Clocks, Watches/Clock Bob weigt

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Expert: - 11/29/2009


Question
I'm in the process of making a wooden clock.The pendulum is 1 meter long with a bop of odd chap filled with lead shots.I don't have any lead shot
and like to make a simpler shape bob,Can you tell me what the weigt is to be I'm using a wooden rod to suspend it.

Regards  Bernie

Answer
Bernie, in designing a clock, the weight of the bob should be light enough as to not stop the clock by being too much for the power of the mainspring or weights.  It should not be too light as this will cause an erratic timing.  There are books that have equations for this, but there are many factors that have to be known concerning the gearing ratios, torque of the gear train, and the required pendulum swing to result in a proper escapement function.  I have never designed a clock in this manner that would require pendulum bob calculations.  Most that I work on are similar to other clocks of some type that I can test a similar bob that will work satisfactorily.  Sorry I could not come up with a good answer for you.

John Newman
THE VILLAGE CLOCKSMITH
Old Prattvillage
Prattville, Alabama

Clocks, Watches

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John Newman

Expertise

As much as I would like to offer values of clocks, I am not a certified appraiser and will not venture into giving an unresearched guess. There is very little published information on what I consider to be the value of "modern production clocks". Considerations are what the clock originally sold for, the condition of the case and movement, and particularly the area in which you live, the demand and the economy. ALSO, WATCHES ARE NOT MY FIELD. However, I can advise the clock owner on proper maintenance of a clock to keep it running, small corrections and adjustments and how to move a clock without damaging it. I can also advise on obtaining parts for clocks. It helps if you can send any information on the clock movement which is usually found on the back plate of the movement. I have been a clockmaker for about 35 years and was plant engineer in the mid 90's and later operations and engineering consultant at Emperor Clock Company in Fairhope, Alabama. I now have my own clock shop.

Experience

One of my greatest accomplishments was traveling to China to assist a clock factory in building clocks to the standards which we required. With the proper specifications and quality control, some beautiful clock cases were built. The factory people from the wood carvers to the plant manager were very congenial, friendly and I left a lot of wonderful friends when I returned from my trips.

Organizations
Chamber of Commerce Small Business Committee

Publications
Horological Times, a publication of the American Watch and Clockmakers Instute. Collaberated column author, with Photos and ideas for clock movement conversion article.

Education/Credentials
Associate of Science Mechanical Engineering Technology Emperor Introductory Clock Repair (Eventually taught a portion of the class after becoming employee)

Awards and Honors
Small Business of the Quarter (Prattville, Alabama) Leadership Class of 2009 (Autauga County, Alabama)

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