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jdm

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  1. Like
    jdm got a reaction from lumentin in My first repair : Seiko 7S26C Oscillating Weight Failure   
    Yes, remove the rotor and soak it in alcohol.
  2. Like
    jdm reacted to JohnR725 in Chinese Timegraphers   
    taking it on and off would add a new variation of having to wait at least 30 seconds for the watch to stabilize otherwise that's going to introduce a variation. the timing machine has a start/stop button. Each time the button is pushed it cycles between stopping which is freezing the display then starting a timing cycle starts over from the very beginning no need to remove the watch.
    that's an interesting observation which implies we would have to compare it to something? when the Chinese 1000 machines came out one of their selling points was the screen there were very proud of their backlit screen. At that time there comparisons were with the witschi watch expert II as it does not have a backlit screen. if we use their comparison then you're right the Swiss machine does have a nicer microphone considerably more more analog processing circuitry enhanced features plus a minor price difference.  okay perhaps it's not a minor price difference comparing a professional Swiss machine that  is just under $3000 to a Chinese machine that's under $200 is an interesting comparison isn't it?
    then how does the Chinese  timing machines compared to the Swiss? I've already done that experiment couple years ago. I compared the witschi watch expert 2 with the Chinese 1000 and 1900.. for the most part they are very very close so close that I have no problems recommending either Chinese machine.. although I like the display better on the 1900 machine..
    being curious about the start and stop problem I decided to try an experiment.. The benefit of collecting timing machines..  The witschi watch expert two  and the Chinese 1000 machine.. Basically the 1000 analog and programming for the most part is identical to the 1900 at least close enough. The watch that I was timing is a Hamilton 992B pocket watch. Mainly because it was convenient and it's a lot easier to have two microphones attached to a pocket watch..
    basically the exact same set up I had before just a different watch. but there seems be a problem with the 1000 machine not correct technical term but it's not happy?  The LED is flickering  but not in nice rhythmic way.  the machine is having a problem figuring out  the beats per hour it's just taking a long time. Once it figured out the beats per hour the rate was fine but the amplitude took almost a minute and was wrong.. basically the machine is not getting a good clean signal?
    this is a  problem more common with wristwatches in their case.. A lot of times of the case is big heavy cases sometimes the movement is plastic a variety of things can cause the signal not to get out.. This is where the recommendation is rotate the watch until the crown  is pressing against the part of the microphone where the sensor is located.. This should give you the best signal.. repositioning the pocket watch and the microphone the LEDs looking better everything is looking nice now. The witschi microphone is now clip to the side of the watch case it is working just fine. So there appears to be some minor signal problem with the pocket watch that the 1000 as having issues with the witschi is not. This is where in our oscilloscope feature is really nice missing from both of these machines.
    now that both machines are simultaneously appearing to work let's look at the numbers and see the difference between them. The witschi indicates +2 seconds 226° 0.5 ms. The Chinese 1000 is +1 225° 0.5 ms so other than the initial microphone issue which I still think it's odd both machines are basically tracking very very close to each other.
    I do curiosity I thought I would do a test where did I turn the machine off turn it back on and it's roughly 25 seconds to reestablish all the numbers then looking at the witschi machine it looks like everything is real close the amplitude is off by 5°. Some of this I think is because on power up it defaults to an averaging where sample time of four seconds and that's going to change things a little bit.
    now for the final insanity part? Were not exactly comparing the same thing in that the witschi is averaging over 20 seconds updating every two seconds. Watching the display I noticing a amplitude variation anywhere between 229 up to 240 something this is a very slow variation over several minutes and it's not exactly rhythmic or consistent. as a guess this is what happens when you have several variations in issues seeing as how I know the watch hasn't been serviced in a while.
    So with the Chinese machine I push the stop button right the numbers down the rates are very very consistent the same as the witschi machine so I'm going to ignore the rate for this test only look at the amplitude because that's the only thing that's showing any variation. So what I push the stop button I write down the number wait a moment push the start button once stabilizes right that number down this is why made a reference to insanity. Of and as a reminder the 1000 machine is set default sample time before seconds and we have no idea how the machine actually averages it would definitely be more stable if I would adjusted 20 seconds but the person who originally posted this never change the setting so I'll keep it where the machine would be for him.
    So stopped 237° it starts up at 225° compared to the witschi at 237°. Then running the test again 225° starts up at 236 and the witschi's 237.
    so the basic conclusion of all of this is the Chinese machines are relatively stable the microphone isn't quite as nice as the witschi the amplifier and so forth aren't quite as nice but it still doesn't really impressive job. For the original person posting we need more information? Like if you stare at the timing machine do the numbers change at all over several minutes? Are you seeing a slow variation. Because if there is a variation and you stop and start the machine up you going to see that where you had a number and it's going to jump to the variation number. If the graphical display is not a nice smooth line like mine is you're going to see a variation in the rate. Then if you change the sampling time to 20 seconds it will help to smooth things out.
     
  3. Like
    jdm reacted to JohnR725 in Chinese Timegraphers   
    I'm not sure if the phrase slightly worse is appropriate. Several years ago when I was in a teaching situation of teaching hobbyists watch repair. One of the students loaned me his small collection of pocket watches and his Chinese 1000 machine because he was concerned about the results he was seeing.  this made for a really nice lecture with pictures. Then much later on one of the other students loan me his 1900 machine to do a comparison with.
    now of course I acquired a 1000 machine on eBay used for hundred dollars. You can never have enough timing machines.
    before we continue I turned both timing machines back on then I was doing something with the witschi you can't do with the Chinese listening to the ticking sound as I was still bothered by the issue of yesterday. Then I wrote down the numbers. Witschi thinks the watch is +3 seconds fast 222° 0.5 ms beat the 1000 machine thinks the watch is +3 seconds fast 226° and 0.5 ms beat.
    I'm not sure if it's going to answer your question or not but I have a link to the second page of this discussion it will probably give you some answers and bring up new questions
    then when you make comparisons between the differing machines other issues can come. Like what's the consequence of having a small graphical display like the 1000's? Or the Chinese machines typically do not display error messages they will always try to give numbers what's the consequence of that?
    The problem with a small graphical display is and we've done experiments on this group somebody had a watch that was perfectly in beat graphically but numerically the number did not agree? This is where on in a timing machine if the numbers do not agree with graphical results you have a problem. so what happened is the watches perfectly and beat graphically but numerically it was a huge number? This is because on the small display when you reach the edge to display it basically rolls over to the top and then you start getting goofy results. See you might have a watch that looks perfect but it's really not.
    Then my reference to always giving numbers? I have a saying which is garbage in garbage out relating to timing machines. If the graphical display seems to be random dots and you have nice numbers the numbers are wrong. this is one of the reasons I always ask for pictures of graphical displays because you can see things there that you can't see numerically.
    https://www.watchrepairtalk.com/topic/4124-chinese-timegraphers/page/2/
  4. Like
    jdm reacted to nickelsilver in 3 jaw chuck   
    I don't recall running across an independent 4 jaw chuck for a watchmaker's lathe yet, though I know they exist. I do use a 4 jaw on my larger (102mm center height) lathe quite often.
  5. Like
    jdm got a reaction from Weetabix in Seiko 7009-3170 crystal, gaskets?   
    Among others, Cousins UK and Boley.de let you search by case reference for Seiko and other makers.
    Very good, BTW I have broken my good share of crystals and other assorted parts too.
    Yes. That allows to delivery fine contours and details with ease of manufacturing.
    Below 1.2mm they break very easily, you can break a 0.8mm pushing it out by hand. Try to use only crown type dies on the crystal, and a lever type press if possible, as it provides better feedback. 
  6. Like
    jdm got a reaction from Weetabix in Seiko 7009-3170 crystal, gaskets?   
    No, as mentioned above it's never so on that class of watches. And gaskets can always be re-used unless damaged messing with them as happened here. I'm afraid the OP is a bit ham fisted, working on crystals is delicate - just as everything else on watches.
  7. Like
    jdm got a reaction from meanoldmanning in Seiko service repair   
    The answer "yes" given above is substantially correct but incomplete and hurried. 
    For example, on the very popular swapping to a SKX 200m divers, one cannot reuse the original stem/crown combo, so a new one must be bought.
    Then, one must reuse the original movement ring, as well the day disc.
    But you cannot count on carrying over the date wheel, because that changes across versions. 
    I wrote about that many times here and on WUS, it should be easy to locate my postings for those that desire to gain full understanding and do a perfect job. 
  8. Like
    jdm got a reaction from vinn3 in 3 jaw chuck   
    Not just the build quality, but the intrinsic limits of geometry and tolerances. Since the driving element a spiral groove that is common to all jaws, which must also work reversed, some design compromise must be taken so keep it acceptably smooth.
    For example, on my Unimat 3 copy I have less than 0.01mm runout at the spindle chuck spindle register, but about 0.12mm with a precision 7mm round bar in the 3 jaws - which is the same as the Ebay example above.
    There are ways to improve concentricity on  self-centering chucks, but in the end if precisions is needed either use collets, independant jaws, or turn between centers. There can be more ways also, as machining is full of ingenious methods.
    All that being said, here we are talking about hobbyist / non-precisions chucks only. I'm sure that watchmaker's and and professional machines chucks have a different precision class. 
    Not all 4 jaws chucks are of the independant type, and not all sellers do specify. Look for square sockets on the body in line with the center of all jaws. Below an self-centering 4 jaws chuck, again for the Unimat 3. These are mostly used for woodwork where high precision is not important, but you need to grab square section parts often. 
  9. Like
    jdm got a reaction from JohnR725 in Seiko 7009-3170 crystal, gaskets?   
    Not on these Seiko five which are built for simplification and ease of assembly. Just press out and replace with a generic crystal. No point in wasting time chasing original parts that even if found would cost more and be identical. 
  10. Like
    jdm got a reaction from watchweasol in John from East Coast U.S. and eBay 7s26A (genuine movement?)   
    That is absolutely normal, Seiko has produce this movement over many decades and in various factories in Asia, variations in finishing and lettering are expected. 
    The advice to replace with a brand new NH36 was also a good one, then of course anyone does as he pleases. 
  11. Like
    jdm got a reaction from watchweasol in Seiko 7009-3170 crystal, gaskets?   
    Not on these Seiko five which are built for simplification and ease of assembly. Just press out and replace with a generic crystal. No point in wasting time chasing original parts that even if found would cost more and be identical. 
  12. Like
    jdm got a reaction from watchweasol in Tissot pr516gl overhaul   
    The scuff marks on the crystal can be easily polished, or a generic flat one be fitted. 
    You can desume the hands hole size from the movement used and get generic baton one. Again, it seems to me that all original ones need is a bit of cleanup. 
  13. Like
    jdm got a reaction from mikepilk in Seiko service repair   
    The answer "yes" given above is substantially correct but incomplete and hurried. 
    For example, on the very popular swapping to a SKX 200m divers, one cannot reuse the original stem/crown combo, so a new one must be bought.
    Then, one must reuse the original movement ring, as well the day disc.
    But you cannot count on carrying over the date wheel, because that changes across versions. 
    I wrote about that many times here and on WUS, it should be easy to locate my postings for those that desire to gain full understanding and do a perfect job. 
  14. Like
    jdm got a reaction from Weetabix in Seiko 7009-3170 crystal, gaskets?   
    Not on these Seiko five which are built for simplification and ease of assembly. Just press out and replace with a generic crystal. No point in wasting time chasing original parts that even if found would cost more and be identical. 
  15. Like
    jdm reacted to Narcissus in Lapping setup   
    My exact listing is gone but the parts are:

    - Celestron Astromaster CG-3
    - CME 2”/50mm 3 jaw Chuck
  16. Thanks
    jdm got a reaction from Klassiker in 3 jaw chuck   
    Not just the build quality, but the intrinsic limits of geometry and tolerances. Since the driving element a spiral groove that is common to all jaws, which must also work reversed, some design compromise must be taken so keep it acceptably smooth.
    For example, on my Unimat 3 copy I have less than 0.01mm runout at the spindle chuck spindle register, but about 0.12mm with a precision 7mm round bar in the 3 jaws - which is the same as the Ebay example above.
    There are ways to improve concentricity on  self-centering chucks, but in the end if precisions is needed either use collets, independant jaws, or turn between centers. There can be more ways also, as machining is full of ingenious methods.
    All that being said, here we are talking about hobbyist / non-precisions chucks only. I'm sure that watchmaker's and and professional machines chucks have a different precision class. 
    Not all 4 jaws chucks are of the independant type, and not all sellers do specify. Look for square sockets on the body in line with the center of all jaws. Below an self-centering 4 jaws chuck, again for the Unimat 3. These are mostly used for woodwork where high precision is not important, but you need to grab square section parts often. 
  17. Like
    jdm got a reaction from jdrichard in Can extraction gassoline disolve shelac?   
    That is just a less refined "petroleum ether" above. Leave a drop evaporate on a clean glass, if it leaves no residue then it will be fine.
  18. Like
    jdm got a reaction from vinn3 in Can extraction gassoline disolve shelac?   
    We have had this discussion so many times but it still happens every time the word is mentioned. You are referring to benzene, that is  a common mistake for English speakers. 
    https://en.wikipedia.org/wiki/Benzene
    Not to be confused with Benzine.
  19. Like
    jdm got a reaction from jdrichard in Can extraction gassoline disolve shelac?   
    We have had this discussion so many times but it still happens every time the word is mentioned. You are referring to benzene, that is  a common mistake for English speakers. 
    https://en.wikipedia.org/wiki/Benzene
    Not to be confused with Benzine.
  20. Thanks
    jdm got a reaction from watchweasol in 3 jaw chuck   
    These are Chinese chucks as made by Fuerda, Sanou and others. Normally fitted to the Unimat 3 and copies. OK for general use but not applicable to precision or watchmaking work.
  21. Like
    jdm got a reaction from vinn3 in New bench   
    Looks nice but still low for the ideal working position. Either sit lower or make a "riser table" with a matching material. I have used that during a workshop in Switzerland and really liked the idea.
  22. Like
    jdm got a reaction from vinn3 in Can extraction gassoline disolve shelac?   
    There is a better choice than gasoline, or lighter fluid, as neither of these are horological products, are not recommended by any manufacture. That is "petroleum ether", it may have different names in different countires, and is available online, at pharmacies, or chemicals shops. please check wikipedia or search this forum to learn more about it.
  23. Like
    jdm got a reaction from JohnR725 in New bench   
    Looks nice but still low for the ideal working position. Either sit lower or make a "riser table" with a matching material. I have used that during a workshop in Switzerland and really liked the idea.
  24. Like
    jdm reacted to HSL in Screwdriver Tip Repair   
    The first blade is for sure not shapened with a hollow shape, but it has a to hardened tip with brittle metal, one can se it flaking away which isn't good.
    In my book to get a really nice surface one can use both of these sharpeners with the horotech style one just must get it to fit good in the toolholder.
    Swisstech makes a similar one with a bunch of inserts so you always will get the perfect result, and fast, but always with quality the price is a downside. 
    A screwdriver with a softer tip, like the one below made of berylium is almost impossible to get perfect without a good sharpening tool.


    And in the end it's like with racing with cars, a good car will take you a long way but it's the man behind the screwdriver that makes the difference
  25. Confused
    jdm got a reaction from Nucejoe in Oil the pallet fork pivots of seiko 7s26/7009?   
    I am not sure what are you talking about. Japanese never bought largely in the Swiss industry. Just recently some Chinese and other Asians bought dead brands, and one smaller Swiss movt manufacture. If you want to learn how things are evolving have a read to the below and other articles from the same magazine
    https://www.europastar.com/watch-knowledge/1004087450-mechanical-who-will-succeed-eta.html
    Again I am afraid that you have ignorance fueling prejudice. Seiko makes large SS watches because that's what the market demands, last time I checked that is the same other brands are also making. Then if you care about learning one thing or three about Japanese manufacture I suggest that you have a read about past and present Grand Seiko offering, and the long gone time when they were giving the Swiss an hard time at the Chronograph competition using a flat hairspring, before the nice hosts of the venue changed the rules to avoid further loss of face.
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