I am now trying to tick of all the things I have to do which is listed in my Appendix 14. "Make a really nice design" is one of them. So before I could start making the final designs I made a rough sketch of how I want it will work. This was my first try:
Then I started to do some mathematics and tried to figger out how many teeth each wheel needed. I started with the once labeled A, B, C and D below. The once which make sure the hands turn exsactly 12 times quicker/slower.
After doing some doodling on a page I figgered out that the ratio should be 48:12:36:12, so
A = 12 teeth
B = 36 teeth
C = 12 teeth
D = 48 teeth.
Then I looked at the diagram in the book a bit closer, and saw that they just gave the answers in the book. Just a bit different.
A = 10 teeth
B = 30 teeth
C = 6 teeth
D = 24 teeth.
I checked and found out that both are possible. They will both work, I will just more likely use the one shown in the book because the bigger wheels will be smaller, and therefore hopefully easier to make. Then I compared the ratios to the wheels, and found that the wheels were in the incorrect position. So I made my second sketch design.
The reason why I didn't make the A, B, C and D set in a square formation like the diagram is because you then had to get the minute hand through the hour wheel which would be extremily difficult to do, so this way it will be easier, more visual, more accurate and more artistic. Then I looked at the full page where I got the diagram from, and saw an easier way of making the pendulum and weight.
So I made a third sketch based on this discovery.
Then I thought that the pendulum goes left to right approximately once every 2 seconds. So if the pendulum has 30 teeth. The minute hand becomes the second hand and the hour hand becomes the minute hand. You can solve this problem by giving the escape wheel 1800 teeth, or just by adding more wheels. From the minute hand to the hour hand we solved it down exsactly 60 times. So why don't we just repeat this. This gave me my fourth sketch.
I also thought that if the escape wheel turnes once every minute, you can just as easily attach a second hand on it, for the clock to not only show which hour and minute it is, but also the seconds. On this sketch I also wrote down how many teeth each wheel has to make it less confusing.
The next problem I found was that I am now assuming that the pendulum will go back and forth every two seconds, but I can't assure that. My dad helped me with that, and said that the pendulum is just like a metronome. I have a metronome at home and it can go from 40bpm to 208bpm. So if it's on 40bpm it will go give 40 click every minute. When you move the weight on the pendulum up or down it changes the speed of the pendulum. The further up it goes, the quicker. The further down you move it, the slower.
For the clock I choose 30 teeth on the escape wheel, because it doesn't matter how many teeth the wheel has as long as the wheel it is attached to has the same number. Like in the sketch, the wheel the escape wheel is attached to, is also 30. So I could have choosen 60, when the pendulum has to go back and forth every second, or I could have choosen 15 when the pendulum has to go back and forth every 4 seconds. But I choose 30 to not make it go too quick, but not too slow for the results to become inaccurate.
Every time the pendulum goes back and forth once, one teeth will have escaped. So because there are 30 teeth, and it takes two seconds for the pendulum to go back and forth, the whole wheel will turn one whole round every 60 seconds.
To make sure the pundulun goes back and forth exsactly once every two seconds you just have to play around with the height of the weight on the pendulum.
A few days later a friend of mine wrote a comment suggesting that I could use the verge escapement instead of the anchor escapement I am using now. I did some research on different escapement and found that there are lost of different escapements you can use. But the verge escapement this person mentioned I made a design which would use this, and I concluded that I will stay will my achor escapement, so my fourth design.
Emma,
ReplyDeleteWhat you describe is an anchor escapement (see wiki), probably discovered by Robert Hooke, and used in clocks to make them more accurate. In earlier clocks Verge escapements(see wiki) were used. They were easier to make, but less accurate. As accurateness is not the goal of your project, i would advice you to use a verge ecsapement.