My completed Sextus
  • I thought I'd let everyone here at the forum know how much fun I had building the Sextus.

    There were several times when 'disaster struck' (I'll get into that later). I ordered the clock from here in the U.S. on January 6, 2015. David Atkinson sent it out on the 7th and it arrived on February 17th.

    I'm glad he sent the PDF instruction in advance as I had the opportunity to read it over and over and over again. I also joined this Forum and learned a lot about the Sextus and wooden clocks in general.

    I promised myself that I was going to take my time with this kit because in the past I dove right in on a different clock kit and it was over too soon. Well, I broke that promise and became 'obsessed' with this kit. I couldn't pull myself away from working on it nearly day and night. I enjoyed every minute of it!

    Everything was going smoothly until page 33 of the PDF instructions. The instructions could not have been any clearer, but I somehow managed to make a mistake that I did not discover until two days later. My heart sunk into my stomach the moment I realized what I had done.

    I glued parts 31A, 29E, and 28B incorrectly. There was no way to separate them as the glue had dried. I contacted David Atkinson about purchasing replacement sheets, but instead I decided to rectify the problem myself.
    With my jig saw, I cut laterally through part 29E which left half of 29E still glued to 31A and 28B respectively. With my electric hand held sander I sanded away what remained of 29E. I then remanufactured part 29E from one of the sheets. I was then able to glue the three pieces together (correctly this time). I had to do this again with the other side. Two day delay, problem solved!

    After the final assembly, I set the clock up in my garage for testing purposes prior to permanently setting it up in our living room. I was using a 2.5 gallon jug with about a gallon of water in it as a temporary weight. Had some difficulty getting it to run consistently at first. Even though the clock passed the 'blow test' and the pendula swing test, the clock would not run for more that 15 or 20 minutes.

    Frame Binding, I thought. So, according to the instructions, I decided to thin the arbors a bit more than I already had. That seemed to remedy the problem, however, this led to disaster number two.

    I had gone to bed before my wife one night and left the clock running in the garage hoping to find it still running in the morning. About midnight my wife woke me up in a panic saying that she thought someone was trying to break into the garage. Well, thankfully, it was only the clock. The weight went into a freefall and came crashing down onto the floor.
    The cause? I had thinned the drive arbor too much and this allowed the drive cog (Part 9B) to wobble on the shaft enough to come disengaged from the pinion 11E on the intermediate arbor allowing the freefall!

    I went to my local hardware store and purchased a length of brass rod and remanufactured a new drive shaft and this time I did not thin it as much. Problem number 2 solved.

    Now for final problem number 3. Unable to get the clock to run reliably after solving problem numbers 1 and 2, I decided that I hadn't filed the hook into the pallets sufficiently. So I filed on them a bit deeper. Still no lasting tick. So, I filed a bit more and a bit more until I realized that I had totally ruined them. So back to remanufacturing. Using my jigsaw again, I made replacement pallets from left over material, both right and left and filed only a slight hook.

    The clock has now been running flawlessly since then and I am now working on adjusting for accuracy. Then and only then will I have met the criteria necessary for the wife to allow the clock to adorn our living room.

    I have made several modifications, some aesthetic and some functional:

    Aesthetically, I had to make alterations to the clock dial. My apologies to Dave Atkinson , I just didn't understand the numbers on the dial (perhaps they are German Roman Numerals). You will see the modified dial in the video link below.

    I added thin metal discs with representations of clock dials to the pendula bobs. I found these at my local craft store. These were secured in place with tiny brass screws. I attached brass hubs to the pendula centers and another one at the axis point of the minute hand. I used heads of decorative brass tacks for these.

    Functionally, I had to add a small counterweight to the bottom of the left hand pallet using a half inch piece of arbor. The clock just refused to run without it. Because I am using a 4.5 kg drive weight (10 pounds), probably due to the added weight of the aesthetic enhancements, I felt it necessary to make several changes to the drive mechanism. I could not rely on the set screw in the winding hub to hold up during winding of the clock so I drilled a hole through the drive arbor and a corresponding hole through the winding barrel. I then inserted a brass rod through both holes.

    Also because of the added weight that I am using, I decided not to use the winding key provided with the kit. I squared the end of the drive arbor with a hand file and I am now using a traditional brass key. I also added a cord guide In order to keep the weight cord always toward the back of the winding barrel to help prevent frame sag,.
    Here is a link to a YouTube video of my finished Sextus Clock.

    http://youtu.be/zwn-YfGJMZk


    My thanks to Dave Atkinson for a great clock kit. It was worth every cent (1/100 of a Euro). And, thanks for the package of Haribos. I will now eat them!!

    Dave McDonald, Florida, U.S.A.

  • What a nice story! I wish everyone shares experience like that. I had difficulty to glue up the same parts of pendulum too. But I was not certain if I should cut and remake one of them that was done not 100% correctly. Now I'm pretty sure I will be able to make it.
    I like all your modifications. I was thinking about cord guide and I will make it for sure. I'm also thinking about making a large wooden key in shape of the butterfly and may be I will make it with a square too.
    Other mods I did:
    I added two washers on the winding arbor to prevent it from moving towards me.
    I had to change screws on winding springs to prevent them from getting loose. I drilled 3 holes in the wheel and glued in round metal nuts. Then I used special metal screws to fix springs and have them free to move.
  • An meiner Sextus hängt mittlerweile ein Bleibrocken con 5350 g, und damit läuft sie zuverlässig und genau, wohlgemerkt mit einer 1:3 - Übersetzung mit einer losen und einer festen Rolle, die mir für das Gewicht eine Sinkrate von 20 cm/24 h bringt.
    Nach meiner Beobachtung werden die meisten Uhren mit einem unnötig großen Gewicht malträtiert, weil das der bequemste Weg ist, die Uhr am Laufen zu halten. Er schafft aber gravierende Nachteile in Form von starkem Verschleiß an praktisch allen bewegten Teilen, vom Pendel vielleicht mal abgesehen. Zusätzlich wird dadurch auch noch der Rahmen verzogen mit dem Effekt, dass die Wellenlager nicht mehr genau fluchten und damit klemmen können.
    Mit den verschiedenen Tips aus dem Forum kann die Reibung sehr weitgehend eliminiert werden. Wenn dann aber die Uhr mit minimaler Kraft läuft, ist es nach meiner Überzeugung durchaus hilfreich, zumindest die schneller laufenden Räder -vielleicht vom Hemmungs- bis hin zum Minutenrad- und Zeiger auch auszuwuchten.
    Um einem Verzug des Rahmens vorzubeugen, scheint vordergründig meine 1 : 3 - Übersetzung kontraproduktiv zu sein, arbeitet sie doch mit dem dreifachen Gewicht. Tatsächlich wirkt aber nur 1/3 des Gewichts auf das Uhrwerk, denn speziell bei der Sextus hat man hinter dem Uhrwerk ausreichend Platz für die feste Rolle, sodass 2/3 des Gewichts dort unschädlich für die Uhr aufgefangen werden.
    Ferner ist die Tiefe des Uhrwerks so großzügig bemessen, dass man hier leicht die Wellen und Stollen verkürzen kann: damit verkürzt man auch den Hebel, an dem das Gewicht das Uhrwerk verformen kann. Meine Sextus kommt da jetzt auf eine lichte Weite von 39 mm. Die Schnurwalze wird damit allerdings recht kurz, zumal ja auch die dreifache Schnurlänge aufgewickelt werden muss. Um sie trotzdem einlagig unterzubringen, habe ich die relativ dicke Schnur durch eine dünne Edelstahllitze ersetzt. Zusätzlich Platz gewinnen könnte man aber auch noch, wenn man das Gesperr hinter das Walzenrad setzt und die Endscheibe aus dünnerem Sperrholz macht.
    Schließlich habe ich auch noch die Anregung aus dem Forum aufgegriffen und den Rahmen nicht nur verschraubt, sondern komplett verleimt.
    Wieviel jede einzelne Maßnahme gebracht hat, kann ich nicht genau sagen. Das Gesamtpaket ist aber surchaus befriedigend.
    Peter