Extending run time of 24 hour clock

mr_byte

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I picked up a clock from a customer recently, he'd like to make it run longer than the 24-30 hours it has.

I know that some will say "Change the gears" or "OMG that's BLASPHEMOUS!!!" ;) but what I was thinking was that a change in spring length (longer) and possibly a tad thicker would get me an extra 2 or 3 days.

I do not want to re-gear or modify the movement in any other way.

Opinions? Please no flames....

Jeff
 
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R. Croswell

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I picked up a clock from a customer recently, he'd like to make it run longer than the 24-30 hours it has.

I know that some will say "Change the gears" or "OMG that's BLASPHEMOUS!!!" ;) but what I was thinking was that a change in spring length (longer) and possibly a tad thicker would get me an extra 2 or 3 days.

I do not want to re-gear or modify the movement in any other way.

Opinions? Please no flames....

Jeff
If it's an open spring American clock you might go with a longer THINNER spring (if you can find one) and gain a few more hours. The best advice I have would be to trade the clock for one that's designed to run for 8 days or longer. If it's not a valuable antique, you could put in a quartz movement. .......Did I say that?

RC
 

Tinker Dwight

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Hi
It is not likely that there is enough room for
a spring long enough to give it much more than a few
hours longer.
To go days, you can do what some manufactures
have done. They create an outrigger to hold
the new spring. The then replace the original
spring with a pinion.
Do remember, turn in equals turns out.
The number of turns a clocks spring gets
will be the same as the number of turns running,
with the possible loss on first winding of the
spring taking a set.
To get it to be an 8 day, you'd need to us a spring
that was longer and thicker on the new arbor.
As I recall, the spring will get stiffer by the square
of the thickness. Any additional run time would
need to be the spring length and matching ratio
of the gears.
It is possible to keep the springs where they are.
This could be done by moving the pinion on the
wheel next to the spring and then placing the
ratio and idler wheels on the out rigger.
That would be a minimum modification to the case,
assuming there was room in the case for the out rigger.
Tinker Dwight
 

mr_byte

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If it's an open spring American clock you might go with a longer THINNER spring (if you can find one) and gain a few more hours. The best advice I have would be to trade the clock for one that's designed to run for 8 days or longer. If it's not a valuable antique, you could put in a quartz movement. .......Did I say that?

RC
Quartz!!!?!!!11!!!!eleven!!:???: <Gasp!> ;-)

I thought a thinner spring would be a bit weaker, and make the clock run too fast (weak spring, low power at EW, pendulum has shorter swing...) but a thicker one would compensate for the possible loss of strength caused by a longer spring.

I think I should have kept my mouf shut when the customer asked and will probably return the clock to the customer, as it really sounds like we'd not get enough extra time to make it worth while. If I had some springs here to test with, sure, but I'd have to order in some from Timesavers.
 

Tinker Dwight

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Hi
Regardless of the strength of the spring, to make it
run for an additional day would require a spring
that was roughly twice as long.
If the same thickness, some bigger around. Not
twice because it is added at the outside diameter.
Maybe 20% more. I'd need to give it some thought.
To get the same tension, it'd need to be about 40% thicker
as well( if my math is correct ).
I think the out rigger idea has merit. It is possible to
make it work with out any modification to the clock
other than removing the spring and finding another
location to wind the movement.
Tinker Dwight
 

Willie X

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Mr B,

You can spend a lot of time and maybe increase the run time a bit. My question is why? Best you could hope for would be close to maybe 2 days.

Bottom line is that a one-day (or two-day) clock is not very practical in today's world.

My advise would be to leave this clock as is and spend your time looking for an 8-day clock that you like.

Willie X
 

mr_byte

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I like the outrigger idea, to hold the end of the spring. I'm not completely following it though.

Mr B,

You can spend a lot of time and maybe increase the run time a bit. My question is why? Best you could hope for would be close to maybe 2 days.

Bottom line is that a one-day (or two-day) clock is not very practical in today's world.

My advise would be to leave this clock as is and spend your time looking for an 8-day clock that you like.

Willie X
It's not my clock, but a job I took on from a customer. Likely it'll just go back with an "I'm sorry, I didn't think this through" to them. I do have a 30 hour here I may experiment with on my own, as it's mine. I'd rather find some old beat up 30 hour for that, however.
 

Steven Thornberry

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I have to wonder why the customer wants this done. A longer thicker spring might actually be more than the movement will bear. He/she could always wind it twice a day to produce the illusion of a longer run time.:)
 

LaBounty

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I did this with one of my own 30h clocks which was missing mainsprings and ended up with 3-days run. Using the spring length formula normally applied to mainsprings in a barrel, one can determine how long a mainspring should be in order to fill the available space.

The value for the ID of the barrel in the formula would be twice the distance from the center of the main wheel arbor out to the closest obstruction, usually the second wheel pinion. The original thickness of the mainspring can be used in the calculation but a couple of thousandths thinner would allow for a much longer mainspring and push the run time out to the 3-day time frame, provided the movement is in good order.

Of course, a customer isn't likely to remember to wind the clock every three days so there's not much advantage to doing this. And I don't believe it is possible to extend the run time out to even 7-days by installing a longer/thinner mainspring. As RC says, it would be better to buy one which is designed to run that long :).

Hope that helps!
 

Watchfixer

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Servicing the clock will extend the run time from 24hr to around 30 hr or so.
Then tell owner to get in habit of winding it every morning or before bedtime by posting a note reminder. Eventually habit become set.

Cheers, Watchfixer
 

shutterbug

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I'm thinking you may have a good opportunity for a trade. If you have a newer 8 day clock in your inventory that you'd consider trading for the older one day, and could still come out ahead, you might present him with that idea.
 

mr_byte

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I did this with one of my own 30h clocks which was missing mainsprings and ended up with 3-days run. Using the spring length formula normally applied to mainsprings in a barrel, one can determine how long a mainspring should be in order to fill the available space.

The value for the ID of the barrel in the formula would be twice the distance from the center of the main wheel arbor out to the closest obstruction, usually the second wheel pinion. The original thickness of the mainspring can be used in the calculation but a couple of thousandths thinner would allow for a much longer mainspring and push the run time out to the 3-day time frame, provided the movement is in good order.

Of course, a customer isn't likely to remember to wind the clock every three days so there's not much advantage to doing this. And I don't believe it is possible to extend the run time out to even 7-days by installing a longer/thinner mainspring. As RC says, it would be better to buy one which is designed to run that long :).

Hope that helps!
It does indeed help. Thanks!

I'm thinking you may have a good opportunity for a trade. If you have a newer 8 day clock in your inventory that you'd consider trading for the older one day, and could still come out ahead, you might present him with that idea.
I don't think I have anything I'm wanting to part with. It's a nice clock, but it's not to my taste. I run more to gingerbread or wooden movements, with a sprinkling of column-fronted mantles and banjos :D

I'll tell him that 3 days would be the absolute max, with 2.5 days more likely and let him make the call from there. In any case he gets his old springs back so if he should sell it later on, they can return it to stock.
 

Willie X

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Of course, a customer isn't likely to remember to wind the clock every three days so there's not much advantage to doing this. Hope that helps!
This is what I have seen also. Winding every day is much easier to remember. However, it is very handy for a clock to run about 38 hours. That way the customer can wind it most any time of each day, without it stopping.

Willie X
 

mr_byte

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This is what I have seen also. Winding every day is much easier to remember. However, it is very handy for a clock to run about 38 hours. That way the customer can wind it most any time of each day, without it stopping.

Willie X
Indeed. I have a groaner here I may put pulleys and larger weights on to increase it's run time just for that reason, though I have an Ogee I'll try that on first, since brass is a bit easier for me to work with than wood...
 

R. Croswell

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Indeed. I have a groaner here I may put pulleys and larger weights on to increase it's run time just for that reason, though I have an Ogee I'll try that on first, since brass is a bit easier for me to work with than wood...
mr_byte, heavier weights won’t make the clock run any longer. It’s how far the weights can fall that determines how long the clock will run. The problem with a weight clock is that there is only so much room on the spool to wind up the cord or cable. The weights exert exactly the same driving force regardless of it they are at the top of the clock or near the bottom. Your 30 hour OG is only going to run 30 hours regardless of if it has 2 lbs. or 10 lbs. of weight. You may be thinking that if you can get the pendulum to swing a wider arc that the clock will run slower and therefore longer. That is true but the clock also will not keep time and the rate change will be very small.

You will have a better chance eeeking out a few more hours with the spring powered clock. The first thing is to make sure it is in perfect condition and all the pivots are smooth and no worn pivot holes. It will probably run for two days if you do nothing else to it. A thicker spring will add nothing to the run time. The length of the spring is what counts. Most American clocks are over powered, so using a thinner spring should still give it enough power to run, and being thinner will allow it to be longer and take up the same space. You will probably have a problem finding a spring that is significantly longer than what you have. Another point to consider is that if you push a clock like this to run longer than intended, like until just before it stops, it will likely start loosing time badly near the end of the run. Another problem with letting the clock run out to the end is that the over-expanded spring may interfere with the strike hammer lever or rub against an arbor and stop the clock.

You could try Nano Oil on the pivots and spring and see how that works as well.

RC

 

doug sinclair

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I recently serviced an 8-day office wall clock, including a new mainspring of the same dimensions as the tired original. It ran 5 days on a full wind! This was a Canadian-made Pequegnat clock with open mainsprings, a la Connecticut clocks. The problem was simple to solve, resulting in a clock that was running strong after 12 days. As the spring ran down, it eventually expanded to the point that it was rubbing on the pinion of an adjacent train wheel. I installed a simple post in a blank hole in the plate (there may have originally been a post there) to ward off the expanding mainspring, and problem solved. How long does the train of this clock run if you remove the pallets and let it run? If it runs for substantially more than 24-hours, there might be a problem the solution to which will give you a longer run. I am a great believer in replacing "tired" mainsprings. Often, a new spring will cure a problem of reduced run times.
 

mr_byte

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mr_byte, heavier weights won’t make the clock run any longer. It’s how far the weights can fall that determines how long the clock will run. The problem with a weight clock is that there is only so much room on the spool to wind up the cord or cable. The weights exert exactly the same driving force regardless of it they are at the top of the clock or near the bottom. Your 30 hour OG is only going to run 30 hours regardless of if it has 2 lbs. or 10 lbs. of weight. You may be thinking that if you can get the pendulum to swing a wider arc that the clock will run slower and therefore longer. That is true but the clock also will not keep time and the rate change will be very small.
By adding a pulley and having the cord loop thru the pulley and hook to the case at the top, where the existing pulley in the case is, it would nearly double the amount of cord, thus nearly doubling the run time. I'm allowing for the 1 or 2 inches of drop the new pulley would take up.

The extra weight is needed as the "working" weight is halved by the addition of the pulley that the weight would hook to. It may be possible that the clock would run properly on the existing weight, I suppose, depending on it's condition, and if the weight in use was just a "throw it in there it's more than enough" weight and not something the maker calculated to be the minimum needed to run the movement.

Weight by itself would not increase run time, as you noted.

I recently serviced an 8-day office wall clock, including a new mainspring of the same dimensions as the tired original. It ran 5 days on a full wind! This was a Canadian-made Pequegnat clock with open mainsprings, a la Connecticut clocks. The problem was simple to solve, resulting in a clock that was running strong after 12 days. As the spring ran down, it eventually expanded to the point that it was rubbing on the pinion of an adjacent train wheel. I installed a simple post in a blank hole in the plate (there may have originally been a post there) to ward off the expanding mainspring, and problem solved. How long does the train of this clock run if you remove the pallets and let it run? If it runs for substantially more than 24-hours, there might be a problem the solution to which will give you a longer run. I am a great believer in replacing "tired" mainsprings. Often, a new spring will cure a problem of reduced run times.
It doesn't seem tired, he just was interested in extending it's run time. It needed to have the beat set, and in talking about he asked if the run time could be extended, and I said I believed replacing the springs could make it run for more than it's designed 24-30 hours, but that it would not be possible to extend it to a full 8 days, possibly 4 or 5.

It's more a "hack" (in the computer geek sense of the word) than a repair, trying to coax more out of it than intended. Without extensive un-reversible modification.

If I can coax my dead computer into some semblance of life, I can get his info out and call him to see if the possibly 3 days run time is worth it to him.
 
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R. Croswell

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By adding a pulley and having the cord loop thru the pulley and hook to the case at the top, where the existing pulley in the case is, it would nearly double the amount of cord, thus nearly doubling the run time. I'm allowing for the 1 or 2 inches of drop the new pulley would take up.

The extra weight is needed as the "working" weight is halved by the addition of the pulley that the weight would hook to..........
That is true, but you end up with twice as much cord to spool when you wind the clock. As previously stated, there is only so much room on the spool. You will end up with a second layer of cord on the spool and this frequently causes tangling problems. You might get away with it but it is not good practice and may cause you grief.

One thing you might try is a type of fishing line called "Spider Wire" which is available at Wal-Mart. It's probly less than half diameter of regular weight cord and has a test strength of something over 50 pounds. It's very flexable and I have used it on a couple of clocks in the past. That should give you twice as many wraps before the spool is full. Of course that wont help if the spool has grooves for each wrap. At best a one pulley compound system will only get you from 30 hours to 60 (assuming you can find a lead weight that is twice as heavy and no taller than the original) but I'm not sure the gane is worth the trouble. And you will add the problem of trying to remember do I need to wind today or tomorrow.

RC
 

mr_byte

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That is true, but you end up with twice as much cord to spool when you wind the clock. As previously stated, there is only so much room on the spool. You will end up with a second layer of cord on the spool and this frequently causes tangling problems. You might get away with it but it is not good practice and may cause you grief.

One thing you might try is a type of fishing line called "Spider Wire" which is available at Wal-Mart. It's probly less than half diameter of regular weight cord and has a test strength of something over 50 pounds. It's very flexable and I have used it on a couple of clocks in the past. That should give you twice as many wraps before the spool is full. Of course that wont help if the spool has grooves for each wrap. At best a one pulley compound system will only get you from 30 hours to 60 (assuming you can find a lead weight that is twice as heavy and no taller than the original) but I'm not sure the gane is worth the trouble. And you will add the problem of trying to remember do I need to wind today or tomorrow.

RC
I have some rather small diameter fishing leader wire, it's coated, but I was thinking of trying it out on a 30 hour sometime. I originally got it for control cable on my R/C airboat; it did well there, when the engine was running properly...

And true there's not much gain, I'd likely wind it daily. But it'd be more like an insurance policy, if I went out of town overnight, etc.
 
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Jay Fortner

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I was checking this thread out a couple days ago and didn't feel I had anything to add but this morning I had a revelation(my brain's DSL is down some times). I have an old victrola that uses three springs in three drums. The first spring winds the second which winds the third. All three spring have the same power but by interconnecting them gives three times the run time. No reason why you couldn't use four.(or five) It would require redesigning the winding arbor and of course extending that portion of the plate but it could be done.(I think) Downside would be the length of time it takes to wind them all up,may want to put a crank on it or the poor guy may forget what he was doing bout half wind.
 
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R. Croswell

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I was checking this thread out a couple days ago and didn't feel I had anything to add but this morning I had a revelation(my brain's DSL is down some times). I have an old victrola that uses three springs in three drums. The first spring winds the second which winds the third. All three spring have the same power but by interconnecting them gives three times the run time. No reason why you couldn't use four.(or five) It would require redesigning the winding arbor and of course extending that portion of the plate but it could be done.(I think) Downside would be the length of time it takes to wind them all up,may want to put a crank on it or the poor guy may forget what he was doing bout half wind.
Have you ever worked on a "Patti" clock movement? They have two springs in the same floating barrel that are connected at their free ends and both wind from the center. Acomplishes the same thing as your revolation. They are a b---- to work on so I'm sure you would remember if you ever encountered one. If I never see another one will be too soon but it is an inovative design.

RC
 

Watchfixer

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Jay Fortner, a high end wristwatch maker employs same trick of using three mainsprings in series for 8 day run. There is some on youtube about that.

Cheers, Watchfixer
 

mr_byte

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I was checking this thread out a couple days ago and didn't feel I had anything to add but this morning I had a revelation(my brain's DSL is down some times). I have an old victrola that uses three springs in three drums. The first spring winds the second which winds the third. All three spring have the same power but by interconnecting them gives three times the run time. No reason why you couldn't use four.(or five) It would require redesigning the winding arbor and of course extending that portion of the plate but it could be done.(I think) Downside would be the length of time it takes to wind them all up,may want to put a crank on it or the poor guy may forget what he was doing bout half wind.

Waaay beyond my capabilities...but that would indeed be a neat trick.

The spring fully wound has a diameter of 1 inch. It is .016 thick. The arbor is .198. The mainwheel diameter is 2.5 inches and that is where the closest obstruction is.

For room, I'm figuring on 2 inches ID for the formula (which I need to hunt down...) and going with .014 or so. Depending on what TS has.

---Later----

Ok, this spring is 3/8" wide, .375 or a little more, allowing for my micrometer. The longest spring in that width TS sells is 96" long, but it's .017 thick. I wanted to go thinner as this was the wisdom of those that replied, but I originally thought that to keep the same strength over a longer spring, it'd need to be thicker.

I guess what I'm looking for is an opinion on using the 1/1000th thicker spring. The length formula says that 2" diameter would need ~91 inches at .017, 96" gives 2.02" diameter.

McMaster Carr has .015 3/8" blue spring steel, after reading the skeleton clock thread it would appear that's what was used in there to make the fusee spring. The 25ft roll is a touch more than a pair of 96" springs from TS.
 
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R. Croswell

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McMaster Carr has .015 3/8" blue spring steel, after reading the skeleton clock thread it would appear that's what was used in there to make the fusee spring. The 25ft roll is a touch more than a pair of 96" springs from TS.
I believe the 0.015" thick spring should run your clock just fine if it is otherwise in good condition. It is no big deal to put the loop end on, so you might start with a little longer than 96" and see how it works, you can always cut a little off if need be. Generally, it's the length that gives the run time and the thickness that gives the force. But keep in mind that with any spring, it will develop less power as it runs down, so at some point you reach a place where too thin a spring simply will not have enough power to run the clock if it is too far run down. That point is some where in uncharted water and depends on just how much power your particular clock requires to keep going.

I don’t know what widths McMaster has available or if you have any space to make the spring wider. The extra width will accomplish about the same thing as extra thickness – develop a bit more force. Of course it the spring rubs or binds, that would defeat the purpose.

RC
 

mr_byte

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A good test would be to make one up and give it only one turn of wind.
Never thought of buying 25' rolls,that's good research.
Well, it's more than buying a pre-made spring at TS, at least for 3/8 width x 96" long. I went ahead and got them from Timesavers, opting for priority mail, since I've been sitting on this job a bit long. I had to find and buy a battery for my micrometer, of all excuses...

I suspect that McMaster's has wider blue spring steel in the needed thicknesses and that the 100' rolls might be worth it, if one wanted to make their own springs. I don't presently, since I have a lot of larger/wider springs for 8-day movements. The thread on the skeleton clock showed how to make a spring, and it didn't seem complex, basically anneal both ends, make a hole and bend the center, then make a hole or a loop. I may give this a whack on the next project, because it turns out I have a similar Seth Thomas 30 hour myself (I knew this clock looked familiar...) out in the garage.
 

mr_byte

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I don’t know what widths McMaster has available or if you have any space to make the spring wider. The extra width will accomplish about the same thing as extra thickness – develop a bit more force. Of course it the spring rubs or binds, that would defeat the purpose.

RC
Hey RC,

I was thinking of going to 7/16 width, but TS didn't have anything that would improve on the 3/8 in length.

But, I think I will get some steel from McMaster and play when I start experimenting with mine. Looking at it from a resale point of view, making a spring would be faster for turnaround than waiting on the Post-hole service to get it to me from Arizona ;-) and since I believe McMaster has a warehouse in ATL, it only takes a day to get here usually.
 

Jay Fortner

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I searched McMasters-Carr and didn't find the spring material your talking about. In what section did you find it in?
-> posts merged by system <-
I found it,pricey stuff unless you buy 100'. Makes you wonder how Tsavers can sell them premade so cheap.
 

mr_byte

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I searched McMasters-Carr and didn't find the spring material your talking about. In what section did you find it in?
-> posts merged by system <-
I found it,pricey stuff unless you buy 100'. Makes you wonder how Tsavers can sell them premade so cheap.
What I found wasn't too much higher than TS. I figured 25' would make 2 96" springs (it'll do 3, actually.) so for what I needed it was only a buck or 3 higher.

But I'm sure TS buys theirs from China or India...
 

Tinker Dwight

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Hi
I did some spreadsheet calculations to see what going from
0.017 to 0.015 would buy you in increased time.
It would add about 12% longer run.
If the clock was running for 30 hours before, you'd
get about 33 1/2 hours for the change.
Maybe not enough to make the customer happy.
Tinker Dwight
 

mr_byte

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Hi
I did some spreadsheet calculations to see what going from
0.017 to 0.015 would buy you in increased time.
It would add about 12% longer run.
If the clock was running for 30 hours before, you'd
get about 33 1/2 hours for the change.
Maybe not enough to make the customer happy.
Tinker Dwight
Not only thicker, but longer as well.
 

Tinker Dwight

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Hi
It the clock a barreled spring or open. This changes
things.
Barreled spring will have a specific length for each thickness
that will give a maximum number of turns. If you put a
longer spring in the barrel, you'll actually reduce the number
of turns.
Open springs are different but still have similar problems.
You seemed to indicate that it had a restricted diameter when
unwound.
To make a significant difference you may still need to use
more wheels to get the number of turns.
I'll try to make it a little clear. If the spring is already at
the optimal length for the space it has to unwind, making it
longer can even reduce the number of turns( reducing the run time ).
I calculated changing from an optimal 0.017 spring ( the size you
stated you had ) to an optimal 0.015 spring ( the size you said
you were trying ). I used a model that was a barrel that optimized
the unwinding ( in other words it did the best it could and didn't
even allow for a number of free turns, not against the barrel or
arbor at the end of the wind ).
It showed that this change with the optimal spring length could only
increase the run time by 12-13%.
The reason why a spring that is longer may not give you a longer
run time is that you may run out of space to put the unwound
spring before all the energy of the spring is delivered to the clock.
For your arbor and 2 inch largest diameter, the optimal spring length
for a 0.017 spring is about 92 inches.
For a 0.015 spring it is about 104 inches.
Using an even longer spring will decrease the run time because there
isn't enough room to unwind into.
Tinker Dwight
 
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mr_byte

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Nov 25, 2009
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It's an open spring. The mainwheels are 2.5 inches, the current spring when fully wound is 1" diameter. I used 2" as my wound diameter, leaving myself plenty of expansion, since even with the shaft of the gears that run off the mainwheels (1st wheels?) there's plenty of room off the side in the box for expansion.

I'm putting the springs in tonight and running a test. My springs are 2-3 times longer than the originals, and only thicker since that's all TS had for a longer spring in that width.

It may fail miserably, it may not. Either way, it's a learning process for me.

Sorry if I'm a bit prickly at the moment, lots of drama elsewhere. :-(
 

Tinker Dwight

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Oct 11, 2010
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Hi
The open spring is less effective than the barreled
spring at using the most out of the wind.
Still, having more open space to unwind gives
you an advantage for the total unwind length
of turns.
Let me know how much that actual unwound diameter it
comes out to be and I can see if I can give you a better
number for the optimal number for the length to match.
Just don't get so pissed that you go for "suicide by police".
We just had a case of that in my area. It seems like people
are more concerned about the fellow not getting due
process than the people he killed.
Tinker Dwight
 

harold bain

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If you've ever worked on a Korean 31 day clock, you will notice how they get that runtime by forcing the spring to unwind away from the movement. Sure the spring is longer (170 inches), but it takes about 40 half turns of the key to wind them up.
 

Jay Fortner

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Feb 5, 2011
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If you've ever worked on a Korean 31 day clock, you will notice how they get that runtime by forcing the spring to unwind away from the movement. Sure the spring is longer (170 inches), but it takes about 40 half turns of the key to wind them up.
Yeah, I just did one of those today(japanese),geese what a spring. The lower legs of the movement have kickers(for lack of a better term) to kick the springs outward and they do work well.(don't ask me how I know)
You may try to fab one for your project.
Always wondered why they didn't run the coils from the inside out? I've seen clocks with their MS's wound that way and it always makes the springs uncoil outwards
 

mr_byte

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Nov 25, 2009
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Ok, so after a bit of delay, I installed the springs yesterday. These were the 96"x3/8"x.017 thick. It is a bit stronger than the originals; the strike is very fast and I may revert the strike to the original spring as it may actually run the strike for the needed 3 days.

After reassembly and oiling, I removed the verge, and let the time side freewheel (controlled by pressure on the escape wheel, so as to not break something due to the speed) and counted 6 revolutions of the hour hand, then installed the verge. Without a pendulum bob, but with the suspension in place, the movement was able to work the verge and so forth.

After this, I installed the movement back into it's case, and while it was laying on it's back and I was screwing in the movement, it sounded like a machine gun from the rapid rat-a-tat-tat sounds of the escapement.

So far I have allowed it to run 1 day with just the hour hand on (mostly as I was setting the beat and it's hard to do it with the dial in place) for rough tracking, and it seems to be keeping time decently. I've since reassembled completely, without rewinding, and am letting it run. So far, in the 4 hours it seems ok, maybe a minute gain, but that could also be play in the minute hand/shaft.

Unless problems in regulation develop, I'm calling this one a success, though the speed of the strike annoys me, however, I think it was nearly as fast before.
 

mr_byte

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Nov 25, 2009
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After more running, it seems that the time side is very fast. I may need to extend the suspension rod (pendulum rod?) to be able to regulate the clock down more, as the weight is down as far as it can go now, but it seems to be closer to keeping proper time.
 

Jay Fortner

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Feb 5, 2011
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Hey byte, I think you went the wrong way with your thickness,now your WAY overpowered. Here lately I've been installing thinner than original MS's and concentrating on burnishing and polishing EVERTHING. Even smoothing gear teeth,seems to be paying off. Go with the .015. If you have the ability,make a set of kickers like the 31 day clocks have on them so the coil will be forced outwards. You may wind up being able to put a lighter pend. bob on it and set the verge just deep enough so it has decent lock. I just messed around with a 1 day New Haven and got 3 days with the original springs by opimizing EVERYTHING.
 

shutterbug

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Heavy springs will wear out the movement faster, but I don't see them changing the timing that much. The time is basically controlled by the pendulum rate regardless of power.
 

leeinv66

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Heavy springs will wear out the movement faster, but I don't see them changing the timing that much. The time is basically controlled by the pendulum rate regardless of power.
That's not quite Shutterbug. The pendulum rate is not constant in a spring powered clock. That's why they invented fusees. To negate changes in pendulum rate during a winding cycle. I am into weight driven regulators and their regulation goes out the window if you change the mass of the driving weight.
 

shutterbug

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That's not quite Shutterbug. The pendulum rate is not constant in a spring powered clock. That's why they invented fusees. To negate changes in pendulum rate during a winding cycle. I am into weight driven regulators and their regulation goes out the window if you change the mass of the driving weight.
Yeah, I agree that they won't run consistently. But I'm doubting that a new spring would force the timing outside of adjustable range like this. I guess letting it run for the full wind will answer that question.
 

R. Croswell

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Ok, so after a bit of delay, I installed the springs yesterday. These were the 96"x3/8"x.017 thick. It is a bit stronger than the originals; the strike is very fast and I may revert the strike to the original spring as it may actually run the strike for the needed 3 days.

0.017 inch spring thickness is more than a bit stronger, it’s quite a bit stronger! That’s why the strike and time are both running too fast. You are really putting a hurting on the wheels and pinions that were not intended to take that much force. I have to agree with the others, you went the wrong way on the thickness. Generally, it’s the length that will add run time.

I have a Jerome 30-hour movement that I purchased on eBay as a replacement and when I got it I discovered that someone had stuffed in a thicker and wider spring than normal, presumably to extend run time. (You are by no means the first to try this). The main wheel teeth were all damaged beyond repair and the second wheel wasn’t much better. I had to just put it in the “junk box”. The rapid striking is your clock telling you that you are hurting me. It’s safe to do anything you want with the spring length as long as the spring thickness is no greater than the original. Thinner won’t hurt the clock (although at some point too thin a spring will not power the clock.)

I don’t recall if you said whether this clock has a count wheel or rack strike, but if is has a count wheel and you put less spring (length wise) on the strike side it will continually be getting “out of sequence” when the strike runs down first.

Jay is probably right about the recoil escapement. All else being equal, 30-hour clocks are better time keepers than 8-day clocks over the course of a week because they are wound every day. So they may run a little fast right after being wound and a little slow after 24 hours resulting in small ups and downs during the week, but the total departure from true time is often less than in an 8-day recoil clock.

This is all an interesting exercise in “clock physics” but I predict that if you are able to extend the run time to 3 days or beyond, the time keeping accuracy will likely suffer, especially if this clock has a recoil escapement.

RC
 

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Rockford's early high grade movements by Greg Frauenhoff