Off topic question (clock repair)

[klem kedidelhopper]

Sorry to post this question here but I really didn't know where else
to address it to. It is obviously not electronics related however I
was hoping that someone could never the less help me.

I was given this really nice wall clock. The clock was missing the
pendulum and the winding key when I received it. The clock is supposed
to chime once on every half hour and then appropriately the correct
number on every hour.

A friend who does clock repair gave me a small pendulum and a key. He
said the size of the pendulum is not too critical and so he thought
that the one he gave me should work. Well it does however the clock is
really running slow. It sounds like it's in perfect beat though, and
although I've run the pendulum up the stick pretty high now it's still
a few minutes slow over a two hour period. I've tried adding some
weight to the pendulum but that didn't seem to make any difference.

The clock doesn't look gummy but it is dry. I had planned to spray the
movement down with a no residue cleaner and then oil every thing that
moves with a light oil. I just didn't want to possibly introduce
another problem into the equation before I fix the current one.

So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical? My friend says
no, however the loss of several minutes over the course of two hours
seems really excessive. Is it possible that the incorrect pendulum is
causing the current problem and that perhaps there might not even be a
problem if I had the correct pendulum? Could the need for a cleaning
and lubrication cause such a speed error?

The movement seems to be a fairly nice one and primarily is of brass.
Above the manufacturers name, (Mason and Sullivan Co.) there is a
number 75. Below that it reads: "no (0) jewels" next line: "Made in
West Germany" Below that: " unadjusted" and below that : "141-070".
Then on the bottom line there is the following:

29cm
----------
130.37

If anyone has some advice for me as to my questions and how to proceed
with this project I would be very grateful. Thanks for any advice on
this. Lenny

 

[isw]

In article
<17fdbc2c-7285-4cf7-b350-c07c7fa54dfe@o30g2000vbu.googlegroups.com>,
klem kedidelhopper <captainvideo462009@gmail.com> wrote:

Sorry to post this question here but I really didn't know where else
to address it to. It is obviously not electronics related however I
was hoping that someone could never the less help me.

I was given this really nice wall clock. The clock was missing the
pendulum and the winding key when I received it. The clock is supposed
to chime once on every half hour and then appropriately the correct
number on every hour.

A friend who does clock repair gave me a small pendulum and a key. He
said the size of the pendulum is not too critical and so he thought
that the one he gave me should work. Well it does however the clock is
really running slow. It sounds like it's in perfect beat though, and
although I've run the pendulum up the stick pretty high now it's still
a few minutes slow over a two hour period. I've tried adding some
weight to the pendulum but that didn't seem to make any difference.

The clock doesn't look gummy but it is dry. I had planned to spray the
movement down with a no residue cleaner and then oil every thing that
moves with a light oil. I just didn't want to possibly introduce
another problem into the equation before I fix the current one.

So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical?

Weight, no; length, yes. The length alone determines the period of the
pendulum. The weight just needs to be heavy enough to not be affected by
air resistance, and light enough to not damage the bearings that support
it.

My friend says
no, however the loss of several minutes over the course of two hours
seems really excessive. Is it possible that the incorrect pendulum is
causing the current problem and that perhaps there might not even be a
problem if I had the correct pendulum?

Yes.

Could the need for a cleaning
and lubrication cause such a speed error?

I suspect that the major result of crud in the works would be a tendency
for the pendulum to stop, or for timekeeping to be erratic.

If anyone has some advice for me as to my questions and how to proceed
with this project I would be very grateful. Thanks for any advice on
this.

What did you mean by "sounds like it is in perfect beat"?

Isaac

 

[klem kedidelhopper]

On Nov 24, 2:00 am, isw <i...@witzend.com> wrote:

In article
17fdbc2c-7285-4cf7-b350-c07c7fa54...@o30g2000vbu.googlegroups.com>,
 klem kedidelhopper <captainvideo462...@gmail.com> wrote:









Sorry to post this question here but I really didn't know where else
to address it to. It is obviously not electronics related however I
was hoping that someone could never the less help me.

I was given this really nice wall clock. The clock was missing the
pendulum and the winding key when I received it. The clock is supposed
to chime once on every half hour and then appropriately the correct
number on every hour.

A friend who does clock repair gave me a small pendulum and a key. He
said the size of the pendulum is not too critical and so he thought
that the one he gave me should work. Well it does however the clock is
really running slow. It sounds like it's in perfect beat though, and
although I've run the pendulum up the stick pretty high now it's still
a few minutes slow over a two hour period. I've tried adding some
weight to the pendulum but that didn't seem to make any difference.

The clock doesn't look gummy but it is dry. I had planned to spray the
movement down with a no residue cleaner and then oil every thing that
moves with a light oil. I just didn't want to possibly introduce
another problem into the equation before I fix the current one.

So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical?

Weight, no; length, yes. The length alone determines the period of the
pendulum. The weight just needs to be heavy enough to not be affected by
air resistance, and light enough to not damage the bearings that support
it.

My friend says
no, however the loss of several minutes over the course of two hours
seems really excessive. Is it possible that the incorrect pendulum is
causing the current problem and that perhaps there might not even be a
problem if I had the correct pendulum?

Yes.

Could the need for a cleaning
and lubrication cause such a speed error?

I suspect that the major result of crud in the works would be a tendency
for the pendulum to stop, or for timekeeping to be erratic.

If anyone has some advice for me as to my questions and how to proceed
with this project I would be very grateful. Thanks for any advice on
this.

What did you mean by "sounds like it is in perfect beat"?

Isaac

I meant that it produces an even "Tick, Tock", as opposed to a "Tic
Tic, Tock", or "Tic, Tock Tock" sound. Lenny

 

[Michael A. Terrell]

klem kedidelhopper wrote:

Sorry to post this question here but I really didn't know where else
to address it to. It is obviously not electronics related however I
was hoping that someone could never the less help me.

news:alt.horology is the newsgroup for clocks & watches. You should
be able to get help here.

 

[hr(bob) hofmann@att.net]

On Nov 24, 8:37 am, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

klem kedidelhopper wrote:

Sorry to post this question here but I really didn't know where else
to address it to. It is obviously not electronics related however I
was hoping that someone could never the less help me.

   news:alt.horology is the newsgroup for clocks & watches. You should
be able to get help here.

Finally a worthwhile suggestion/comment.

 

[tuinkabouter]

On 11/24/2012 6:24 AM, klem kedidelhopper wrote:

Sorry to post this question here but I really didn't know where else
to address it to. It is obviously not electronics related however I
was hoping that someone could never the less help me.

I was given this really nice wall clock. The clock was missing the
pendulum and the winding key when I received it. The clock is supposed
to chime once on every half hour and then appropriately the correct
number on every hour.

A friend who does clock repair gave me a small pendulum and a key. He
said the size of the pendulum is not too critical and so he thought
that the one he gave me should work. Well it does however the clock is
really running slow. It sounds like it's in perfect beat though, and
although I've run the pendulum up the stick pretty high now it's still
a few minutes slow over a two hour period. I've tried adding some
weight to the pendulum but that didn't seem to make any difference.

The clock doesn't look gummy but it is dry. I had planned to spray the
movement down with a no residue cleaner and then oil every thing that
moves with a light oil. I just didn't want to possibly introduce
another problem into the equation before I fix the current one.

So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical? My friend says
no, however the loss of several minutes over the course of two hours
seems really excessive. Is it possible that the incorrect pendulum is
causing the current problem and that perhaps there might not even be a
problem if I had the correct pendulum? Could the need for a cleaning
and lubrication cause such a speed error?

The movement seems to be a fairly nice one and primarily is of brass.
Above the manufacturers name, (Mason and Sullivan Co.) there is a
number 75. Below that it reads: "no (0) jewels" next line: "Made in
West Germany" Below that: " unadjusted" and below that : "141-070".
Then on the bottom line there is the following:

29cm
----------
130.37

If anyone has some advice for me as to my questions and how to proceed
with this project I would be very grateful. Thanks for any advice on
this. Lenny

The length of the pendulum should be reduced. Usual there is a nut at
the underside of the pendulum. Turn the nut to get the weight closer to
the clock. T = 2 Pi sqrt(L / g)
where L is the length of the pendulum and g is the local acceleration of
gravity. It is independent of the mass.

See https://en.wikipedia.org/wiki/Pendulum

 

[josephkk]

On Fri, 23 Nov 2012 21:24:36 -0800 (PST), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

The movement seems to be a fairly nice one and primarily is of brass.
Above the manufacturers name, (Mason and Sullivan Co.) there is a
number 75. Below that it reads: "no (0) jewels" next line: "Made in
West Germany" Below that: " unadjusted" and below that : "141-070".
Then on the bottom line there is the following:

29cm
----------
130.37

If anyone has some advice for me as to my questions and how to proceed
with this project I would be very grateful. Thanks for any advice on
this. Lenny

The bottom number is the length and mass of a proper pendulum. Use a
search engine to find one.

?-)

 

[josephkk]

On Fri, 23 Nov 2012 23:00:28 -0800, isw <isw@witzend.com> wrote:

So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical?

Weight, no; length, yes. The length alone determines the period of the
pendulum. The weight just needs to be heavy enough to not be affected by
air resistance, and light enough to not damage the bearings that support
it.

Can't be. Almost every pendulum clock (not controlled by line frequency
or a crystal) is adjustable by moving the weight along the length of the
pendulum. Thus it must be the moment arm instead of the pure length.
Check the units of the equations.

?-)

 

On Mon, 26 Nov 2012 00:08:43 -0800, josephkk
<joseph_barrett@sbcglobal.net> wrote:

On Fri, 23 Nov 2012 23:00:28 -0800, isw <isw@witzend.com> wrote:


So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical?

Weight, no; length, yes. The length alone determines the period of the
pendulum. The weight just needs to be heavy enough to not be affected by
air resistance, and light enough to not damage the bearings that support
it.

Can't be. Almost every pendulum clock (not controlled by line frequency
or a crystal) is adjustable by moving the weight along the length of the
pendulum. Thus it must be the moment arm instead of the pure length.
Check the units of the equations.

?-)

Terminology is interfering with communication. There are two
'lengths' of a pendulum. The obvious one is the physical length. The
important one for timekeeping is the effective length (or as you
describe it, the moment arm). This is the distance from the pivot
point of the pendulum hook to the center of mass of the pendulum.

PlainBill

 

[Jon Elson]

klem kedidelhopper wrote:

A friend who does clock repair gave me a small pendulum and a key. He
said the size of the pendulum is not too critical and so he thought
that the one he gave me should work. Well it does however the clock is
really running slow. It sounds like it's in perfect beat though, and
although I've run the pendulum up the stick pretty high now it's still
a few minutes slow over a two hour period. I've tried adding some
weight to the pendulum but that didn't seem to make any difference.

weight makes no difference, strictly. Only the distance between

the center of gravity and the pivot point controls the timing.

Then on the bottom line there is the following:

29cm
Hmm, that could be the correct pendulum length, maybe?

29 cm = 11.42"

There are second-order effects, though. Too light a pendulum allows
the escapement to dominate the swing. But, if adding the weight high
on the pendulum doesn't help, then that isn't it. (Adding the weight
low on the pendulum effectively lowers the CG, making the pendulum
swing slower.)

Jon

 

[josephkk]

On Mon, 26 Nov 2012 10:05:49 -0700, PlainBill@yawhoo.com wrote:

On Mon, 26 Nov 2012 00:08:43 -0800, josephkk
joseph_barrett@sbcglobal.net> wrote:

On Fri, 23 Nov 2012 23:00:28 -0800, isw <isw@witzend.com> wrote:


So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical?

Weight, no; length, yes. The length alone determines the period of the
pendulum. The weight just needs to be heavy enough to not be affected by
air resistance, and light enough to not damage the bearings that support
it.

Can't be. Almost every pendulum clock (not controlled by line frequency
or a crystal) is adjustable by moving the weight along the length of the
pendulum. Thus it must be the moment arm instead of the pure length.
Check the units of the equations.

?-)

Terminology is interfering with communication. There are two
'lengths' of a pendulum. The obvious one is the physical length. The
important one for timekeeping is the effective length (or as you
describe it, the moment arm). This is the distance from the pivot
point of the pendulum hook to the center of mass of the pendulum.

PlainBill

Thanks. I knew that something wasn't getting across.

?-)

 

[klem kedidelhopper]

On Nov 27, 7:05 pm, josephkk <joseph_barr...@sbcglobal.net> wrote:

On Mon, 26 Nov 2012 10:05:49 -0700, PlainB...@yawhoo.com wrote:
On Mon, 26 Nov 2012 00:08:43 -0800, josephkk
joseph_barr...@sbcglobal.net> wrote:

On Fri, 23 Nov 2012 23:00:28 -0800, isw <i...@witzend.com> wrote:

So I had some questions. i don't know what this pendulum that he gave
me is from. Is the pendulum weight and length critical?

Weight, no; length, yes. The length alone determines the period of the
pendulum. The weight just needs to be heavy enough to not be affected by
air resistance, and light enough to not damage the bearings that support
it.

Can't be.  Almost every pendulum clock (not controlled by line frequency
or a crystal) is adjustable by moving the weight along the length of the
pendulum.  Thus it must be the moment arm instead of the pure length.
Check the units of the equations.

?-)

Terminology is interfering with communication.  There are two
'lengths' of a pendulum.  The obvious one is the physical length.  The
important one for timekeeping is the effective length (or as you
describe it, the moment arm).  This is the distance from the pivot
point of the pendulum hook to the center of mass of the pendulum.

PlainBill

Thanks.  I knew that something wasn't getting across.

?-)

Thanks for all the great advice guys. I cleaned and lubricated the
bushings, it now runs great and I am slowly creeping up on the
correct pendulum position. Lenny