A Clock Story to Help Pass the Time (Making a Clock Run Longer; The Jefferson Story)

Waiting for his clock plans to arrive via USPS Mail to Italy (mail to Italy is notoriously and agonizingly slow--can't be helped, sorry), Marco emails:
"Hello Clayton,

Thank you for the list of materials needed to realize the clock. I didn't receive anything yet. Every time I see the postman, I run after him asking if there is something for me, and he always answers "nothing".
Waiting is so exasperating.  Meanwhile I tried to assemble a clockwork, I almost succeeded but I have to wind it up every 8 hours (4.9 foot string and 6 lbs weigh). If you don't mind my asking , I would like to know if there is a method to improve the charge (at least 24h...).

Thank you for being so patient, I'm so happy to talk to such an expert as you are!

Bye, Marco

P.S. Maybe we'll meet one day (even if we live so long way away...) "

Clayton answers,

"Aloha Marco, I completely understand your feeling of anxiousness. I remember the first set of plans I sent away for. The wait was agonizing! Hopefully your postman will greet you with your package very soon. Thank you for your patience.

There are a few ways to make a clock run longer. The most obvious is to hang the clock higher on the wall. That may sound facetious but it is exactly what Thomas Jefferson (U.S. third president) did in his own dining room at his home in Monticello.

Jefferson designed a clock that would run a week on a wind and hung it at the ceiling of his dining room. He then ran the weights down the corners of the room where he had painted on the wall the day of the week. He would wind on Sunday so Sunday was shown in the top corner of the wall. As the weight dropped during the week, it would align with the day of the week painted on the wall.

Unfortunately, Jefferson calculated his radians incorrectly and the clock only ran six days before the weight hit the floor. To solve this problem Jefferson cut a hole in the floor of his dining room and that allowed Saturday to be down in the cellar. (Knowing that the genius of Jefferson occasionally messed up always makes me feel a bit better whenever I screw up a design)

Another way of adding run time is to add another gear at the bottom of the clock's train, but that would require redesigning your clock.

The easiest way in your case is to add a pulley. A single pulley will double the run time - but you must also double the drive weight. Still that would only give you 16 hours run time.

Because your clock only runs for 8 hours and you want to wind it only once a day, your clock would require a combination of pulleys to at least treble the run time. Or you could use a combination, such as hanging the clock higher on the wall and using a doubling pulley.

Rewinding a clock mounted high up on a wall is a bit more difficult - Jefferson brought in a ladder each Sunday to wind his clock. I am presently working on a new clock design with a Huygens Endless Chain rewind system that should simplify rewinding a lot.

For most of my clock designs I recommend stopping the pendulum when rewinding the clock because the force going through the system changes during rewinding and that can affect how the pallets and escape wheel interact. With a Huygens Endless Chain system there should be no need to stop the pendulum when rewinding because the force through the system should remain fairly constant. The big plus is that rewinding time should be decreased dramatically for each clock with the Huygens system.

Please send me pictures of your clock experiment.


Aloha. Clayton"

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I love comments, but in order for me to have more time playing in my sawdust, I cannot respond to them here. If you have a technical question, please do not post it here, or I will have my wife answer it for me and her technical knowledge is highly suspect. For technical questions, check out the FAQ section of my website, or find my email link there. Mahalo and Aloha, Clayton