Bepi, The clock that I had was a Russian "Etalon", a copy of the Shortt free pendulum clock. I rated the free pendulum at atmospheric pressure with a weight on the rating tray which, by trial and erro

Until recently, I ran a clock under reduced pressure. The aim was to operate at a constant tank pressure, below the lowest ambient atmospheric pressure so I chose 600mm Hg. The tank was exhausted with

Derek et al, If you look at my design, the upper pivot of the gravity arms have an extended arm which can be rotated to add to or detract from the force applied by the gravity arms. As these arms are

I know I'm going to regret this, but surely mass itself has no direct bearing on period. The heavier the bob, the lower the c of g (or more correctly the centre of mass) which has the same effect as l

Hi Derek, Thanks for your input. As you said, an interesting discussion has started which is always good. Turning to the question of using heavier gravity arms, that is directly the opposite of what I

Hi Darren, Thanks for your comments. I have some railway relays with carbon/silver contacts and it never occurred to me to adopt that combination. In my clock, the easiest way to do this would be to f

John, Both actually! I first submitted it to the BHI, with a very muted level of enthusiasm on their part and I eventually withdrew it. The next port of call was teh AHS Electrical Group to be sent ou

Hi All, With all this stuff about re-inventing the Synchronome, I thought it would be a good time to introduce another new electric clock concept - at least parts of it are a new concept. The clock in

This is an example of exactly what I feared would happen. As a non-facebook user, I (and others like me) are now barred from sharing information which would otherwise be available to all. Large files

John, I admire what you're doing, but for me the main appeal of a genuine Synchronome is aesthetic - it's a beautiful piece of kit which looks like a real scientific instrument. Its timekeeping is cap

Hi Bepi, You're being inundated with good advice from the knowledgeable folk on this group - and here's another bit!! Having now watched your YouTube video, I notice that the gathering click is just n

Hi Bepi, Further to what John wrote, you should bear in mind that the pulling round of the count wheel is the major drain of energy from the pendulum (only to be replaced every 30 seconds by the gravi

It's yer penumbra! Ian R Macclesfield

I find that very hard to believe from my practical experience. I recently had a clock in which I replaced the suspension spring and it refused to run for any length of time, and the arc was restricted

Chatterton's Compound was, I believe, the stuff used to stick the dial on!! I think it may be soluble in acetone or similar and shouldn't damage the dial. Good luck, Ian R Macclesfield, UK

All very interesting, but what has it to do with Synchronome? It only goes to show how clever - and simple - F H-J's concept was, and still is today. Just my opinion of course Ian R Macclesfield, UK

John, In the original Synchronome, there is a brass bush fitted into the hole in the bottom of the bob, with a hole for the rating screw to pass through. Thus the rating nut is bearing on the brass bu

Graham, A guess, but from the presence of the drive magnets at the bottom of the case, it is probable that this clock has (or had) a Hipp toggle switch - along the same lines as the Magneta shown on y

Neil, How many of your 17 tell the right time? As someone once said, "he who has a clock always knows the time; he who has two is never sure!" Ian R Macclesfield, UK

John et al, Thanks for posting that, someone else already did a wee while ago with some additional annotation. I also have a copy of that book and have always thought it curious to note that amongst t