I have an old (Victorian) pendulum spring wall clock. I finally got it to
keep good(ish) time by adjusting the pendulum length.
Recently it has taking to losing 11 minutes then it continues merrily on
its way not losing any more. It's always ~11 minutes (ie not 8 or 13). If I
reset it, it will sooner or later do the same thing.
Any ideas?
--
Jim on Tyneside UK
Remove X to email me.
http://freespace.virgin.net/mr.jimscott/

Jim Scott wrote:
I have an old (Victorian) pendulum spring wall clock. I finally got it to
keep good(ish) time by adjusting the pendulum length.
Recently it has taking to losing 11 minutes then it continues merrily on
its way not losing any more. It's always ~11 minutes (ie not 8 or 13). If I
reset it, it will sooner or later do the same thing.
Any ideas?

Pendulum length is set correctly once only in the life of the clock. If
it then drifts I would suspect friction due to muck in the mechanism,
rust, things like that. It is better to clean rather than just oil,
since accumulation of crap is too often the problem with old kit.

I've no experience with clock mending, but from working with other
assorted historical mechanicals this is what I would suspect, rather
than a pendulum length error.

Why would it lose at one piont and keep time the rest? Probably a bit
of muck on only one part of a wheel.


NT

does it lose the 11 minutes over a 12 hour period or does it lose a bit
at a time. I.E. 5 1/2 minutes over 6 hours. There could be a point
where one of the hands is crossing over the other and at a specific
point are misaligned just enough to bind up untill pendulum force
causes them to snap into position. The binding hand could slip on it's
axle untill the pressure was sudennly released. You should get a few
Newcastle Browns and sit and watch it intently untill it happens.""Jim""

Is it a striker. Could be some problem in the cam area.

does it lose the 11 minutes over a 12 hour period or does it lose a bit
at a time. I.E. 5 1/2 minutes over 6 hours. There could be a point
where one of the hands is crossing over the other and at a specific
point are misaligned just enough to bind up untill pendulum force
causes them to snap into position. The binding hand could slip on it's
axle untill the pressure was sudennly released. You should get a few
Newcastle Browns and sit and watch it intently untill it happens.""Jim""

On 13 Jun 2005 09:11:32 -0700, wrote:

Pendulum length is set correctly once only in the life of the clock.

A pendulum will vary its length with temperature, enough to cause
inaccuracy between summer and winter. A few have a compensated
"gridiron" pendulum, but these are pretty rare (and most are just
decorative fakes).

If your clock only ever jumps forwards or back by 11 minutes, then I'd
suspect a loose hand. Does it still strike on the hour ?

If it jumps by this much but sometimes does it twice, then look for wear
allowing endfloat in a pinion. Combined with a less than flat and
perpendicular wheel, this may allow the pinion to jump a few teeth on
the wheel. This same fault can obviously cause the "single jump" too,
especially if it's freshly wound.

The most likely pinion for endfloat problems is the one forward of the
mechanism's front plate, driving the hands.

In general, don't mess with any clock older than WW1. Menders are still
around and they deserve the trade. If it's a post WW2 Smiths or
Perivale, then get the spanners out and go to it.

I have an old (Victorian) pendulum spring wall clock. I finally got it to
keep good(ish) time by adjusting the pendulum length.
Recently it has taking to losing 11 minutes then it continues merrily on
its way not losing any more. It's always ~11 minutes (ie not 8 or 13). If
I
reset it, it will sooner or later do the same thing.
Any ideas?
--
Jim on Tyneside UK


There is clearly a case for setting the clock 11 mins fast - when it will
take to losing 11 mins.
When it continues on its merry way not losing any more - the clock will be
showing the correct time.
My idea !

Pete
www.thecanalshop.com

On Mon, 13 Jun 2005 18:42:38 +0100, Peter Stockdale wrote:

I have an old (Victorian) pendulum spring wall clock. I finally got it to
keep good(ish) time by adjusting the pendulum length.
Recently it has taking to losing 11 minutes then it continues merrily on
its way not losing any more. It's always ~11 minutes (ie not 8 or 13). If
I
reset it, it will sooner or later do the same thing.
Any ideas?
--
Jim on Tyneside UK


There is clearly a case for setting the clock 11 mins fast - when it will
take to losing 11 mins.
When it continues on its merry way not losing any more - the clock will be
showing the correct time.
My idea !

Pete
www.thecanalshop.com

Now that's lateral thinking. )
--
Jim on Tyneside UK
Remove X to email me.
http://freespace.virgin.net/mr.jimscott/

There is clearly a case for setting the clock 11 mins fast - when it will
take to losing 11 mins.
When it continues on its merry way not losing any more - the clock will
be
showing the correct time.
My idea !

Pete
www.thecanalshop.com

Now that's lateral thinking. )

Timely, though.

Mary
--
Jim on Tyneside UK
Remove X to email me.
http://freespace.virgin.net/mr.jimscott/

On Mon, 13 Jun 2005 18:42:38 +0100, "Peter Stockdale"
wrote:

I have an old (Victorian) pendulum spring wall clock. I finally got it to
keep good(ish) time by adjusting the pendulum length.
Recently it has taking to losing 11 minutes then it continues merrily on
its way not losing any more. It's always ~11 minutes (ie not 8 or 13). If
I
reset it, it will sooner or later do the same thing.
Any ideas?
--
Jim on Tyneside UK


There is clearly a case for setting the clock 11 mins fast - when it will
take to losing 11 mins.
When it continues on its merry way not losing any more - the clock will be
showing the correct time.
My idea !

Yes - this appears to be 11 mins backlash in the mechanism. The
pendulum timing seems to be OK, but 11 mins is being taken up by
(probably) wear in the "cogs"!

--
Frank Erskine
Sunderland

Frank Erskine wrote:

Yes - this appears to be 11 mins backlash in the mechanism. The
pendulum timing seems to be OK, but 11 mins is being taken up by
(probably) wear in the "cogs"!

Or maybe its the OP thats losing 11 minutes, not the clock...

NT

or just stop it. then it will be right twice a day which is better
than never being right having lost 11 minutes.

Robert