Just because two items are similar in function does not mean that their method of functioning is the same.
We wouldn't say that a quartz and mechanical keep time in an identical fashion simply because they show the time on a dial accompanied by at least two hands, right?

 

Oh, the effect of gravity on the 2 hands is another thing.

 

Being portable is clearly not the “main difference” between a balance and a pendulum. In the future I would recommend not using Hodonkey as a source for your research on any technical topic...

To be clear, the pendulum and balance comparison you are attempting to make fails in the very way you are trying to say they are “similar” so the semantic angle isn’t going to support your position here. If you take the time read and understand my posts it will be clear how this comparison doesn’t support your understanding.

If you are truly interested in learning how these things really work, you might want to abandon the quick straw man replies and do some actual study on the subject.

Cheers, Al

 

Motion of any object on earth is affected by gravity in one way or another. If you believe that the motion of the balance wheel is not affected by gravity apart from the effect of friction at the center that results from its weight, then I can't do anything about that.

 

I'd take Hodinkee and many other sources over a single person's opinion.

https://www.quora.com/I-understand-...of-gravity-on-the-movement-How-does-this-work

But your finger (or the mainspring) isn't the only thing exerting force on this little system. Gravity is too. Let's say the balance wheel is in a vertical position, like a clock on a wall. If you rotate the balance wheel around in that position, the amount of swing (or amplitude) will change based on its angular position. Think of it this way- image you orient the balance such that the spring is totally relaxed- it's hanging down at 6 o'clock of the watch face. Now rotate everything a quarter turn in either direction. The amplitude will be a little more in the downward direction, and a little less in the upward direction due to gravity. This affects the period of the swing, and thus the timing of a watch. The timing will change ever so slightly when you hold your wrist down at your side versus flat on a table.

 

It's a drag this discussion seems to be resulting in so much friction. There is much for the OF masses to get from this thread, and I am sure there are others who may weigh in with even more info. Discussions like this can accelerate one's understanding of mechanical watches. I only hope the gravity of situation does not lead me to a movement.

 

You have a particular talent for blatantly misstating what I have said in order to argue your points. I’ll remind you what I said in my first post on this subject on the previous page:

“As far how gravity affects the balance, and how that affects timekeeping is a lot more complex than you are indicating”

I’ve never said that the balance is not affected by gravity, and in fact I’ve repeatedly said otherwise.

“When there is a serious poise error in the balance, this leads to a timing error that will show in only the vertical positions - this is one way where gravity can affect the timing that is not related to friction“

So either you really don’t understand this at all, or you are purposely misrepresenting what I’m saying to save face. In either case it doesn’t appear that you have an interest in having a genuine discussion.

Cheers, Al

 

I don't know how much gain or loss my Railmaster is having in this position. But who cares? After more than a year of ownership, I am still in love with it. No more, no less.

 

Pendulums and balance wheels are both harmonic oscillators, but thats kind of where the similarities end. For a pendulum, the restoring force is gravity, whereas for the balance wheel, the spring force is the restoring force. @Theognosis Hodinkee definitely has it pretty wrong on this one, since the major difference is clearly not portability, as Archer said – one literally relies on gravity to function, while gravity is a hindrance to the other.

 

No argument here. The point is gravity affects the motion of the pendulum and the balance wheel. The subject of portability is irrelevant.

 

This post some time back perhaps would’ve saved our some precious time reading posts that were quite technical to us but we read just to know what was being discussed there. Thank you dear.

 

I think you're totally missing the point. Gravity affects literally everything on Earth, in space, et cetera. That's a given. The point is that gravity is a necessary condition for the operation of a pendulum clock, but not a necessary condition for the operation of a mechanical watch. You're treating gravity as a detrimental factor in the operation of both, which is the reason Archer is pulling his hair out.

 

Actually, gravity becomes a detrimental factor (among many things) in the pendulum's upswing motion--and that's why it eventually stops.

 

No... it doesn't. If gravity suddenly vanished during the upswing, the pendulum would not return to center, and the clock would cease to function. You really have no clue what you're talking about.

 

If gravity stops during the upswing, the ball of the pendulum will continue on its upward trajectory and go full circle (due to inertia). You don't know what you're talking about.

 

A pendulum stops because of air resistance and friction at the point of rotation. If we lived in an ideal, frictionless world, pendulums would run forever. You need to do basic research before saying these kinds of things.

 

No. On the upswing, the force of gravity is pointed downwards, thus resisting the motion of the ball. When the ball stops, gravity will push it downward again. Do your research please.

 

https://www.youtube.com/playlist?list=PL8dPuuaLjXtN0ge7yDk_UA0ldZJdhwkoV

Anyone down for learning some mechanics?

 

I'm actually getting a good laugh out of this. You don't understand how pendulums work. The bob oscillates in arc because gravity acts as a restoring force. The bob cannot rotate in a full circle because thats not how the mechanism of a pendulum clock functions.

Everyone knows gravity pulls the ball downwards, that's literally why it keeps swinging back and forth. What eventually stops it is friction from air resistance and at the point of rotation. The energy of the ball is lost through friction and becomes heat, until the pendulum stops. Gravity does not stop the pendulum, because gravity is what moves the pendulum.