Recent content by praezis

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    American PW Hamilton 18S 17J 940 full plate running fast after repair

    It is not very well visible, but in #41 the wheel looks like both rim cuts are of different width. A slightly bent wheel half can cause both the rate and poise issue. Frank
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    American PW Hamilton 18S 17J 940 full plate running fast after repair

    Hi, you got a very good advice by Chris Radek already, confirmed by John, too: add a light to medium weight washer opposite of the "heavy spot". That will solve both issues with one measure - put the balance to equilibrium and slow the rate just enough. Frank
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    alloy vs steel mainspring question

    i will answer with some data as a change. "Alloy" is often used but is a wishy-washy term. Modern mainsprings are available from Inox (lower cost) or from Nivaflex (higher cost, about 3x Inox). Ok, I had to look it up: Torque of the barrel M ~ E x I E= E or Young's modulus I= moment of...
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    hairspring collet

    Dewey, could you please disclose your mentioned "factory patterns"? What is their mystery beyond the known hairspring rules like size, windings number, pinning angle? Frank
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    Andra Zwingenberger Lathe

    A&Z collets and chucks will fit other 8 mm lathes, but their thread diameter is 7,0 instead of 6,85. There are threading tools available to widen threads of a collet holding bar. Frank
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    Timetrax Question

    Hi, If you want to know the right amount of adjusting the pendulum bob without try and error, no measuring equipment is needed. It can be exactly calculated (if you can :-)). Easyer is using the small free windows programm "Pendulum". Look here or download the latest version here. For finding...
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    pendulum swing amplitude question

    Hi, lower amplitude has the advantage that a certain amplitude variation will have less impact on the rate (limited by the point where movement can be detected at all and its accuracy). And - the lower the amplitude, the shorter the portion of free swing of the pendulum, unaffected by the...
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    balance Thiel balance

    Hi, more details are needed: what diameter is the movement (mm please)? Do you know the calibre or name of your movement? Is there any info on the dial? Frank
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    Blueing salt and solder pot

    double post removed
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    Blueing salt and solder pot

    Thank you for this variant of blueing! I suppose, the color appears after removing from the molten salt. Doesn't the salt stick to parts and cause stains? Is the pot removable or fixed to the device? Frank
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    Broaching a watch key

    I wonder if it would be sufficient to use a shallow starting hole for centering the square punch (diameter = square diameter)? This can avoid the guiding cylinder and give room for chips. Frank
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    Mystery tool

    and/or look up B.'s instructions in their catalog: Frank
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    4 jaw chuck

    Just a question: will those 10mm collets offered for Pultra, also fit a 10mm Lorch? Frank
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    Truing Caliper

    Good hint, Karl! I will try that method next time (if not forgotten till then). For bending I use a pliers with brass tips similar to this one: Bending in the caliper is questionable in my eyes, as it is stress for the rivet. Finally, none of my calipers are used any more: now I test in the...
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    Cimier "Chronograph" Balance staff

    I was afraid, you would reply so. OK: Frank

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