Making a wooden grasshopper clock according to John Harrison's principles
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- Опубликовано: 2 май 2023
- Making a wooden precision pendulum clock with grasshopper escapement according to John Harrison. The sculptural clock was self-built from multiplex, lignum vitae and beryllium bronze using mainly hand tools. Friction was reduced by self-lubricating bearings made from lignum vitae, by anti-friction wheels and by knife-edge bearings. The pendulum has adjustable temperature compensation pendulum, similar to Harrison's gridiron pendulum. The geometry of the gearing with a lantern pinion with rotating rollers and of the twin-pivot grasshopper escapement were optimized by calculating several variants. The electric remontoir, an automatic maintaining power windup mechanism, uses Christiaan Huygens' endless rope loop. The design of the clock, its assembly and setting it in motion is explained in detail. Available sources and literature and building materials I used are listed. A detailed documetaion of the design process and of the manufacturing of the clock can be found, although only in German, at www.uhrenwerkstattforum.de/t1...
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You sir are positively brilliant
Please try west Australian wandoo❤️
A hard wood with unique properties 🌿
Eine absolut genial konstruierte Uhr. Auf das Wesentliche bei der Konstruktion beschränkt. Gratuliere zu diesem Meisterwerk.
It is amazing to see this clock and it is beautifully made. I have made several wooden clocks with different escapements, as this is the bit I am most interested in. I made a grasshopper escapement clock about 25 years ago which is still running well. It does not have the low friction devices or temperature compensation you have but it does keep pretty good time. I used wooden gears with metal pin lantern pinions and the pivots are piano wire running in brass plate. I first made just the grasshopper escapement on a simple shaft which I adjusted until it ran well then made the final version for the clock.
Brilliant. Very inspiring.
That’s very cool, I’ve always wanted to be able to do that
Hermoso reloj!! Felicitaciones
The music blotted out the actual tick sound. Otherwise, very nice work.
Very impressive design and manufacturing process. Much to digest here. Which will require repeat watching of the video. I like the premise that oil, the bane of precision mechanical timekeeping is forbidden.
Three questions readily pop to mind. I am sure there will be more to follow.
1.What advantages do beryllium bronze pivots over a polished stainless steel pivot? Coefficient of friction? Obvious advantage over hardened and polished or burnished steel would be corrosion resistance in absence of oil.
2. Why not just use the glass mercury switch as the primary winding switch rather than the backup? I have never known a mercury switch to fail.
3. What motor and voltage is being used for the remontoire?
Thank you for producing and sharing the video of this well thought out expertly engineered and crafted "Harrison" type clock.
Thanks for your kind reply!
Ad 1: No specificic reason, apart from the fact that I simply wanted to avoid steel or iron metals, as Harrison did to avoid corrosion in salty sea air. He used simple brass pivots. Salty air is no problem for me, but I simply like beryllium bronze.
Ad 2: No specicfic reason either. Originally, I had in fact planned only a simple mercury switch operated by the weights. But triggering the windup every hour gives more time reserve in case of el. power outages, and a reed contact causes less reaction force on the minute wheel.
Would have loved to hwar the tick. Grasshopper escapement is reportedly quieter than most other escapements.
Great work! Are plans available for purchase anywhere?
Sorry, unfortunately not. My sketches and calculations are far from being self explanatory, I'm afraid, and most parts were traced directly on the wood before cutting the out, so the drawings are lost anyway.
Клас 😊❤
Cooles Video !! Bin gespannt, wie genau sie geht
Das würde mich auch interessieren.
After a little regulating, it stays well below an error of +/-1 second over a period of one million seconds (~12 days), being less than 1 ppm. Not to bad for a homemade clock from plywood.
@@p.hefetrueb2674 good job. Any chance you might release svg or cdr files so anybody can use a lasercutter to rebuild your watch?
@@raphi72 Unfortunately no way. As I said in the video, there are no CAD data. For most parts, there even are no paper drawings, as I traced them directly on the wood before cutting them out.
@@p.hefetrueb2674 clear photographs of each part separately from the same distance would probably be enough. It should be possible to extract paths from the bitmap as long as there is enough color difference to the background. Optimal with a ruler at the edge.
Wie heißt denn das Lied am Anfang des Videos?
"Tick Tock" von Jimmy Fontanez, lizenzfrei aus der Audio-Mediathek von youtube.
Out of interest. How accurate is your clock?
I'm still not finished with regulating, and might try another pendulum (real grid-itron pendulum), but so far it repeatably keeps the second over 12 days (less than 1ppm)
No thanks. I'll use my CNC router.
Lazy.
yeah but how would u get the fine teeth for the gears?