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DouglasSkinner

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DouglasSkinner last won the day on September 15 2017

DouglasSkinner had the most liked content!

About DouglasSkinner

  • Rank
    WRT Addict
  • Birthday January 16

Profile Information

  • Gender
    Male
  • Location
    Berkeley Springs, West Virginia, USA
  • Interests
    Restoration of vintage watches. Servicing watches. I also worked as a scientist (chemical physics) and statistician. I have recently tied my love of science with watchmaking by undertaking a mathematical study of the Archimedes spiral which forms the hairspring in most watches.

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  1. I have an ETA 2750 movement and I need to replace the mainspring. My catalogs don't cover this caliber. The current mainspring, based on my measurements has the dimensions Dennison (Metric), W: 5 1/2 (1.45 mm), T: 9 (0.13 mm), L: ~ 14 1/2" (368 mm). However, due to its age and the fact that it's been serviced before I'm not completely sure the old spring is the correct one. So my first question is are these the right dimensions for the proper mainspring for the 2750? My second question is does anybody know some part or catalog numbers for the correct mainspring by some different manufactures of springs, such as Marco, Nu Vigor, Sandsteel, etc.? I have some cabinets of mainsprings from which I might be able to get one but I need to know the a catalog/part number--some number I can cross reference to what I have. Hope this makes sense. Thanks.
  2. Thanks for the help, especially the tips about making the staff. I can see if I can get some CO2 cartridges. Didn't know N2O cartridges. Not sure you can get them here in the US.
  3. I got some stuff from Esslinger and have had a hard time working with it. It's almost impossible to cut into pieces. Tried using a jewelers saw, no luck. Graver won't part it--at least not in any reasonable length of time. Doesn't want to be cut into pieces with snips either. Definitely not getting curls of sworf and, yes, I am making dust. Takes forever to make any progress. Tried to anneal it but still application of my graver still yields a kind of brittle powder. Didn't think about finishing down to size with the Jacot tool. Thanks!
  4. Sorry! Didn't just learned that this topic has already been addressed pretty thoroughly here: However, if you have any other comments they'd still be appreciated.
  5. Am looking for a source for good steel to make staffs from. Got some from Esslinger recently and it appears to be crap. Way too hard and won't anneal (at least I can't do it). Any suggestions for where I can obtain it. I'd like a range of sizes from, say, 0.5 mm to 3 mm. Following link is the stuff I got from Esslinger: https://www.esslinger.com/staff-and-pivot-watch-and-clock-wire-rod-assortment-blue-steel-55-1-93mm-12-pieces/
  6. Thanks! I'm not experienced enough to envision how to use a faceplate and cross slide to bore the hole. Do you have any pictures so I can see how it works? I have a Seitz jeweliing tool and I was just going to use one of the reamers to bore out the hole in the plate. I've measured the diameter and think a number 230 reamer will work (actually 2.99 mm). I plan to turn down some brass stock to 2.30 mm. Then I plan to drill a hole (size 24 as near as I can tell) a little undersized. Measuring the thickness of the plate will tell me how thick the bushing needs to be and I'll part it at that thickness. For me the tricky part will be fitting it into the hole. I'll need to get the outside diameter right so I won't have either a loose or overly tight fit--my lathe skills aren't all that great so I may have to make several attempts. Then I plan to use a small broach to bring the hole to the proper diameter. Check for end shake and side shake. Spin it in place and then in train with the other wheels. If it spins okay and all looks properly righted I assume it will be okay. How does that sound? Thanks again! Doug
  7. You're absolutely right! I just let it run a short while. It's now disassembled and I'm making ready for repair.
  8. I think you're right. I need to practice my lathe skills anyway so I'll give a try at turning a bushing. Thanks for the comment. Doug
  9. It is a nice case. A "fold out". I've been refurbishing it. It's got a plastic crystal which I think I'll replace with a vintage glass one. As for replacing the movement itself, I'd be interested in upgrading the quality if I can find one. Not sure which Elgin 16s movements will fit in the case. Naturally if I do repair it I know I'll never get back the investment of time. I do them largely to practice my skills. I could re-jewel it but I think I'll practice turning a bushing instead. I can see already that the movement is very forgiving. The escape wheel pivot hole is pretty egged. I put it together and let it run for a day and it kept time--not great but surprising, nonetheless. Re-bushing will probably reduce the positional errors somewhat; though I'm not very experience in this area. Thanks for your comment. Doug
  10. I have a nice old Elgin 7j (Model 291) pocket watch which I've just resurrected. It's running a little fast and possibly the reason is that upper bushing for the escape wheel is a little bit egged. I'm going to have to replace it. The question is how? Should I find a jewel which fits and make a setting? Or should I make a brass bushing. I say brass because the original bushing is just the plate itself and so is plated brass. The lower bushing looks fine. Should it be replaced too? Any suggestions?
  11. I'm looking for advice on what kind of steel stock makes good flat springs for watches? What do you recommend? Where can you get it? Thanks!
  12. I sympathize with you. I haven't quite mastered this yet. Didn't think about the quality of the pegwood. Thanks!
  13. Did you buy the pegwood directly from Horotec?
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