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400-day clock - how long should I test?

Simon Holt

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Mar 21, 2017
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I'm working on a 400-day clock (which I rarely do), which I've been having trouble getting to run for any length of time (45 minutes max).

I finally had a breakthrough when I decided to lower the fork (having read a hint on the message board), and got it up to 18 hours. I've lowered the fork some more and hopefully it will last even longer. I've re-adjusted the beat for equal overswing in both directions, by the way.

My question is: at what point can I regard this as ready to go back to the owner? If it is still running after 7 days, would that be enough?

Simon
 

KurtinSA

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Simon -

I routinely test my clocks for 360 days before I consider it good! Just kidding! This is a tough one. I don't have customers so I'm only satisfying myself. I usually get the clock to run without motion works for 12-24 hours, then another 12-24 hours with hands and motion works. If the swing parameters are solid with good amounts of over swing, I call it good. That said, after "clearing" a clock this way, I've found them stopped a few days to a few months later. The issue is that it takes some amount of time before all of the teeth/pinions have a chance to touch each other at least once. I believe a main spring barrel takes at least a couple of months to make a complete revolution.

But to answer your question, if a clock ran strongly for 7 days, I'd be inclined to call if fixed. But the warranty period might be a biyotch! :D

Kurt
 

Simon Holt

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Simon -

I routinely test my clocks for 360 days before I consider it good! Just kidding! This is a tough one. I don't have customers so I'm only satisfying myself. I usually get the clock to run without motion works for 12-24 hours, then another 12-24 hours with hands and motion works. If the swing parameters are solid with good amounts of over swing, I call it good. That said, after "clearing" a clock this way, I've found them stopped a few days to a few months later. The issue is that it takes some amount of time before all of the teeth/pinions have a chance to touch each other at least once. I believe a main spring barrel takes at least a couple of months to make a complete revolution.

But to answer your question, if a clock ran strongly for 7 days, I'd be inclined to call if fixed. But the warranty period might be a biyotch! :D

Kurt
Thanks Kurt. They can be finnicky, that's for sure. Are you also of the view that the lower the fork the better, as long as no fluttering occurs?

Simon
 

KurtinSA

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Yes, Simon, that is the mantra! I have been stumped with a clock and then figure the only thing I can do is lower the fork...boom...the clock runs. I don't do the "lower until flutter and raise it a bit" process. If I lower it and the clock performs better, I might call it quits. As you said they are finnicky. Seems that whenever I get my fingers into these things, stuff goes wrong. The goal is over swing, say on the order of 30-45 degrees. If you get that, take it and run...accept whatever total rotation you have. It's "pretty" to see 270 or 360 degrees of total swing...me, I just want them to have good over swing.

Edited!

Kurt
 
Last edited:

Dells

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Hi Kurt
Did you mean to say 270 to 360 deg over swing , I think you mean total swing
I usually lower the fork to flutter then edge up until I have no flutter if it will not run setup as the book states.
Dell
 

Wayne A

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I like to set my 400 day clocks to run with 1 turn on the mainspring, soon as it runs reliably for a couple of days I wind it fully and see if it still runs properly for a couple of days. If good it's moved to a shelf.
The fork has a range of acceptable positioning, there is a too low and too high. Thing about too low is swing will begin to reduce because the impulse is absorbed in the suspension spring with less energy transferred to the pendulum. To high and the swing is also reduced and will get to the point that the escapement no longer can advance against the short rigid suspension spring above the fork. Flutter begins to be more likely with lower fork settings as well. Flutter can be a real pain and not easy to even notice, clock can run a month then one day decide to flutter a few minutes and then run fine for weeks. So a little flutter is easy to overlook and think its just running a bit fast. To help check for flutter I initialy set clocks with stopwatch or electronics, so if the time is fast recheck with stopwatch or electronics before adjusting to see if its actually fast and not flutter.

Wayne
 

Schatznut

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It depends on the nature of the fault I'm trying to correct, and how confident I am in its condition when watching it run. Keeping in mind I'm a hobbyist and not a professional, I agree with the common-sense wisdom above.

If it will freewheel with no more than two clicks, that's a good indicator it's clean, no bent parts and has minimum friction. Wayne's metric of running correctly with one turn of the mainspring also indicates the escapement, anchor, fork and suspension spring are set up well. This should be with the minute and hour cannons and hands, tension washer(s) and idler gear installed.

I like to see it run for 30-45 days so that it gets at least one complete turn of the mainspring barrel. I had one that ran perfectly, with lots of power and overswing, and then suddenly died for no easily discernible reason after about 30 days. Upon inspection under a microscope, it had almost imperceptible damage to a single tooth on the mainspring barrel. A couple of quick passes with an abrasive stick and it has lived happily ever after. Unfortunately it was a clock I'd given to a friend as a gift and it was quite embarrassing to have to take it back and go through it again. But living with embarrassment as an amateur was much easier than if I had done it professionally.
 

Simon Holt

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This is all very useful information to someone like me with little experience. I've got a couple going before but never had to mess with fork height. Why would it need to be different from how it came from the factory? I don't think anyone had messed with it before it came to me.

I'll get it back to the owner if it runs for 9 days; they live close (and I'm not charging them) so if it has to come back it's no problem.

Thanks again.

Simon
 

KurtinSA

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Why would it need to be different from how it came from the factory? I don't think anyone had messed with it before it came to me.
Good question! Let me know when you find out!! I'm sure it comes down to just wear and tear. These clocks don't have the over powered systems like other 8-day, 30-day type clocks. That's good in that there tends to be little wear. But when there is some, and they do wear, that creates problems. Anniversary clocks have very limited power over and above the friction that's there. So, in order to compensate for the wear, one might have to change the settings. More power is required for a high mounted fork, so lowering the fork can help to rebalance things. The fork tines are critical as well. Grabby fingers and handling them can change how tightly they surround the anchor pin...maybe changes need to be made to account for that. I think these issues are reasons some professional repair shops won't touch anniversary clocks.

Kurt
 

Schatznut

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You can't be sure that a new suspension spring you've installed is made of the same material as the one you're replacing, and the stiffness of the spring will go hand-in-hand with the fork height. I install Horolovar springs exclusively and use the suspension assembly templates in the book as guidelines, but frequently tune the location of the fork. I look for the onset of flutter and use that as the lower bound, then move it up until it has good rotation (270 degrees or better). Then I look at the amount of supplementary arc with the mainspring wound two turns or so as an indicator of how long it's going to run with the fork in that position. If I see 30 or more degrees of supplementary arc, I know there's adequate power available. If it doesn't exhibit good supplementary arc, I lower the fork a little until it does. This is by no means an exact science but it generally gives good results. It's also an iterative and somewhat fiddly process, and one must check the beat after each adjustment. Plus there's always the risk of damaging the spring while removing, adjusting and reinstalling. I can understand why the pros wouldn't want to dink around with 400-day clocks - the risk/reward ratio is too high and the return on time invested is too low (high risk; low reward) if you're trying to put food on the table.
 

Simon Holt

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Thanks again to everyone for the additional guidance. I'm guessing you've worked on dozens, if not hundreds, of this type of movement.

I realize I can't expect to hit the ground running after working on only three of these, so all of this information is going to help avoid future frustration :banghead:. I'm reluctant to buy a book on the subject because I'm rarely asked to work on one of these (I'm a hobbyist so I typically only get one clock a week to look at). Incidentally, I haven't replaced the suspension spring in this one - there were no kinks or twists so I was assuming it was more or less exactly how it came from the factory in terms of its performance characteristics.

This particular clock has been running for 27 hours since the last lowering of the fork height, which is 9 hours longer than the last test. Fingers, toes and other bits crossed...

Simon
 

Schatznut

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When yo pointed out you haven't replaced the suspension spring, I realized you haven't described what you've done to this clock to get it to the point where it's reluctant to stay running. That information would help us help you diagnose it. If you haven't replaced the suspension spring there's no reason you should have to adjust the fork. As others have pointed out, lowering the fork increases the power going to the pendulum at the expense of pendulum rotation. If you've made it run better by lowering the fork, you're treating a symptom, not curing a disease. You need to figure out where the power is being lost in the first place.
 

Schatznut

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As I continue to find out, this is easier said than done! ;)

Kurt
Roger that - it's kind of an "Indiana Jones and the Quest for the Lost Power" thing. My problem is that my Indie hat keeps getting caught in my magnifying lamp!

The one-click freewheel test and the one-turn operational test are the ones that give the best indication of overall movement health. Then, once it stalls, there are a few things that can be done to diagnose why the power is not being transmitted to the pendulum efficiently.
 

MuseChaser

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........ Then, once it stalls, there are a few things that can be done to diagnose why the power is not being transmitted to the pendulum efficiently.
(....waiting with baited breath...)

Do continue! :) I've successfully done about 25 various torsion clocks at this point, but would love to learn more about a more methodical approach to troubleshooting. My current approach is ..

1. Doesn't run?
2. Take it completely apart, clean everything thoroughly and carefully, replace anything missing or broken, reassemble.
3. 2-click/no escape test for power.
4. Add escape, 3/4 wind, get in beat, adjust fork as needed. Adjust escape only if obviously incorrect and/or evidence of previous skullduggery.
5. Success? Great. Failure? Repeat.

Of the 25 I've done, after six months I have three I need to revisit. Not bad for a beginner, I guess, but a more targeted/less shotgun approach to these three will probably be helpful....if not downright necessary.

Thanks, Schatznut.
 

Schatznut

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(....waiting with baited breath...)

Do continue! :) I've successfully done about 25 various torsion clocks at this point, but would love to learn more about a more methodical approach to troubleshooting. My current approach is ..

1. Doesn't run?
2. Take it completely apart, clean everything thoroughly and carefully, replace anything missing or broken, reassemble.
3. 2-click/no escape test for power.
4. Add escape, 3/4 wind, get in beat, adjust fork as needed. Adjust escape only if obviously incorrect and/or evidence of previous skullduggery.
5. Success? Great. Failure? Repeat.

Of the 25 I've done, after six months I have three I need to revisit. Not bad for a beginner, I guess, but a more targeted/less shotgun approach to these three will probably be helpful....if not downright necessary.

Thanks, Schatznut.
Once it stalls, then the serious troubleshooting can begin.

Is an anchor pallet in contact with the escape wheel?
Yes - then the problem is at ir downstream of the escape wheel. Out of beat, bent anchor pivot, bent anchor pin, tight fork, kinked suspension spring, incorrect fork location, bent escape wheel teeth, pallet drop incorrect. Don't mess with the pallet drop unless you know there's a problem with it and know how to fix it. 99% of the time you can only succeed in making things worse.
No - then the problem is upstream of the escape wheel. Using a fine stylus and starting at the escape wheel, gently rock the wheels back and forth one at a time until you get to a wheel that doesn't move. Something in that wheel or its mesh with the wheel below it is binding.
 

Simon Holt

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I realized you haven't described what you've done to this clock to get it to the point where it's reluctant to stay running.
The clock came to me in a non-running condition (well, 15 minutes maximum).

There was a lot of pivot poop, so I did a full dis-assemble, ultrasonic clean, two bushings, mainspring out and cleaned. I didn't do anything with the suspension spring at all.

Simon
 

KurtinSA

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Once it stalls, then the serious troubleshooting can begin.

Is an anchor pallet in contact with the escape wheel?
Yes - then the problem is at ir downstream of the escape wheel. Out of beat, bent anchor pivot, bent anchor pin, tight fork, kinked suspension spring, incorrect fork location, bent escape wheel teeth, pallet drop incorrect. Don't mess with the pallet drop unless you know there's a problem with it and know how to fix it. 99% of the time you can only succeed in making things worse.
No - then the problem is upstream of the escape wheel. Using a fine stylus and starting at the escape wheel, gently rock the wheels back and forth one at a time until you get to a wheel that doesn't move. Something in that wheel or its mesh with the wheel below it is binding.
I'm not sure how one can eliminate the "upstream" part of the clock if the pallet is resting on the escape wheel. Yes, there might be something wrong with the escapement, but I see this situation as lack of power (or excess friction) anywhere in the clock. Couldn't a problem be weak power coming from the main spring or arbors lower in the train? It takes "push" from the main spring for the escape wheel to ride along the impulse face. So, it could be lower in the train IMO. I just finished working on a Hall Craft clock...pretty cheaply made. I was getting limited rotation and barely enough over swing. It would always stop with an escape wheel tooth on the pallet. If I slowly turned the pendulum to continue the swing, the tooth dropped off the pallet. In the end, I evaluated the entire train and found at least the first two arbors with excessive pivot movement in the holes in the plate. I chalk that up to needing a bushing and put the clock up until I'm ready to try that type of "fix".

Kurt
 

shutterbug

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I'd let it run for two weeks. If no issues, send it back home. It will likely keep running if it went that long. If it doesn't, you have other issues somewhere in the power train. It's also a good idea to test clocks on minimal wind so you're not masking power issues.
 

KurtinSA

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I'd let it run for two weeks. If no issues, send it back home. It will likely keep running if it went that long.
Maybe! It takes the main spring barrel at least a couple of months to make a full revolution. I don't have the numbers on all clocks, but the first arbor can take 2-3 weeks to rotate once. For me, I'm hoping I found the problem on one of miniature Kundos. It would only run for 4-6 weeks at a time no matter what I did. Hearing some others mention individual arbor inspection...and realizing I haven't been doing that...made me try yet again on this Kundo. WTF! A bent tooth on the first wheel!! That can't help but it did run for some amount of time. I did my best to straighten things and hope it fixes this situation. I'll know in a month or so!!

Kurt
 

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