Expert: Martin Meyer - 9/6/2007

Question
Martin,
I have an Emperor clock kit with an 1171-850 Hermle movement which I purchased in 1995. It has run fine from that point until a couple of months ago when the click spring and cable broke for the time weight drum. I purchased a new cable and drum and installed them, and had the problem of the weight not traveling all the way down, or being able to get it to stop when winding it up. It would actually run clean up into the movement if I keep winding. At that point I let it run until it quit halfway down, removed and put back the idler gear for the time drum(after applying tension because it was locked up) and the clock ran and the weight traveled all the way to the bottom like it should. Now it will only wind up about halfway and then stop. What is the trick to get this cable synchronized to the correct rise and fall?

Answer
Hi Raymond,
    Adjusting the stopworks has driven many a clock repairer nearly crazy. There are two gears, a gear on the winding arbor and a stopworks gear (idler gear). Start by releasing the click and unwinding all three cables fully, until the stopworks stops them.
    Your problem is with the time drum, which is the center drum. You will see that two of the stopworks mechanisms are identical and one has the stopworks gear on the opposite side from the other two. On the 1171, the time drum should be identical to the strike (right hand) drum, that is, the stopworks gear on the left of the arbor gear.
    The easy way to align the gears is to match the fully unwound position to the identical (strike) stopworks.
    Note the position of the cable end where it attaches into the slot in the cable drum when in the fully unwound position, for the two correct drums. This is usually about 1/2 to 3/4 of a turn of the drum from the slot-at-the-bottom position. Use this same amount as a starting position when you insert the time-side cable drum into the movement. This little bit of starting wind is to prevent the cable from coming out of the drum when it is fully unwound.
    To explain the setup in more detail, If you align the long tooth on the arbor gear with the shallow bottom on the stopworks gear so that they directly face each other, they will not fit together. Because the arbor gear moves counterclockwise when the clock RUNS (clockwise when it winds), and the stopworks gear is on its left (for the time train), you must move their intersection UP just enough for them to mate. In this position, you will see that the arbor will not run (unwind)any farther. So this is the correct UNWOUND position.
    You should be able to wind the cable onto the drum approximately 18 turns before the stopworks stops it near the top. In some cases, you will find that all three fully wound cables do not align exactly level. If you want the adjustment to be perfect (visually nice, but not essential), you will have to change the alignment of the offending stopworks by one tooth. You may adjust it in the wrong direction, and have to undo your change and make the one-tooth alignment in the other direction. (I find this part confusing, and sometimes just do it trial-and-error.) You may have to wind and unwind and make adjustments several times to get everything perfect.
   Movement manufacturers sometimes make modifications over time to their movements. If my instructions are backwards, just reverse the procedure (one tooth below instead of above straight alignment) to get the correct setting. (For example, there is a very similar movement, the 1161, in which the stopworks alignment is the opposite of the 1171.)
    I hope this description of a very confusing setup is clear and you can get your movement set up correctly.