Overwound Watch?February 24 2007 at 11:38 AM
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from IP address 18.104.22.168
I've got a 1974 Timex with a 025 movement that I think is overwound. In theory (to me anyway) I would think that if the watch ticks for several seconds when you rock it back and forth that eventually it would unwind itself, I know that this could take hours or even days if my theory is correct. I have seen in an old Timex service manaul that showed how to release the mainspring in detailed photo's, two things though, I can't find them photo's again and I'm not sure that its the same for this year and model.
If anyone has a service manual for this year and model, and can take some photo's of that procedure that would be great, or maybe walk me through it step by step.
Re: Overwound Watch?No score for this post
|February 24 2007, 12:19 PM |
Mark, the mainspring being overwound is the most common misconception with watches and clocks. It is impossible to overwind a spring unless you wind it until it breaks and in that case yhe stem will just continue to turn forever. If the spring has been sitting for a very long time it can, however, take a set and will not release all of it's energy. What I find with most Timex's discribed as overwound is that they just need a good cleaning and lubrication.
If you feel you want to "let down" the mainspring the procedure is the same for all spring driven movements whether watch or clock. Simply locate the click spring that engages the rachet wheel and carefully release it. Never let it just fly as you could cause a lot of damage and wear. With your watch, simply grasp the stem and allow it to unwind slowly through your fingers. When you have let down the mainspring it is a good time to lubricate it.Care needs to be taken also not to let the rachet spin against the end of the click spring as some Timex versions just have a thin little point and if that wears you will have to replace the click. A common problem with these watches.
Hope this helps
About "overwound" watches...No score for this post
|February 24 2007, 4:06 PM |
I have to disagree with Bill D. I have serviced many watches that were, in fact, "overwound". This condition (never seen on an automatic watch) causes the pallet or pin lever's fork in a mechanical watch to be jammed to one side so that the balance wheel can not make it swing back to its other position. As you noted, such a watch will run a bit when it's case is manually twisted back and forth, but stops as soon as the watch case is motionless again.
The solution is to "let down" the mainspring by manually pushing the click tooth away from the winding gear on the barrel wheel while CAREFULLY holding the crown and allowing it to slowly turn between one's fingers.
Many Timex mechanical watches, however, do not have the click located so that it can be accessed from the opened back of the watch. On these, it is necessary to access the click from the front side of the movement's base plate by first removing the dial of the watch.
Generally, mainsprings in watches are pretty tough little pieces of metal and will only break after years of use or if they are severely rusted. It's always a good idea with a mechanical watch to only wind it up until the crown just begins to become tight. There is no need to wind it until it can not be wound another fraction of a turn. That extra fraction of a turn will only allow it to run a little bit longer and will put a lot of extra stress on the ends of mainspring that contact the winding staff and the inside surface of the barrel wheel. Such unnecessary stress will only shorten the lifespan of the mainspring.
P.S. ALWAYS lubricate the mainspring after cleaning the watch!
Re: About "overwound" watches...No score for this post
|February 24 2007, 5:53 PM |
Well I'll leave it up to the trained horologists on here to decide if the condition you describe is due to a "overwound" mainspring(which does not put DIRECT pressure on the escapement) or if in fact there is some other cause such as worn or bent pivots. I also do not understand how if the pallet is "jammed" that the watch will run when shaken unless you are saying the balance will move but the escape wheel will not. I would not consider that running myself.
My original statement regarding "overwound" mainsprings was information from a certified master watchmaker so if he is wrong I will inform him.
|Jack from Philadelphia|
I tend to agree with Bill D. (more)No score for this post
|February 24 2007, 7:09 PM |
that he describes the classic symptom commonly mislabeled "overwound." I know very little about watch mechanics but that is what I have read in technical manuals over the years. But it is also apparent that Technoguy has noted another problem that appears to mimic that symptom.
More about "overwound" mainsprings...No score for this post
|February 24 2007, 7:15 PM |
The escape wheel's rotation is controlled by the back and forth rocking motion of the pallet lever. This tiny lever actually momentarily locks the escape wheel at each of the possible maximum positions of the pallet lever. It is only the force applied to the fork at the end of the pallet lever by a pin on the rebounding balance wheel that supplies the tiny bit of torque needed to unlock pallet lever and allow it to then snap to its other maximum position. During this process the escape wheel is allowed to undergo a small amount of rotation and the entire gear train also moves a bit as do the watch's hands attached to the gear train.
The escape wheel, normally, has VERY low torque which is just less than the torque of the rebounding balance wheel that is supplied to the forked end of the pallet lever where it engages the pin on the balance wheel. However, on many mechanical watches, when the mainspring is "overwound", this action raises the torque of the escape wheel to a point where it EXCEEDS the torque that can be provided by the rebounding balance wheel. When this happens, the balance wheel will no longer be able to unlock the pallet lever so that the escape wheel can move. The watch, although apparently tightly wound, can not run. Its pallet lever is actually jammed at one of its extreme positions and held there by the excessive torque of the escape wheel.
Shaking the watch case of an overwound watch by rapidly twisting it back and forth momentarily adds some energy to the balance wheel and boosts the amount of torque it can then supply to the forked end of the pallet lever. Now, the pallet lever can rock back and forth again and the escape wheel will turn. The second hand of the watch will move as the gear train again continues to run. However, the movement will only run as long as the watch case is shaken. As soon as the case is no longer shaken, the balance wheel will, after perhaps a few oscillations, once again, no longer be able to unlock the pallet lever and one is back to having a non-running watch.
I have seen MANY watches with this condition and most of them did not require cleaning or lubrication. All they needed was to have the tension in their mainsprings relieved by "letting down" the mainspring.
If a watchmaker only services automatic watches, then he will never see this condition. Automatic watches have a special way of attaching the mainspring to the inside surfaces of their barrel wheels that allows the mainspring to slip in the event that the watch's automatic winding system starts to overwind the mainspring (which will happen if one uses a watch winder that is left on too long).
One of the nicest things about the quartz analog movement is that one never has to worry about this annoying possibility...only the annoying necessity of battery replacement.
Not to belabor the pointNo score for this post
|February 24 2007, 7:44 PM |
Here is what a quick google of overwound produced
10. Is my watch just overwound??? First, newer ever say your watch is just overwound. Unless you take a pair of pliars and force the watch to wind after it is fully wound and break the winding gears or the spring - then your watch is NOT overwound!!! If someone wants to sell you a watch and tells you that "It is just overwound!" - then either 1. - He doesn't know what he is talking about, or 2 - he is being dishonest and is handing you a line (hook, line, and sinker) to make you think the watch has little wrong with it. Watches stop for a reason. If you find a watch has stopped, the first thing you do is try to wind it. That usually works. However, suppose you drop your watch and break the staff. Then your watch will stop. You can then wind it back up, but it will not start running. It does not start because the staff is broke, not because it is overwound. You should have your watch serviced every couple of years if you want to carry it and use it. You certainly don't wait for your car to stop before you change the oil, DO YOU????
© Copyright 2001-2004 by Watchdoc - all rights reserved
Our repair department is headed by
shop owner, Claude Guyot.
A native of Switzerland, Claude
studied at Ecole D' horologie, Fleurier
He worked for a time at OlmaJeannin
and Fleurier Watch Co. before moving
to Bridgeport, Ct. to become manager
of the repair dept. at Waltham Watch
J. Byrne is a graduate of Manhattan
School of Music and Columbia U. He
has been with Swiss Time for 12 yrs.
Why has my mechanical watch stopped?
Certainly the number one reason is that
the oil in the watch mechanism has, over the
course of time, dried to a paste and begun to
cause too much resistance for the power of
the mainspring to overcome. This problem can
be made worse by infiltration of dust and the
inevitable weakening of the mainspring with
age. If a watch stops suddenly, then it most
likely was bumped and the tiny axle on which
the balance wheel spins has broken.
Forget about it
It just doesn't work that way. Watches
stop for the reasons shown elsewhere on
this page. They appear to be tightly wound
because the gears are not turning and the
mainspring remains at the same degree of
tension as when it was last wound.
Many times you will find watches being described as "overwound". But what does that really mean? Well, what it has become to mean that the watch is wound up all the way, but will not run.
Technically, you cannot overwind most wrist and pocket watches, modern or antique. They are supposed to be wound up all the way, until you cannot wind it up further with your fingertips. Most watches, when properly serviced, will run for 28 to 30 hours or more on a full wind.
The bottom line... when a watch is described as "overwound", it means that it has a problem causing it not to run. It could be routine maintenence, such as cleaning and oiling, or it could be more serious, like a broken jewel, pivot, balance staff, etc.
Bill you were right to start with if you...No score for this post
|February 24 2007, 9:15 PM |
wind it up as tight as it will go and that's all more than that would brake the spring or pull the spring out at the end, Strip a gear or the winding mechanism. I find if I wind a watch up tight and it won't run if I add some oil to as much of the moving parts as I can and roll the balance wheel with a tooth pick it will take off with only a few rolls works for me just about every time. I wind my watches up until they stop winding don't think I ever over wound one yet.
there is meritNo score for this post
|February 24 2007, 9:48 PM |
in technoguy's observations. Mainsprings are more or less isochronal when properly wound. However, the end of the mainspring that is attached to the barrel is generally 'doubled over' and much stiffer than the remainder of the spring and not intended for distortion. If the mainspring is forcefully wound to the point of leveraging the stiffer end away from the barrel, then conceivalby the dynamic of the spring's 'spring constant' may significantly change (relative to the disired) and deliver an undesired torque to the driven train. Cheaper watches watches generally use heavier mainsprings, so the result of forceful overwinding may be of even greater significance.
In theory, overwinding should be an impossibility but in the real world there are exceptions that prove the rule. I have read similar debates and often watchmakers are insulted by the term but I suggest that if the impossible is easily dismissed then future advances may arrive begrudgingly.
Just my 2 pesos
Certain watches are more prone to overwinding...No score for this post
|February 24 2007, 11:23 PM |
I do agree that there are many reasons for a watch to stop running and, of course, many of them do need cleaning and lubrication. A gear train that is loaded up with rancid oil and metallic grit will have a lot of drag in it and that, by itself, could stall the gear train out even if the mainspring was fully wound.
However, I have PERSONALLY serviced MANY watches that were NEW with fresh oil and gears and they were, indeed, "overwound". When their mainsprings were "let down", they all resumed normal running. I know for a fact that this is a REAL problem that can exist in a mechanical watch.
I've also noted that many of the watches with this problem were ones that tended to have oversized crowns on them that were deeply ridged. Such a crown gives the wearer's fingers a good tight grip on the crown during winding and a sort of enhanced mechanical advantage that encourages forcing the watch's mainspring to be excessively wound or, actually, "overwound".
I think a lot of watch manufacturer's are aware of this potential problem and purposely make their watches' crowns smaller and smoother so that it is more difficult for the wearer to get a tight grip on them. In any event, I always advise those wearing mechanical watches that require winding to take it easy when doing so. The crown does not have to be so tight that it can not even be turned another 1/8th of a turn. That's way too tight!
Must be using the wrong size mainspring. (nt)No score for this post
|February 24 2007, 11:35 PM |
Something to tryNo score for this post
|February 24 2007, 8:48 PM |
First, I am glad to see a technical discussion. Of course, many technical discussions occur on the forum but this paticular topic demonstrates a real world debate and I am glad that cool are the heads that contribute. Overwinding may or may not be possible -physical equations can prove or disprove the possibilty- and I personally have no problem with the correct or incorrect use of the term.
Concerning your watch:
1 Given the age and that it is a Timex, it probably needs servicing. The oil
may be dirty or oxidized and impedeing the train.
2 It could very well have a bad pivot and the gears are binding
3 The mainspring may have a tacky residue which causes binding when fully
4 bad hairspring with touching coils
All possible senarios point toward a good servicing. I have temporarily repaired overwound watches by letting down the mainspring and rewind as recommended by technoguy. A pretty good test for your situation is to remove the movement, detach the hands and dial, and place the movement in Naptha. Usually, not always, if the movement train is in good repair and only dirty then it will begin to run while in the solution. So, a good cleaning is in order. Naptha can produce surprising results if the movement is allowed to spin slowly in the solution for a good while. Hope this has been of help.
It is not possible to overwind a watch...beat error....No score for this post
|February 24 2007, 10:58 PM |
It is best to fully wind a watch until the crown will not turn any more in the clockwise direction, once each day, at about the same time each morning. An iso-chrono watch will keep equal-time when the mainspring is at a full wind or when wound down.
Technoguy seemed like he was describing the beat of a watch. When out-of-beat, the pallet fork will favor one side of the banking pins or bridge.; traveling more on one side of the staight line between the balance and escape wheel jewels. A watch that is too far out-of-beat will not run unless shaken with a side-to-side motion.
When a watch is in beat, the impulse faces of a pallet stone/jewel or pin (non-jeweled) will rest on an escapement wheel tooth. When the watch is wound, the force from the mainspring is transfered through the gear train, causing an escape wheel tooth to push on the pallet stone/jewel, imparting motion to the pallet fork, which imparts motion to the balance wheel causing the watch to run.
I agree with JayNo score for this post
|February 25 2007, 12:42 AM |
Some folks just call a watch that is wound tight overwound. To me that just means it needs service, probably a cleaning.
The mainspring should never be the problem (only if the mainspring was rusted or stuck together and wouldn't send power to the rest of the watch).
As soon as TG described the situation of letting the mainspring out to correct the problem I thought "over-banking". Yes, the mainspring is fully wound, but the problem is with another part of the watch... i.e. palet jewels not lining up right on the escape wheel or a roller jewel not banking properly.
Anyway Mark, we didn't want to scare you away.. so before you say "I'm sorry I asked", I'll go back to Bill's original comments that the watch needs service.
Colin gave you some good suggestions of what to look for.
Another "symptom" of being "overwound"...No score for this post
|February 25 2007, 2:05 AM |
Aside from locking up the gear train, many of the overwound watches I've worked on could not have their mainsprings "let down" by simple pushing the click's tooth away from the rachet gear with a jeweler's screwdriver. The mainspring was so tightly wound that it was actually necessary to physically REMOVE the click and its spring in order to let down the mainspring!
For some odd reason, people believe that a mechanical watch is not "fully" wound unless it is impossible to turn the crown anymore.
Sadly, when the owner of such a watch brings it to a watchmaker unfamiliar with the problem for "repair", he can be talked into getting an unnecessary new mainspring, cleaning, lubrication, etc. when, in reality, the problem could actually be corrected in a matter of minutes by the watchmaker with the push of a jeweler's screwdriver.
A solutionNo score for this post
|February 25 2007, 7:34 AM |
Techno,have you personally ever been able to overwind a watch? You are a theorist and I tend to be realist so here's an offer. I will send you a few NOS Timex movements and you can use them to try and "overwind" them. If you can do that then I will be happy to kneel at your feet
and concede you were right and the rest of the horologists of the world were wrong. (at the very least you wind up with NOS movements you can sell on ebay whether as running or "overwound".)
This morning to conduct my own real life experiment, I just took an old #22 movement from a 50's sample watch, that has not had sevice (They have the old larger crown you mentioned). I wound the spring as tight as I could without using pliers and the movement is running! I also did the same with a 1969 #24 that was unserviced. That one I even used a winding tool until it just slipped on the stem! MY theory is that all those watches that you "serviced" by letting down the mainspring had other underlying problems. Why would you not service the watch at that point?
My email address is in the header
Thanks for the offer...No score for this post
|February 25 2007, 8:25 AM |
but I would not want to take movements that you could be using for your own restoration projects. It's true that, nowadays, I am nore of a "theorist" than an active watchmaker. I only occasionally service a timepiece for a friend as a favor. However, I was VERY active in amateur watchmaking during the '60's and '70's and probably saw every possible problem that a clock or wristwatch could develop and saw them on a wide variety of watch brands.
I can only restate that, in my most "active" period of watchmaking, I saw a wide variety of relatively new watches that had been brought to me by people who, themselves, told me that they had inadvertently "overwound" their watches and wanted me to correct the problem. Practically all of these watches resumed normal running AFTER their mainsprings had been "let down" and most did NOT require either cleaning or lubrication.
I remember several watches with this problem that I first examined to see if, somehow, the impulse pin on the balance wheel had slipped out of the fork at the end of the pallet lever which had then allowed the lever to jam up against one of its overbanking pins. But, this was NOT the problem. The parts were properly aligned and, by carefully manually rotating the balance wheel in the proper direction (using the tip of a toothpick), I was able to unlock the pallet lever so that it would then flip over to its other position and, in the process, give the balance wheel a bit of a kick. When the balance wheel then began to oscillate, however, its rebound would not be sufficient for it to again return the forked end of pallet lever to its starting position. Since the watch had NO other mechanical problems, the ONLY conclusion I could reach from this was that the escape wheel was being supplied with TOO MUCH torque and that this was the cause of the problem. Nearly ALL of these watches ran normally AFTER their mainsprings had been let down.
Surprisingly, when one looks for a description of this condition on the internet, there is no mention of it although one can find many sites that sell mechanical watches and caution the buyer not to overwind the timepiece. I guess that just goes to demonstrate that everything important in watchmaking is NOT necessarily on the internet! I trust to my experiences when describing this problem.
You say that you have been unable to recreate the problem with your NOS movements. Well, not all watch movements may be prone to this potential problem. It probably depends upon the design of the movement's escapement, particularly the leverage that exists when the rebounding balance wheel's impulse pin engages the forked end of the pallet lever.
While I am fairly certain that I saw this problem on several Timex watches from the '50's and '60's, I am 100% certain that I saw it on a variety of supposedly better Swiss watches and on many of the low cost mechanical watches being imported from the Orient at the time.
Re: Overwound Watch?No score for this post
|February 25 2007, 9:35 AM |
I think this turned in to an excellent discusion. I hope I did'nt cause any hard feelings here! Several things now though, after reading all these posts I should have been a little more specific in my original post. First, after rocking this watch lightly back and forth it will run for 15-20 up to 25 or 30 seconds, also, this watch is not wound so tight that you can't wind any more, so I guess after all this it sounds more like my watch is just dirty.
So now maybe I should start a new post? So now maybe some suggestions about how to clean a movement without an ultrasonic cleaner? Someone mentioned Naptha but I'm not sure what all needs to be removed from the movement before you start?
Thanks all; Mark
No hard feelings hereNo score for this post
|February 25 2007, 10:19 AM |
Mark, Techno and I have disagreed in the past (and most likely will again in the future) but that does not mean I don't respect him and what he brings to this forum. As I said we sometimes look at things differently but to me thats a good thing. who wants to march in lock step? He certainly has more years of experience working on watches than I.
As for the cleaning methods, I would suggest a new thread. This one has run it's course and you wil get plenty of different thoughts on a cleaning thread. keep in mind what will be suggested is what works for that individual so try them and find what works best for you.
Keep posting and stirring the pot!
This is merely an exchange of opinions...No score for this post
|February 25 2007, 11:59 AM |
which are based on each of our relatively unique experiences with amateur watchmaking. Whenever an issue is debated here, it's a good idea to follow the differing opinions and then keep them in mind as one pursues the hobby.
I think that many unusual problems that watches develop can be likened to, say, the issue of the existence of UFOs. IF one has seen a UFO, then it is easier to accept their reality than if one has not seen one and, in similar fashion, if one has encountered a particular unusual mechanical or electrical problem in a timepiece, then it is also easier to accept it as a possibility.
Only a small percentage of the watches I've ever worked on were "overwound" according to the way I have defined the problem above. Most either needed only a simple cleaning and lubrication or had suffered a critical failure due to a broken part. Routine movement cleaning, lubing, and regulation are easy enough procedures to accomplish. However, trying to repair a broken part or find a suitable replacement for it can be a LOT more challenging.
Overall, I've only had about a 70% to 80% success rate in fixing watches for friends, but they usually came to me out of desperation because their local watchmaker either did not want the repair job (a typical reaction when handing a professional watchmaker a Timex in need of repair!) or, if he would accept the job, wanted too much for it. I rarely charged anybody for a repair and always found great satisfaction in being able to help my fellow human beings with a problem which, to them, seemed insurmountable.
P.S. Just to dispel any false impressions that might be created by the "techno-" part of my username, I do NOT have all of the answers when it comes to the art and science of watchmaking. Like everyone else here, I'm still learning.