Wierd Pendulum Period
Bill Bowden
that has a pendulum period of about 53 beats per minute.
It's some non-exact value I haven't determined yet. Is there some
reason for this weird timing, rather than making the period exactly 1
second? Why would it be designed this way?
-Bill
dAz
hehe! welcome to the wonderful world of wacky clock trains, unlike
watches clock makers have no need to stick to standard beat counts, to
whatever size pendulum fits in the case the train count is adjusted to suit.
generally a pendulum of just under a metre is a seconds beat, 3600bph or
60 beats per minute, grandfather, long case and regulators mostly have
pendulums of this length, however not always the case, these newer
grandfathers with the very ugly wide lyre pendulums can be longer than a
metre, in fact Hermle lists 3 different lengths for their grandfather
movements all of which are longer than a metre so they actually beat a
bit longer than a second, these clocks do have a seconds hand which is
geared separate to the escape wheel instead of being mounted on the
extended escape wheel pivot as was the norm for older longcase clocks,
the gearing is adjusted to suit the train count for the longer pendulum
so the seconds hand goes around at the correct speed.
looking through my clock trains list I see most of the 31day korean
clocks are short pendulums, if yours is beating 53bpm or 3180bph then
the pendulum is 1273mm long.
you count the beats as one swing from one side to the other, a single
'tick' not as eg; from left to right then back to the left again, that
is 2 beats.
so at a guess your clock is beating 106bpm and the only trains I have
listed close to that is 102.14bpm(6128.57bph) and
102.0625bpm(6123.75bph) these have pendulums around 345mm long which is
the norm in most 31day wall clocks
Invalid
<6a8b78d9-ede5-4cd1...@d21g2000prf.googlegroups.com>,
Bill Bowden <wronga...@att.net> writes
The design wheel count gets you to the BPH figure, without a seconds
hand it really doesn't matter what the beats per second figure is.
Many 4800bph Vienna regulators have a subsidiary "seconds" hand that
goes round in 45 seconds, and I have a 3400bph year going Vienna where
the seconds hand goes round in just over 63.5 seconds.
--
Peter R Cook
dAz
> Just a guess 3200 Beats per hour 53.33333333 beats per minute?
>
> The design wheel count gets you to the BPH figure, without a seconds
> hand it really doesn't matter what the beats per second figure is.
>
> Many 4800bph Vienna regulators have a subsidiary "seconds" hand that
> goes round in 45 seconds, and I have a 3400bph year going Vienna where
> the seconds hand goes round in just over 63.5 seconds.
>
>
not as simple as that, one of the most common GB vienna trains I have
seen are 4860bph so the seconds hand goes around in 44.4seconds and of
course the seconds dial is marked with 60 strokes, would have been
simpler if the seconds did go around in 45seconds and the seconds dial
marked as so.
a lot of clocks have fractional train counts, a french carriage clock I
did a couple of months back did 17678.57bph with a conventional lever
platform, the contrate wheel was 55teeth, had it had 56teeth the train
would have been a normal 18,000bph, but no, it was a custom job which of
course made it a pain to time, the b200 didn't want to know, a far it
was concerned the clock was losing 25min and 42seconds a day :) which
was beyond the timing scale, fortunately the microset had no problem.
The Baron
"Bill Bowden" <wronga...@att.net> wrote in message
news:6a8b78d9-ede5-4cd1...@d21g2000prf.googlegroups.com...
Jack Denver
length (and therefor the period) of the pendulum to the gear ratio of the
train. Since it is always possible to adjust the gear ratios appropriately,
there is no compelling need to have a 1 second pendulum though it makes
having a second hand easier, if you have one at all.
"Bill Bowden" <wronga...@att.net> wrote in message
news:6a8b78d9-ede5-4cd1...@d21g2000prf.googlegroups.com...
Bill Bowden
Yes, it's running 107 now. At 106, it was about 4 seconds slow in 14
hours, so I speeded it up a little to 107 to bring it closer. I'll
find out the error in a day or so and make more adjustments. I have a
little weight mounted on the pendulum to adjust speed.
-Bill
Bill Bowden
>
> - Show quoted text -
opps, that should have been 4 minutes slow, not seconds.
-Bill