I marked it to show how much the mortise needed to be shifted.  I then used those measurements to finish up the new piece.


After completing the frame piece, I then did some cleanup on the crown wheel arbor.  I had worked on it some in a previous session but it need some cleanup and a little reshaping.

In this final photo, I wanted to show the placement of the crown wheel arbor and the use of that "U" shaped piece of metal.  The crown wheel arbor is located just above the gear.  Notice that the left side of the crown wheel arbor rests inside that "U" shaped piece of metal.  The verge and foliot extends down through the clock and it can be seen between the "U" shaped metal.  So that "U" shape allows for the correct placement of the verge and foliot while also giving the arbor somewhere to rest.

I am still going to try to get the clock "ticking" by the end of the month.  It is important to me to feel like I've made progress.  Essentially this means I need to make the crown wheel and put the pallets on the verge and foliot.  I hope that this can be done with a few evenings worth of work.