[OP]
Contributor
I saw the design for this clock on a German clock maker's site and just had to build it.
I make my own plywood for clocks. That allows me to make any thickness needed in any species I want. This clock is made from maple and mahogany. I added a center ply of mahogany in the maple plywood and maple in some of the mahogany plywood, as you can see here.
To appreciate this clock, you have to watch it run.
https://photos.app.goo.gl/2DLRNLwdpYKpm5ed6
John
Contributor
What a beautiful piece! Well done, Sir! Well done, indeed!
Ken
So much to learn, so little time.....
Moderator
Beautiful and mesmerizing!
Please help support the Creek.
"The older we get, the fewer things seem worth waiting in line for."
Will Rogers
Contributor
John, absolutely fascinating. Well done, sir.
Best, Patrick
Contributor
That’s a nice piece of work, for sure!
"All that is necessary for the triumph of evil is that good men do nothing."
“If you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.”
Contributor
That is truly wonderful. Bravo!
Contributor
Wow!
That is wonderful in all the best senses of the word.
Are the brass? weights? in the pendulums to tune the periodicity?
Do you let it run on a regular basis?
smt
Contributor
Amazing work. Congratulations!
Mike
Go into the world and do well. But more importantly, go into the world and do good.
[OP]
Contributor
Thanks Stephen, and everyone else for the kind words. The original design has a 35 gm washer embedded in the ends of the fobs, covered by wood disks. I changed it to the brass inserts you see. I made them from 1" brass rod stock, cut to length, and then turned on my little lathe to remove metal on the back side until they all weighed 38 gms. It is the mass in the fobs that turn the escape wheel backwards when the mechanism that looks like a hook engages it, one on each pendulum. That little increase in stored energy is what keeps the clock running as it cycles. The weight of those fobs has to be within a pretty narrow range to have enough force to turn the escape wheel backwards but not so much that the hook won't release as the pendulum reaches the end of its period.
Yes, the weight in the top and bottom fobs can be adjusted to change the period of compound pendulum, analogous to changing the length of a standard pendulum. I ended up having to add 2 gms to both of the top fobs to get the clock to run within the drive weight range appropriate for the clock without stopping. Once you have the clock running in a stable manner, you adjust the drive weight to tune the timing. The brass tubes on the brass rods in the middle of the lower half of the pendulums can be used to adjust the timing, too. I used air rifle BB's in the plastic tube for the drive weight and just a few BB's + or - will give you the few seconds of accuracy. I'm still evaluating how accurate the clock will be, but grasshopper escapements are known for their accuracy, so I'm hoping for +/- a minute or two per week. I built a clock of my own design last year and it will run for at least 2 weeks without being more than a minute off.
I just finished this clock, but plan to let it run continuously, just like the others I've made. Another benefit of the grasshopper escapement is they are quiet. The sound is on in the video, and if you listen very carefully, aside from the floor creaking when I moved, you can just hear when those hooks are released, more so the left one. My wife hates the tick/tock of mechanical clocks. The grasshopper escapement meets her benchmark.
John
Posting Permissions
Reply With Quote