Problem with the Graham escapement

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Problem with the Graham escapement

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  • #322958
    Jens Eirik Skogstad 1
    Participant
      @jenseirikskogstad1

      Hi folks.. I has a old Gustav Becker 400 days clock serial number 4444. There is problem with escapement where the pallet hit the top of escapement wheel.

      Is it the solution to fix the problem?

      See this in youtube –> https://www.youtube.com/watch?v=AZ0j08_ddmI

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      #3775
      Jens Eirik Skogstad 1
      Participant
        @jenseirikskogstad1
        #322971
        John Haine
        Participant
          @johnhaine32865

          Isn't that what it's meant to do?

          #322978
          Michael Gilligan
          Participant
            @michaelgilligan61133

            These notes may be of some help:

            **LINK**

            http://www.nawcc-index.net/Articles/Murray-400-day.pdf

            MichaelG.

            #323002
            John Haine
            Participant
              @johnhaine32865

              Jens, the video you linked to seems to show a pallet correctly engaging with a wheel tooth. What is the actual symptom of the problem with the clock?

              #323018
              Jens Eirik Skogstad 1
              Participant
                @jenseirikskogstad1

                The pallet hit first at the top of tooth, not into the wheel tooth before the tooth is stopped on pallet. The other pallet is ok.

                #323029
                John Haine
                Participant
                  @johnhaine32865

                  Ah! I see what you mean. Two thoughts.

                  Is the clock vertical, so the pendulum swing is the same each side of the escapement?

                  Is perhaps the amplitude a bit low, indicating that it needs a clean/relubricating?

                  #323031
                  Jens Eirik Skogstad 1
                  Participant
                    @jenseirikskogstad1

                    The torsion pendulum is set to correct, swing in same way in each side, and the clock is in vertical.

                    The clockwork is cleaned. But i has a mistake: Is the escapement out of order (The pallets is adjustable) or need recentered the ancor in distance to escapement wheel? I can see there is a excenter adjusting for centering between ancor and escapement wheel.

                    #323200
                    Jens Eirik Skogstad 1
                    Participant
                      @jenseirikskogstad1

                      I has checked all parts in escapement, learned out the escape wheel is worned. Also not sharp pointly teeth. I can se the teeth on escape wheel is curved instead of straight teeth where the pallets are on contact. Some time the teeth is pressing the palett out of rest position ("in lock" position) and fluttering 6-8 teeth past the pallets periodically.

                      Then a question: Is it dificult to make a new escape wheel? Have someone a tips or to tell how to create the escape wheel?

                      #323201
                      Jens Eirik Skogstad 1
                      Participant
                        @jenseirikskogstad1
                        Posted by Jens Eirik Skogstad on 24/10/2017 08:59:44:

                        I has checked all parts in escapement, learned out the escape wheel is worned. Also not sharp pointly teeth. I can se the teeth on escape wheel is curved instead of straight teeth where the pallets are on contact. Some time the teeth is pressing the palett out of rest position ("in lock" position) and fluttering 6-8 teeth past the pallets periodically. (Escape wheel passes some teeth through the escapement)

                        Then a question: Is it dificult to make a new escape wheel? Have someone a tips or to tell how to create the escape wheel?

                        #323235
                        Michael Gilligan
                        Participant
                          @michaelgilligan61133

                          Posted by Jens Eirik Skogstad on 24/10/2017 09:07:12:

                          Posted by Jens Eirik Skogstad on 24/10/2017 08:59:44:

                          Then a question: Is it dificult to make a new escape wheel? Have someone a tips or to tell how to create the escape wheel?

                          .

                          Jens,

                          As you have asked the question twice … I will try to answer:

                          In principle, it is not difficult … it is 'only' a matter of either buying [at substantial cost] a multi-tooth cutter, or making [with great skill] a flycutter to match the original profile. … Then use whatever means you have at your disposal to index and cut the wheel … Then it's 'just' a matter of mounting the new wheel on the original arbor, or a new replacement.

                          Alternatively: as these are mass-produced items, you should be able to purchase one !

                          The Horolovar 400 Day book mentioned in the link I gave previously should let you, or a reputable supplier, identify the part.

                          MichaelG.

                          #323251
                          John Haine
                          Participant
                            @johnhaine32865

                            "Wheel and Pinion Cutting in Horology" by J Malcolm Wild describes the process. You may be able to get a cutter of the right size here or here or here. Or you can make a fly cutter fairly easily I expect though I can't readily find instructions.

                            Try this book on gear cutting.

                            I've sent you a PM.

                            #323867
                            Jens Eirik Skogstad 1
                            Participant
                              @jenseirikskogstad1

                              img_2123.jpgimg_2122.jpg

                              img_2116.jpgimg_2119.jpgimg_2120.jpg

                              These photo where i took inspection of worned escape wheel under microscope.The teeth on escape wheel is curved instead of straight teeth where the pallets are on contact. Some time the teeth is pressing the palett out of rest position ("in lock" position) and fluttering 6-8 teeth past the pallets periodically. (Escape wheel passes some teeth through the escapement) The Pallets seem ok.

                              Edited By Jens Eirik Skogstad on 27/10/2017 10:56:13

                              Edited By Jens Eirik Skogstad on 27/10/2017 10:58:06

                              #323868
                              Jens Eirik Skogstad 1
                              Participant
                                @jenseirikskogstad1

                                l.

                                Edited By Jens Eirik Skogstad on 27/10/2017 10:56:32

                                #323905
                                Michael Gilligan
                                Participant
                                  @michaelgilligan61133

                                  ^^^

                                  Adequate evidence that you need to buy/make a new wheel [unless you are extraordinarily good at bending the teeth back to their intended shape] … I can't say more, because I don't know if you have read my previous posts.

                                  MichaelG.

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