Pendulum clock runs slowly with pendulum bob all the way up

[pedro_keith]

I have an Hermle wall regulator. The movement is 351 - 830. 66cm 80.166
This clock has not been run for a couple of years and after a move to a new home, it has been sitting. I decided to get it out and try running it. I don't know anything about clocks, but after finding that the clock pendulum would not keep it going, I found a small piece of metal inside the case. After some research, I found that it was a part of a broken suspension spring. I ordered one from Emperor Clock works ( a 351 - which I believe to be correct for my movement?). In any event, it arrived and looked just like the one that was broken. I removed the movement and installed the suspension spring. I read about how to but the movement in beat, and after much adjusting, I now have a very nicely timed tick toc - evenly spaced. I sounds correct. Everything works on the clock - it chimes , etc.
The problem is that is running slowly. About a minute each half hour. I have moved the pendulum bob ( the round weight?) using the screw knob all the way up and it still runs slowly.
The clock will run on its own without the pendulum and I have been letting it run. I suppose my thinking is that letting it run all the way down a few times my loosen up anything that is hanging it up.
Sorry - I'm getting to my questions:
Will letting it run without the pendulum POSSIBLY loosen it up so that it can run correctly? Should I get a shorter pendulum for the clock? I really cannot afford right now to have a professional clean the movement. I'm trying to avoid this. I know that taking it to a pro is the prudent thing to do, but in the mean time is there anything I can do? A different suspension spring? (though the one I purchased is supposed to be the right one I would think. It is a 351 and it looks just like the one that was broken.
Will letting the clock run down without the pendulum a few times help this? Should I take to movement from the case and try and oil some of the pivots?
If I were to get a shorter pendulum, how would I order it? Does the 66 cm refer to the length of the pendulum? Should I just order what I see on the web as one that lists as one I could get as a 55cm, 48cm, 45cm, and on down?
Thank you reading this long post and please let me know what you think.

 

[Willie X]

Your clock may be trying to stop on you ...
It's probably way past dut for a take apart service. This is where the clock movement is disassembled and everything renewed as it once was, bushing work, pivots polished, etc. Changing the suspension spring, for a similar one, should not make much difference in the rate.

Yes, you can remove and surface clean/oil your movement. This might free it up enough to run for a while but does nothing to address the real problems.

For me, clocks should have a check-up and oil top up every 3 to 5 years. When black deposits show up at any of the pivot holes, it needs the 'take-apart' service mentioned in the first paragraph above.

Willie X

 

[R. Croswell]

Pedro, I believe Willie is correct that this clock movement is probably way past due for a take apart service. I also understand that this may be out of reach at this time. There are a few things that you can try to make this clock run faster, but we need to know how strongly it is running now. What is the total swing distance of the pendulum?

If the pendulum is barely moving, you will be wasting your time. If you have a swing of an inch or more you might try replacing the suspension spring with on that is slightly thicker and or shorter. If you replace the round pendulum bob with one that has a smaller diameter, this can raise the center of gravity and cause the clock to run faster. If you add weight (small lead fishing line weight etc.) above the pendulum bob this will also raise the center of gravity and cause the clock to run a bit faster. Once you are able to have the clock properly serviced you may need to undo these modifications so don't lose the parts.

RC

 

[Dick Feldman]

If the clock is running slow and is operating reliably, you might click on the link below for help:
Hermle Clock Pendulum Measuring
The clock may be equipped with the wrong pendulum and the pendulum you have may be able to be modified to suit the clock movement. (Shortened)
There is a date code stamped on the rear of the movement, at the top of the stamping panel. That date code can be a number or letter. That might help with an indication of if service is due.
I do not believe that running the clock without the pendulum will be of any merit.
My opinion is that a Hermle movement should be run till it gives poor service. Normally the lifespan of a Hermle movement will be 20-25 years if it is serviced every few years. If the movement is run without service under normal conditions, it will operate for 20-25 years before failure. That tells me something of the true value of maintaining a clock with cleaning, lubrication, etc. I understand this is in violation of manufacturer's recommendations but the previous comes from a long experience with clock movements. I recommend that a clock be run till it does not give reliable service or to fix it when it is broken. My opinion only and I do not aim to ruffle any feathers.
Best of luck with your clock,
Dick

 

[JayKosta]

I assume the pendulum is the same as what worked with the clock in the past.
I would first remove the movement and do the non-disassembly surface clean/oil that Willy mentioned. That will let you see the condition of the pivots (oval holes mean wear), and to remove old dry / dirty / stiff oil.

I would not try adjustments to the pendulum to make it run faster - that would only make it wear more quickly because of the lack of cleaning and good oil.

 

[JayKosta]

...
My opinion is that a Hermle movement should be run till it gives poor service. Normally the lifespan of a Hermle movement will be 20-25 years if it is serviced every few years. If the movement is run without service under normal conditions, it will operate for 20-25 years before failure. ...

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Are you saying that being 'serviced every few years' doesn't extend the life of good running - that the lifetime will be 20-25 years in either case?

 

[shutterbug]

It is possible, Pedro, that your new suspension spring is much thinner than the original and/or much longer. Either of those things will cause a change in the timing. However, usually you would have enough room on the pendulum rating nut to correct for that.
Is your pendulum 66cm long? Has it been swapped?
We could sure use some pictures of what you have and a video of how it's running. Then we can give you more specific help.

 

[Dick Feldman]

Are you saying that being 'serviced every few years' doesn't extend the life of good running - that the lifetime will be 20-25 years in either case?

Yes, but I should qualify my previous post.
In recent years, it seems the quality of German made movements has declined appreciably.
We have seen this along with bankruptcies, supply problems, etc.
So--maybe 20-25 years is an overestimation of lifespan with current production.
That may be an indication of the future of the two major manufacturers of clock movements in Germany.
Clean, oil and adjust are not bad for clock movements.
Many times those preventative measures are touted to be curative, which they seldom are.
Again, this is my opinion based on many years in the industry.
Let us not cloud this poster's discussion any further and stick to a solution for his clock problem.
Best,
Dick

 

[shutterbug]

Another possibility occurs to me. If this is a Lyre pendulum, perhaps the grid has fallen down. That would cause the issue, and would not be correctable with the bob. Pictures please

 

[Willie X]

When it comes to Hermle movements, DF's observations are corect.

Most clocks will reward you for your routine service efforts. Hermes will not.

I have seen where Hermles, that did get one oiling at around 10 or 12 years, might have made it for a few 'extra' years. This was learned by happenstance, where a 10 year old clocks had something broken and were oiled at the time of repair. But overall ... routine preventive maintenance on a Hermle is a waist of your time/money.

Run it till it drops and do an overhaul, or movement replacement. That's the name of this game.

Willie X

 

[shutterbug]

Yeah ... I've heard of shops recommending a yearly oiling which they usually charge way too much for. That alone can cost well over a complete repair over time.

 

[pedro_keith]

Thank you all so much. Yes, it is the original pendulum and it is the correct length. IF if were to order a different, shorter pendulum would it be a 55cm? I know it's a temporary fix - until I get it cleaned and oiled, or just simply get a replacement movement.
Quick question: would one turn of the knob be one minute per 24 hours?
Thank you again!

 

[Uhralt]

If the movement is in such a bad shape that it cannot keep time with the original pendulum, then using a shorter pendulum will not solve the problem. the clock will not run reliable but erratically be sometimes fast and sometimes slow.

How much one turn of the knob will change how fast the clock runs is different from pendulum to pendulum. The effect is stronger in short pendulums and less strong in long pendulums.

Uhralt

 

[pedro_keith]

Another possibility occurs to me. If this is a Lyre pendulum, perhaps the grid has fallen down. That would cause the issue, and would not be correctable with the bob. Pictures please

It is not a lyre pendulum. Just a straight brass with a round weight at the end. It is the original that came with the clock.

 

[pedro_keith]

If the movement is in such a bad shape that it cannot keep time with the original pendulum, then using a shorter pendulum will not solve the problem. the clock will not run reliable but erratically be sometimes fast and sometimes slow.

How much one turn of the knob will change how fast the clock runs is different from pendulum to pendulum. The effect is stronger in short pendulums and less strong in long pendulums.

Uhralt

Understood. Thank you.

 

[JayKosta]

It is not a lyre pendulum. Just a straight brass with a round weight at the end. It is the original that came with the clock.

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Depending on how the bob is attached to the rod, the bob might be sort of 'stuck' on the rod and just turning the knob might not be enough to move the bob UP. You might need to first lower the knob and then manually push the bob slightly higher and then raise the knob. If you do that be very careful to NOT pull or twist the rod - treat it carefully.

It's very likely that at a minimum, the movement needs to be removed and have a 'surface' clean / oil and inspection.

 

[Dick Feldman]

It is past time for pictures and/or videos.
With the information given, the clock should keep time.
i.e. original pendulum, exact replacement of suspension spring, etc.
Running slow with a pendulum movement is not a normal symptom of wear, dirt, lack of lubrication or being out of adjustment. It is a symptom of a pendulum that is too long.
Worn clock movements will normally stop running, not run slow.
JMHO,
Dick

 

[R. Croswell]

It is past time for pictures and/or videos.
With the information given, the clock should keep time.
i.e. original pendulum, exact replacement of suspension spring, etc.
Running slow with a pendulum movement is not a normal symptom of wear, dirt, lack of lubrication or being out of adjustment. It is a symptom of a pendulum that is too long.
Worn clock movements will normally stop running, not run slow.
JMHO,
Dick

I generally agree, but I have had clocks come in, usually after they quit running, where the owners had set the rate adjustment to full fast or raised the pendulum bob above where it needed to be to keep time after service. Sometimes things do not act as expected. My theory is that thickened oil and dirt can make the escape wheel sluggish to move when the teeth are released causing the escapement to "hold back" the pendulum, just as we see freshly wound spring powered clock escapements "push" the pendulum faster than its natural rate. It all comes down to the fact that one cannot properly adjust a worn or dirty clock movement.

RC

 

[Dick Feldman]

This is true. If the cause were known, the solution would be pretty straight forward.
Maybe the pendulum/leader/suspension spring has been assembled incorrectly.
At this point, photos or videos will be of help.
Dick