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Thursday, 14 February 2019

A chart for discovering Woodenclocks features.


There was a time, not so long ago that I could remember the details of all my clocks, but sadly there are now so many that it becomes progressively more difficult to do that. So if I am having trouble remembering details of all the clocks I realised that it must be twice as hard for you to make choices of the clock you want to make for yourself.
With this in mind, I have put together a chart that tries to list all the relevant information about each one so as to make your choice a little easier.
The chart is actually a PDF file that was created in Excel with each clock listed down the first column and the relevant feature information in the following columns.
You can download the file by clicking here.

Notes on the chart.

The first column, Made From indicates the material that the clock was designed to be made from, the great majority are designed to be made from hardwood and an earlier post on that topic gives you some help choosing the most suitable for your clock.
The choice, of course, is not limited to just wood, you can construct these clocks from metal or plastic as well, and many people have already done this, but wood is the most popular choice, after all, it is a wooden clocks website. There are some exceptions to this, and these are the 5 clocks designed and intended to be made using 3D Printing. These clocks are not supplied with DXF files for CNC machining but use STL files instead for use with a 3D printer. These were originally intended for the use as prototypes for me when developing the clock designs, but have proved to be popular so they are now included in the portfolio of clocks.

Third column Units indicates whether the clocks were designed in mm or inches, all clocks from Clock 9 onwards are dual dimensioned in both mm and inches.

The fourth column indicates the degree of Difficulty in building the clock. This is usually down to how complicated certain parts or assemblies are actually to make If a clock can be made entirely using the CNC machine and hand tools then it is easy. Even Easy clocks are not really simple, clocks to work continuously and accurately still take a lot of time and patience on your part so be prepared for a challenge.

With the Intermediate category, we have the clocks that are a little more complex and will have bearings and ground steel shafts to provide more precision in the clock. You may also need to find some slightly more difficult assembly operations that need to be carried out.

When you get to the Hard clocks it's just more of everything that the others have and you probably need some better equipment like a lathe and pedestal drill.

There are a couple of Very hard clocks that both have a quite complicated build requirement and lots of fine adjusting to get the clocks to run and keep running.

The Longest Part column gives you some indication of the size of the finished clock, in each case, it will be the length of the Back frame of the clocks.

The Pendulum Length column gives you an indication of how fast the clock will tick, a length of 990 mm will do a tick-tock in 2 seconds, and a 250 mm length will do it in 1 second. So the shorter the pendulum the faster the rate. An earlier article on the subject of Pendulums explains this in more detail, see link below.

The Weight needed to run the clock continuously will vary dependent on the quality of the build, the more friction in the working gears the more weight you will need. My clocks being prototypes are generally speaking a little rough around the edges because of the change that gets made to the parts to get them to work in the first place. So you may well find that your clocks will need less weight to keep the clock running, you can only find this by experimentation.

The next column lists the Run Time, it is based on my experience with the building of the prototypes and can only be used as a guide, there are a lot of factors that can affect the running time, not least of which is the height of the clock above the floor, or more precisely how far the main weight will drop from fully wound to when it hits the floor. For the times listed in this column, I had the clocks mounted so that the centre of the dial was 1500 mm above floor level if your clock is mounted at 1650 mm then you will increase the running time by 10%. There are several ways to increase the run time, you can add a simple Pulley arrangement to double the run time but this will also require you to double the weight. The letter P adjacent to the run time in this column indicates that this clock was designed with a pulley built into it. There are other ways to increase run time, one is to reduce the diameter of the Drum so that less cord is let out with each rotation of the drum, but again this doubles the weight.

The final column Escapement tells you what type of Escapement is used to control the ticking of the clock, the simplest and most common escapement is called The Graham named for its inventor, this is a dead beat type escapement that halts the rotation of the Escape wheel at each Tick and Tock, a simple design that works really well but not the most efficient design because of the friction involved. The Gravity Escapement overcomes most of the areas of friction experienced in the Dead beat design, the design used on these clocks which I call the Woodenclocks Gravity Escapement was design specifically for use on these woodenclocks it is a more complex escapement but it does result in more efficient clock design. The Verge and Folio is one of the very first designs to be used in the very early clocks, it is visually quite interesting but not very accurate. Then there is the Grasshopper a very elegant design invented by John Harrison back in the 18th century, it is actually quite hard to get it going, needs a fair amount of tinkering. Finally the Flying Pendulum, this is definitely one of a kind wonderful to watch it working but not very accurate.

References

Wood for Wooden clocks

https://brianlawswoodenclocks.blogspot.com/2013/01/materials-for-wooden-clocks.html

Simple Pendulum

http://brianlawswoodenclocks.blogspot.com/2014/03/simple-pendulum.html







1 comment:

  1. Very helpful table.
    I wonder why you did not use the grasshopper escapement in more clocks.
    It is the quietest and the most enjoying for the eyes. very low friction and reliable.

    ReplyDelete