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praezis last won the day on September 29 2018

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About praezis

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  1. Poise is correct We can find many similar shaped pallets from that era, also called "moustache" pallet. But soon they found that the so increased inertia is much worse than some imbalance and these moustaches disappeared. Frank
  2. Ok, I had to look it up: Torque of the barrel M ~ E x I E= E or Young's modulus I= moment of inertia (with physical dimensions of spring, e.g. s^3) Means, influence of E is direct (linear), influence of thickness s is with 3rd power. My source (Prof. Glaser: Uhrentechnik) mentiones: E, springsteel, texture rolled: 225 E, Inox: 190 - 210 E, Nivaflex: 225 About the same as above. Frank
  3. I would regard this as nonsense, I am sorry. Old neatsfoot oil (when fresh) had better lubricating properties than modern oil. But wear of teeth and bearings (if not jewelled) gives more loss in power transmission. Hence imho the opposite is true. Frank
  4. I wrote an article about these old glass sizes once, in German however. In short: they all depend on "ligne" = 2.256 mm. x/16 Just multiply the figure with 2.256 mm. Eg: "19 8/16" = 19.5 x 2.256 = 43.99 mm x/8 Much more complicated: Zero is 22.56 mm. Integers x 1.128 mm. 1/8 = 0.14 mm Eg: "19 1/8" = 22.56 + 19 x 1.128 + 1 x 0.14 = 44.13 mm Sizes below 22.6 mm are calculated differently (backward from 22.6!) Frank
  5. @AdamC considering age and possible wear of your movement, your choice of a slightly thicker spring is intelligible. For a more modern, less wear movement I 'd chosen 0.10 rather and is what my calculator recommends. Nivarox/steel: strength changes in 3rd power with thickness, not linear. I suspect, needed decrease of thickness will be much less. @nickelsilver I buy from GR, too, but mostly the Inox variant. They have the same S-form as Nivarox springs. Frank
  6. what is the inner diameter of your barrel? Frank
  7. Now you can see the flaws of that movement. Before they were hidden by mere force of a too strong mainspring. Forget beat error for now, it is not your problem. It did not change (you did not rotate the collet?) but changing amplitude simply shows changing B.E. values. There is a bigger issue with your balance wheel, pivots, poise, hairspring. Frank
  8. VWatchie, thanks for your detailed answer to my short question ("Why?")! But in rodabod's quotation I saw questions only, not reasons (sorry, rodabod ) I tried to give a founded answer here. Frank
  9. Silver solder works well on brass cases. I used it many times to remove dents and damages. Laser welding is optimal for steel cases. Frank
  10. Glad to read the good points made here. If you contrast the danger of damaging the valuable hairspring against having a moderate beat error (that means almost nothing), guess what my advice is? Why? Frank
  11. Sounds like this is just a totally wrong mainspring. Do barrel diameter, spring length and thickness match? Frank
  12. Hello, short question, but a bit difficult answer. This error has little to no influence on performance as it is compensated by right and left swing of the balance wheel. There is little info on the topic. Values claimed in the net are just opinions without substantiation. The manual of a timing machine gave the answer: limit for the esc. error is 15 degrees. Here the unpowered escapement still rests in lift position. Unfortunately most TMs do not display the real esc. error (degrees) but just milliseconds that are not directly related to the real esc. error - ms value changes with amplitude and with bph despite a constant esc. error! One exception is PCTM that displays degrees, too. If you convert deg to ms, 15 degrees equates 9.6 ms @ 200 deg amplitude, @ 18000. Adjustment to 1/10 of that limit = 1.0 ms will be excellent. Frank
  13. Fraczish, if you are afraid of damaging something, leave it as is! A beat error of 2.5 ms does no harm at all, it annoys owners of Chinese TMs only. If you want to correct this "error", you can at least determine the direction of the needed move: Release the mainspring fully. The now loose fork will stand a bit more near to one banking pin. In the same direction the collet must be rotated a tiny bit. Then test again with balance wheel mounted. To get comparable values, the balance must swing with same amplitude on each test. Procedure can get time consuming like this writing! Frank
  14. John, paper tape machines of the good old days are not necessarily needed to detect wave periods of any length. I use this in my workshop: I found that more often teeth are guilty than wheels out of round. Frank
  15. That part most probably is nickel coated brass. Frank
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