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If a watch looses in Dial Up and Dial Down (Horizontal) positions, but gains in the Vertical (Pendant up, etc). Would this tend to indicate either to much endshake and/or sideshake? Mike Miller NAWCC Member# 154831 NAWCC-IHC Charter Member# 27 | |||
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Doug, This particular one has me stumped. The balance is in poise and the timing through all vertical positions is constant. The fact that it looses in horizontal positions is what has me confused. The friction between the jewels and balance pivots in the horizontal positions should be at their theoretical least. Both upper and lower jewels are fine, balance pivots are in good shape, there is endshape and sideshake. But how much is to much and would this be a likely cause? I am new enough in this that I haven't seen this particular problem nor does any of the literature I have describe causes and solutions. I have had watches that gain in horizontal and loose in verticle positions because of worn or burred pivots, and a lot of the liteature discusses causes for this delima and its solutions. I supose that I could restaff the watch and find out if the problem was caused by pivot shape, But I thought I'd run it up the flagpole to see what others thought. Maybe I'll try and post a picture of the pivots and see what folks think. Mike Miller NAWCC Member# 154831 NAWCC-IHC Charter Member# 27 | ||||
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Here's a link to pictures of the pivots in question... Upper Pivot Lower Pivot Mike Miller NAWCC Member# 154831 NAWCC-IHC Charter Member# 27 | ||||
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IHC Life Member |
Mike, I agree with Doug. I just have a couple of things to add: Do you have a baseline to start from? Was the watch taken down, cleaned, lubricated, balance trued in the flat and round plus poising? It's sometimes hard to diagnose a problem unless you have some sort of baseline to start with. If the watch was cleaned and lubed, was the balance jewels removed for cleaning? If so, were you able to get plenty of oil via capillary action into the cap/pivot jewel assembly? Sometimes I have to stick a very fine probe into the pivot jewel to get the jewels to take enough oil in so it will have its own little supply reservoir. Those are great close-up pictures of the staff. They are so good, I can see what appears to be corrosion and dirt. John D. Duvall Rosamond, CA. NAWCC Member 144772 NAWCC IHC Member 192 | |||
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John, You have brought up great points. I'll relate how I addressed them. quote: The baseline is that it was a watch that didn't keep particularly good time (for it's previous owner), even though it is a high grade Illinois. quote: Yes the watch was taken down completely and cleaned (mechanical cleaner with comercial cleaner and rinse). Balance was trued in the round with truing calipers and poised on a poising tool (Levin with Ruby Jaws) quote: All balance jewels (along with other cap jewels) were taken out and individually cleaned. All hole jewels were pegged. quote: Proper ammount of oil was applied to the hole jewels with caps prior to reassembly (3/4 of surface area under caps show oil resivoir). quote: You sayin i posted dirty pictures . There is some corosion on the top of the balance visible where the hairspring collet has been removed (folks should not leave these on when cleaned IMO). The other thing you will notice is that the balance appears rough, as in not finely polished in the areas of the shoulders. Also remember that this shot was taken at 40 power magnification, so every wart will show. BTW, this is a different watch than the one I had mentioned in a previous post about taking weight off of the balance. Thanks to your help, it is now running perfectly and keeping time in positions with the regulator right in the middle just as it should be... So thanks for the help on that one. So this one continues to puzzle me. It continually and very consistently looses 40 seconds per 24 hours in the Horizontal Positions (Dial Up and Dial Down). Timing in the Verticle Positions (PU, PR, PL, PD) will cause it to gain 30 seconds per 24 hours in each of these trials. This watch was originally adjusted to 6 positions. Perhaps I'm being very anal about this watch, but I find it quite an enjoyable challenge. Keeps me out of the corner saloon, at least for now Mike Miller NAWCC Member# 154831 NAWCC-IHC Charter Member# 27 | ||||
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IHC Life Member |
Mike, I'm happy you got you're other watch keeping time. I took the liberty of brightening up your staff photos: http://www.qnet.com/~jdduvall/mikestaff.jpg There does seem to be corrosion on the staff shoulders. That could very well be your problem. Do you have the tools to polish them? If you can give me the watch particulars such as size, jewels, and staff part number, I will see if I can find the dimensions for you so you can measure the overall staff length and the width of the pivots to see if there is any excessive wear. Not long ago I purchased a digital caliper on Ebay for about $22.00. It's not top of the line but works great. You can convert mm's to inches or vice versa on the fly John D. Duvall Rosamond, CA. NAWCC Member 144772 NAWCC IHC Member 19 [This message was edited by John D. Duvall on February 03, 2003 at 2:20.] | |||
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<Doug Sinclair> |
Mike, The very tip of each pivot should be rounded, so that there is only "point" contact by the pivot on the surface of the cap jewel in the face up and face down position. It is possible, if a watch is dropped face up or face down, to FLATTEN the tip of the pivot. In extreme cases you can end up with the tip of the pivot actually rivetted so it won't come through the hole jewel as well. You could also break a cap jewel. But in the condition described above, the jewel isn't broken, and the pivot is not rivetted, just flattened. Now you have lost the "point" contact on the one pivot. I would offer that the time rate shouldn't vary tremndously if this condition exists, but it is likely to make a noticeable difference in the rate. By the way, how much of a difference between the face up and face down rates are you getting? Doug S. | ||
Watch Repair Expert |
Timekeeping in the vertical positions that's consistent, but different from that in the horizontals, is almost certainly indicative of an isochronal error. The reason is that in ALL watches, balances will take more motion in the horizontal positions than the vertical ones (typically about 35 degrees more). End shake is relatively inconsequential, except in certain wristwatches, which have staffs with specially designed pivots. Poise errors will cause widely varying rates in the various vertical positions. Assuming the mainspring is in good condition, isochronal adjustment is accomplished by altering the overcoil on watches with Breguet type hairsprings, or by altering the spacing between the regulator pins on watches with flat hairsprings. In some situations, it may not be possible to completely eliminate all errors without extensive modifications (i.e. different size balance jewels and staff, etc.), but for a high grade Illinois, it should be possible to eliminate the errors to about 10 sec/day or less. Positional adjusting is one of the most challenging aspects of watch work, and in many cases, it's as much "art" as science. There are volumes written on the subject, and I've written "volumes" myself about it on the old "green board." If you have specific questions, please don't hesitate to inquire additionally! Steve Maddox President, NAWCC Chapter #62 North Little Rock, Arkansas | |||
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Been at this one for a while. And the verdict is in... Steve nailed it! Congrats to Mr Maddox. Shortening the arc of the overcoil brought the horizontal and vertical positional timing in tune. I'm now the happy owner of a Bunn Special that keeps excellent time. Thanks to all who have offered advice on this one. Mike Miller NAWCC Member# 154831 NAWCC-IHC Charter Member# 27 | ||||
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