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About Doninvt

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  • Location
    Vermont, USA
  • Interests
    Outdoor activities like biking, kayaking, photography. Fixing things like bikes, kayaks,, cameras.
  1. If a scratch is deep, you might be better filling it with something with a similar index of refraction rather than taking down the whole surface. Maybe that stuff they use for filling chips in windshields.
  2. For completeness, here is the result after putting the watch in the refrigerator (37F) for half an hour. Only a small fraction of the sec/day/deg difference that the warm (89F) gave compared to 65F ambient. I also note that my 7s36 based watch has just a very few seconds difference between 65 and 89 deg F. I'm thinking maybe there's an irregularity in the hair spring that goes critical (touching an adjacent turn of the coil?) at a particular temperature.
  3. On one of Marc's videos, he found this had been done at the factory on a new movement (chinese?)
  4. A priest, a doctor, and an engineer went golfing. They were frustrated by the extremely slow pace of the group in front of them. When they complained, the manager said, "Those guys are firemen. A few years ago we had a fire and they saved our clubhouse. Unfortunately, those 4 were blinded in the fire. In gratitude, we granted them free golfing for life." The threesome immediately went quiet and thoughtful. Then the priest said, "I'll certainly say a prayer for them tonight." The doctor said, "A friend of mine is a top eye surgeon. Maybe he can do something to help." The engineer said, "Why don't they play at night?"
  5. It seems to be the temperature of the watch returning to ambient. The rate difference is observable both fully wound and a day into the reserve. For the graphs I posted, the ambient was about 10 minutes after winding, then 20 minutes in the oven to stabilize at 89F before that graph was taken. I can try winding a few clicks to see if there's a difference
  6. Yes, purchased new and recently. As it came, I'd say more made to stay sitting on a table, since that's where it keeps good time if I keep it manually wound. (That may change as we move into summer and the ambient temperature goes up 10 or 15 degrees C) In the ways I can observe through timegrapher, this 6r15 seems to do better than my Seiko 5 (7s36) in things that can be attributed to care in assembly or materials: Position variation, beat error, regularity of beat, time to recover from changed position. Yet, the 7s36 shows nowhere near that temperature dependence. As an engineer, I'm wondering what the cause is, maybe spring stiffness changes with that Spron alloy? I haven't heard of this being a general thing with 6r15's (D version if that matters). Being well out of Seiko's specification, is there any recourse through the dealer, given that it's a Japanese Domestic Market model and I'm in the US? If not, any other solution (maybe a new balance?) I could regulate it "for the wrist", but if the basic T dependence is there, there would still be seasonal variation that I don't see on my cheaper Seiko.
  7. On the winding, I hand wound about 30 turns of the crown, then let it run about 15 minutes before the 66 degree timegrapher run. Then about 20 minutes in the oven to bring it up to 89 degrees, then that session on the timegrapher. Not much opportunity for self winding during all this as I wasn't wearing it. I didn't realize the timegrapher would reset the lift angle to default when powered down, which is why the first run showed 62 degrees instead of 63. The couple of times I've let it run down, the reserve was over 60 hours by a few. On every count it seems well within spec, except for the temperature thing. The previously posted technical guide (thank you) indicates the -15 to +25 spd should hold on the wrist at ambient of 5 to 35 C, and I've been well within that temperature limit, but as I said generally getting around +45 on the wrist. Even with diashock, I switch to a quartz watch when doing high shock activities like racquet sport or hammering etc.
  8. Here are shots at 66F (ambient) and 89F (my only environmental chamber, a proofing oven), both dial up. On the 89F shot you can see that the rate starts at +41s/d and gradually drops as the watch cools off again.
  9. Correction... of course that's 3 s/d/d.
  10. I recently bought a Seiko 6R15 based Alpinist. It keeps pretty good time if I keep it wound and sitting on a table in various positions, temperature in the mid 60's F. On the wrist it goes to around +45 seconds/day. Timegrapher shows similar results.. half or fully wound it runs way fast coming off the wrist or pocket and you can see it slide back to +/- a few seconds/day over the next 15 minutes as the watch cools off. I don't know what wrist temp means for the watch (skin on the back, ambient on the crystal), but guessing the difference is around 15 C, so the change would be 5 seconds/day/degree. That sounds like a lot (COSC limit is .6). What could cause this? Are Spron hairsprings more sensitive? Anything to do about it other than regulate for expected conditions?
  11. An intermediate approach when a full teardown service would cost more than the watch is to just replace the movement. If you have the Seiko 5 (7s26 or 36 movement) then for really just a few dollars more you can upgrade to a similar one with hacking and the option of hand winding (still a self winder as well). Even the high end Swiss brand Jaeger LeCoultre used to advertise movement swaps so you could get your watch serviced and ready to go in a few minutes.
  12. Discipline is Electrical Engineering. Mostly having to do with semiconductors but not professionally with solar cells in particular. I was exposed to them in school though. I was referring to wavelength relating to energy. I do know that it's inverse.
  13. Your run of the mill solar cell has a a threshold wavelength (energy per photon), A photon above that wavelength will release an electron and a photon below that won't. If you shine shorter wavelength on the cell you get no extra electric power, that extra energy dissipates as heat. You might be able to make multiple layer (and multiple threshold) cells, but that would cost and you would be dealing with multiple voltages. I don't see that happening in a watch,
  14. It seems like the interesting models are often already JDM. I haven't figured out why all the text on such watches is in English.
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