Plan of attack...

Now that I've managed to make my first gear, I needed to stop and take a look at where I am at with the project to decide how to best proceed.

The problem with building a clock like this is that the parts must interconnect with very little room for error.  In making the main gear like I did, I probably did not leave enough room for the verge, foliot and crown wheel (the medieval version of the pendulum).  I could make adjustments on the current setup but I think in the long run, it will be better to remake the gear.

Not to worry, I think next time around I should be able to make the gear over a few days.  In fact, if I am disciplined about it, about 14 work hours are needed to make the gear.  I am feeling freshly motivated to get going on the project.

So, what am I going to work on next?  I think this will be the new order...  I am mainly putting this here just as a way to force me to think about what I should work on and in what order.

* Remake the hanger for the verge and foliot.  I want to make this look more like the original one of a clock from Dover Castle.  This should take an afternoon.
* Make the bottom holder for the verge and foliot to the center part of the frame..  This is a small piece of metal that keeps the verge and foliot straight as it "ticks".  This should be about 2 hours of work.
* Create the verge and foliot.  This is essentially a "T" shaped piece of metal.  There are some things I need to figure out with it.  I am thinking about 2 sessions at the forge.
* Create the end arbor hole in the center frame.  This is a "U" shaped piece of metal that wraps around a verge and foliot and holds the end of the arbor that holds the crown wheel.  This should be an afternoon worth of work.
* Make the crown wheel.  About 2 sessions at the forge.
* Make the crown wheel arbor including a temporary placeholder for the gear that will contact the main gear.
* Remake the great wheel and arbor.
* Make the winding spindle and clutch for the great wheel arbor. (This makes sure of the spacing on the arbor).
* Make the smaller gear on crown wheel arbor that contacts great wheel.
* Make permanent weights for verge and foliot.  The weights allow for fine tuning the clock if it runs too fast or too slow.  I will use temporary weights until this point.


When all of that is done, the clock should keep time.  I know this seems like a lot.  However, after finishing this test gear over the weekend, I have renewed confidence and energy.  The only thing that will slow me down is that I can only work on weekends with the days being so short right now.
 

Looks like a gear

Today was a good day...  I worked on the forge for about 4 hours today and managed to get all of the waste material popped out.  After a few tests, I was able to work on three teeth per heat.  I would heat the piece and chisel three of the teeth from one side, reheat and then chisel from the other side to finish getting rid of the material.

This is at about 1/3 of the way done.



Chisel from one side.

(Notice the can hanging from the anvil.  Makes for quick cooling of the chisel between teeth.)




If you look carefully, you can see that after using the chisel on one side, the material has been forced out some.


Chiseling from the other side and the tooth easily pops out.



And then finally, I could not resist putting it in the frame to see how it would look.





  And once I got into the rythm of cutting the teeth, it was a very easy operation.  Most of the time spent today was just waiting for the piece to heat up.  I cannot say for sure that this is the way they did it in the middle ages but I have yet to see a faster or easier way to do it.

All cut...

Well, all the gear teeth have been cut...



Tomorrow I am going to try and start popping the teeth waste out.  I think that will go faster and be easier on my arm than the sawing.  I am really looking forward to this step.

Things to note about this gear.

* I've mentioned before that the gear may not work because it has a few slight problems.  If that is the case, I'm not too worried.  I had always expected that the first gear would be a throw away.  It does not mean that I am not going to try and make it work just that I am prepared for it to not work.

* I need to get better about having a nice smooth, finished surface before I start trying to mark out and cut the gears.  My biggest problem with cutting was that the lines marking the cut points were not nice and clear.

* A divider (compass) works perfectly for laying out the teeth.  An article a few years back in the Antiquarian Horological Society had suggested some alternate techniques.  Quite honestly, the techniques are overly complicated when the divider method works just fine.  I have to disagree with the author on some of his suggestions.

* Overall, it takes about 15 minutes to cut 4-5 teeth.  This means that if I was a full time smith and my arm was able to take the sawing, the largest gear could have been cut in about 5 hours.  I am sure if I was practiced and once again in the proper shape, that time may be cut down to about 3 hours.  I think that this technique was probably the most likely technique used.

* I went through about 3 saw blades to cut this one gear.  However I think the steel may have been partially hardened in a few spots.  If I was using period materials, the saws would not be as high of quality but the gear would be wrought iron which is very soft.  I have some wrought iron and I may do some testing to do a comparison.

* In the future, from my new experience, I would expect to be able to produce the gears much faster.

Finally a real update...

   After taking care of a bunch of stuff around the house and at work, I finally got some time in on the clock.  On the main wheel, I am almost complete with cutting the sides of the teeth.  I've got about 75 of the 100 teeth cut.  I am going to try to finish them tonight.

  To give an idea of how much cutting is involved, I am cutting 100 teeth to a depth of about 1/2" in about 3/8" to 1/2" thick stock.  So taking 100 times 1/2" times 2(two cuts for each tooth) is about 100 inches of cutting so hand cutting over 8 feet through about 1/2" stock.  It would not be so bad if it was one long cut but I have to carefully start and angle each cut.

  So far I am fairly happy with the gear.  Once I start actually punching the teeth out (I hope tomorrow if the wind dies down) it should go much faster and I should feel better about it.  At that point I will have crossed (in my mind) the finally threshold in getting the clock done.  Even if this gear does not turn out well enough to actually use, I know have the skill to do everything I need to do on the clock.  It is only a matter of time.

  Pictures will follow in the next few days...

Long hiatus

  I must apologize for not doing regular updates recently.  Work has been very busy and is finally tapering off.  I was taking some professional certification tests for work and I was spending a lot of my free time studying.

  What little time I've had free has been put to some good use.  I helped a co-worker clean out his father in law's garage.  Part of my reward for doing that was that I got some tools cheap.  In all honesty, I have not had a chance to go through them all yet but this is a partial list.

  * Wood joiner (about the last major piece of woodworking equipment that I did not have)
  * Drill press.  Nice one.  It is pretty much a duplicate of the one I own but I will be able to setup one of them as a full time mortising machine for woodworking.
  * Craftsman tool cabinet with tools inside.  This is one of those big rolling tool cabinets and it still has quite a few tools in it.  I still have not had a chance to take an inventory.

  As a result of the new influx of stuff, the shop is currently a mess.

  I am taking two weeks off for the Christmas season.  I hope to get some shop time and hopefully get back to the clock soon.  I have not made nearly enough progress this year.  Hopefully next year will be better.

Been pretty busy...

Greetings all,

  I have not been able to work much on the clock recently.  Between work and going to a blacksmithing convention last weekend and doing a boy scout blacksmithing demo this weekend, not much progress.  I'm hoping to get some work in this week.

Just a quick post...

Unfortunately, due to work and Halo 3 (mostly Halo 3) I have not gotten as much done as I would have liked to over the past week.  However, I am thinking of taking a few days off next week just to get some smithing time in. I have about 1/2 of the teeth cut at this point.

On a note related to that, I am expecting that I will have remake the gear.  I, in many ways, was fully expecting that before I even started.  My experience has shown that when creating a more complex part for the first time, it takes several attempts to get it right and there are a few things about this gear that may not work.

So why am I proceeding?  Quite simple, gear cutting practice.  If I screw up this gear, no problem.  It gives me a chance to really perfect my gear cutting.