Wednesday, April 17, 2013

Finishing a clock (literally)

The time has come, the walrus said, to speak of many things (Lewis Carrol, The Walrus and the Carpenter). And now we have to put on a spurt of effort and actually finish the thing. Literally. Among the major projects done since my last post, the biggest is the minute work. Clockspeak, of course. In my case this is a misnomer. The Center Wheel revolves at a majestic rate of one revolution per hour. Great thing for a minute hand! But, as you will immediately see, this is not really cool for the hour hand. In one hour, given our 12-hour dials, the hour hand has to go round 1/12 the distance. (12 hours in one half-day). So what to we do? Add more gears, of course. Now I had cut these gears on the bandsaw long ago. But now we have to depth the wheels and pinions.  Clockspeak rears its ugly head again. Remember, big gear is a wheel, small gear is a pinion. Depthing means make them run freely. Book recommends sandpaper. I found a better way. Mr Wilding didn't know about Dremel tools or he would have done this himself. Book published in 2002 or so.
 So I did something I should have done long ago. Live and learn. I measured the aperture between gear teeth, and it is close to or exactly 3mm. I searched my inventory of Dremel tool accessories and found a router bit very close to 3mm. I put the wheel into the Taig and the Dremel into my vertical milling attachment. With this setup I could shave 0.01 mm off the teeth, and shave them I did, running the Dremel at max. Saved hours of work. I used my 60-hole dividing head to position (index) the teeth. Forget sandpaper. It was very nice that these things are 30-tooth gears; my 60-hole dividing plate can handle them easily. Pinions done same way; again they fit my 60-hole dividing plate.

This bit done, the we are almost through the major work on the clock. So the big moment has arrived. The clock was taken apart. If you make a clock, you will soon learn that the fate of a clock is to be taken apart. I handed the clock over to John. He is to make it look pretty. He is very, very, good at that.

 Gulp. The paper patterns have been sanded off. I feel lost without my paper patterns. But go they must. So John got rid of them. My only spec was that the various wheels should have different colors. Here, John is staining the Center Wheel. Previously he has sanded it. Gone is the paper. Again, gulp.
 The plates look very nice in a much darker color. They have a certain character.
There are many details with which we have to deal. But amazing.  A piece of very cheap plywood turns out a very nice clock.

Endless details. I have to smooth out the escape wheel. I have to make the pendulum...  never mind. Progress is progress.

While all this is going on I am setting up to make my next clock. It will not be a wooden clock. And that is all I will say at this point. But clockmaking is not a hobby. It is an obsession.

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