Introduction: Jefferson-Inspired Daily Clock: Quarantine Edition

About: Currently a professional Papa. Maker/educator/lecturer/cicerone/laserist. I'm doing my best!

At the time of publishing, I have been stuck in COVID-19 related quarantine for thirty-three days. I am beginning to come unglued from normal time—each day seems very like the last, with little to make an impact on my memory. In short, I cannot ever seem to recall what day it is.

Frequently I turn to history to solve my problems, and as it happens, the answer was very close to my heart. In a previous period of my life, I had occasion to spend many hours at Monticello, sometimes in long enough stretches to also lose track of the day of the week. As luck would have it, Thomas Jefferson had a solution to this problem!

In the Entrance Hall at Monticello, there is a Great Clock. It is a weight driven clock—once a week (Sunday morning) a set of weights is wound to the top of the wall, and as the week goes along, the gravitational potential energy of the weights is converted to the kinetic energy to advance the clock, and the weights slowly sink down. Jefferson eventually had markers added to the wall, one for each day, so that by looking at the position of the weights you could tell what day it was. (Interestingly, the full run of the weights was greater than the height of the room the clock was in, so holes were cut in the floor, and the weights spend most of Friday and all of Saturday in the basement, complete with a matching marker.)

It's something I'd often pondered replicating at home! I'd come up with many ideas for how to do it—arduinos and servo motors and neat coding and the like—but I have none of those supplies to hand at the moment. I set myself the challenge of making something using only the supplies I had on hand and those I could pick up in my weekly essential-grocery run. This is what I came up with!

NB: While a historical discussion is outside of the purview of this Instructable, I'd feel derelict in my duty if I didn't very briefly mention: Thomas Jefferson was a complicated person. He did some very good things. He did some very bad things. It's worth looking into!


Keep in mind—this is stuff I pieced together that I had access to. There is a lot of room for being creative here, substitute at will!

Definitely needed:

  • Quartz Clock Movement or clock which you can harvest a movement from—I used one of these, which has the advantage of being cheaper than buying a bare clock movement. (Cut out an image to fit in the discarded case, and you have a kinda-cute picture frame for no extra work!)
  • A spool of some kind—I ended up using a spare bobbin.
  • String or thread
  • A (light) weight—could be some paperclips or a fishing weight; I used some pony beads.
  • A writing utensil of some kind.

Makes it look nicer if you have:

  • Craft Sticks
  • Paint/Markers/Things to add color to things—I used some 50¢ black paint, a gold metallic paint pen, and some sharpies.
  • Glue of some kind—I used hot glue.
  • Something to affix signs to a wall-I happened to use fun-tack, small nails or tape or glue would have worked too.
  • Scissors or a saw

Only necessary for the funny part:

  • A drill and some bits

Step 1: The Clock

Fundamentally, what we want to do is to lower a string a set amount per day. There are many ways to do this- possibly the easiest is if you already have a weight driven clock—but I chose to scavenge a quartz clock movement. The hour hand in an ordinary clock rotates one full turn every twelve hours, and thus two turns a day. The idea is to attach a wheel to that movement.

Figure out about how much distance you want between each day marker (this will depend a lot on the kind of marker you end up with; if you make signs the way I did, 10cm seemed about right). Multiply this by seven to give you the total length of your clock (in my case, 70cm). Find someplace where you can hang this, and make sure that length of thing will look okay in that space, if not, adjust as needed. Once you've settled on the distance between two day makers, the fun (ok, the math) begins!

We know the hour movement on the clock rotates twice per day. We know the distance our string needs to travel in that time (in my case, roughly 10cm). Now we need to find out the size of wheel we need to make that work: we need two full circumferences of the circle to equal one day's movement. The circumference of a circle is equal to it's diameter multiplied by π. Since we need two of those, our diameter is going to equal one day's distance divided by 2π (in my case, 1.59cm). Now: hunt for a wheel!

I looked at medicine bottles, washers, coins, styrofoam balls, bits of scrap plastic, I even contemplated cutting what I needed out of cardboard. Bear in mind, you don't have to find something exact, just close. You also should strive for something light—clock movements are designed to move hands, not wheels, and you don't want to over-stress the mechanism. When you find something you like, multiply its diameter by 2π and see if it'll work for you! I eventually settled on a mostly-wound spare bobbin, with a diameter of 1.81cm, which gave me a day length of 11.36cm and that looked just fine.

Whatever you come up with, secure some thread or string to it, and wrap it around with enough string to go around at least 14 times plus the distance you want the mechanism away from the first marker. Happily, the bobbin already had more than enough thread to work.

Lastly, you need to secure the wheel to the hour part of the movement. You could drill a precisely-sized hole to grip onto the right portion of the movement—but why do that when someone already has gone to that trouble for you? Just trim the hour hand down to fit your wheel, and glue it on. You'll need some kind of hole behind it, the hour part of the mechanism is the lowest down and you need somewhere for the minute and second part to sit, but this doesn't need to be a precise hole in the least, just bigger than the hole in the hour hand and small enough that the hour hand will still glue securely to the outside of the wheel. Snap the wheel on, check that the movement still moves (use the setting function to sweep the hands around), and the hard part is done!

Step 2: The Weight

A bare sting on its own will not hang properly, so you need something to weight it down with. The goal here is to get something as light as possible (avoid stress on the mechanism) while still keeping the string vertical. Almost anything will do—paper clips, fishing weights, washers—Jefferson's clock used cannonball-shaped weights, and as I wanted to mimic that, I settled on some pony beads. I hot-glued six of them to a cotton swab, and then painted them black. Whatever you end up with, tie it on the end of the string.

If you are feeling barebones at this point, skip ahead to the part where we hang it; what follows is largely increasing efforts on my part to make something that reminded me of Monticello.

Step 3: The Day Markers

One can totally just write the days of the week on the wall with appropriate spacing; but I wanted to echo Monticello's clock. The markers there are rather elegantly hand-painted plaques; I contemplated printing out photos of those markers and laminating them, but it seemed more fun to paint them myself.

First, I painted a set of craft sticks flat black. Two coats did a nice job! (Bonus secret instructable: Did you leave all your paintbrushes in your last house like me? Did you forget you'd need some when you got your last batch of quarantine-essential groceries? A cut piece of a sponge superglued to a popsicle stick made an inadequate but ultimately-usable brush!)

I then used a gold paint pen to handwrite the days of the week, copying as best as I could from photos of the originals, and accepting all the happy accidents as more proof it was made by hand. I cut the sticks down to size (I elected not to do this first so that I could center the words on the final marker by adjusting the cuts—I had no confidence in my skill at evenly spacing letters, and as you can see from the photos, I was correct not to have any!), went over the ends with a black permanent marker, and was ready to continue.

Step 4: Hang It!

Right! Hang the movement on the place you want it to be. Drop the weights to the bottom of their range, and measure upwards from there with a ruler, marking out each day. Then, label the days however you like, be that with signs like in the previous step, stickers, thumbtacks, or sharpie on the walls. I can recommend poster tack if you've made signs, it makes it very easy to readjust things if you find out your math/measuring skills were not quite up to snuff. Adjust the clock mechanism so the weight is lined up with the current day, and you are done!

One note: When the week is over, you will need to wind the string back up to the top. I find it easiest to just take the mechanism off the wall and wind it, but feel free to be creative. TJ had a ratcheting key to help wind up the weights. It takes some time, sure, but it gives you a minute to reflect on the week that has passed, plan for the week to come, and also notice that a week has gone by in the first place if you are deep into social isolation like me.

The next step is frustrating and not needed, but I was bored, I wanted to impress some old friends, and the project would not have felt complete to me without it.

Step 5: Bonus Step: Friday, and the Hole in the Floor.

As I mentioned earlier, the weights of the clock at Monticello go through a hole in the floor. It is oddly the one fact that nearly everyone remembers if they visit, and a popular thing to point out on tours. It's also cute, and I like it.

I took a few craft sticks, and hot glued together a 'floor' section. The floor at Monticello is a beautiful grass green; I only had a green sharpie, but I did my best to color it in, and to 'stain' the underside (with a brown sharpie, of course).

Monticello's weights do not hang directly under the clock because the front door is there, they go to the side wall and then drop down; I fashioned a pulley from a spare bobbin and a paperclip and mounted it accordingly. I then temporarily hung my 'floor', dropped the weights until they hit it, marked where they hit, and drilled an appropriately sized hole in that location. It lines up right about every sixth time, but it's not a big trouble to tap it in Friday morning, and when it does work right it's a lovely confidence boost.

I happened to have an old miniature replica of the Great Clock to mount in the appropriate location; it has never worked for more than a few days at a time but that is actually pretty historically accurate, the real clock was built in, as TJ put it, a "bungling manner" and has broken down regularly for 227 years.

Hang in there, everyone; this too will pass. Be safe, be well, and thank you for reading this!

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