The best quartz (fake) torsion pendulum drive that I have seen.

Discussion in '400-Day & Atmos' started by lmester, Oct 14, 2012.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. lmester

    lmester Registered User
    NAWCC Member

    Dec 30, 2009
    442
    5
    18
    Male
    I manage HVAC systems for a school district.
    West Virginia
    Country Flag:
    Region Flag:
    I've seen several different fake torsion pendulum systems. Fake because the pendulum is not used for keeping time. The best one that I have worked with is shown below. It uses only one battery to run the clock and It's hard to damage. Your grandkids can spin the pendulum around like a top without any damage to the mechanism.

    It's rotation also looks like the real thing. It slows down at each end of it's rotation. I've seen some that rotate at a nearly constant speed and then abruptly slow down and reverse direction.

    There was no maker shown on the clock. When I took the cover off of the movement I saw that it was made by Haller.

    The worst pendulum drive mechanisms that I have seen look like a generic quartz movement with a black plastic case. They take a single AA battery and have a shaft on top to drive the pendulum. They must wear out quickly. I buy used modern quartz anniversary clocks to get the glass dome for use on older mechanical clocks. I've not yet bought a used clock with this type of pendulum drive that was still working. The quartz movement is OK but the pendulum drive was dead.

    I was also going to post a picture of one of those junky pendulum drive mechanisms. I can't find one. I think I tossed them all in the trash...

    Haller quartz fake torsion 002.jpg Quartz fake torsion 005.jpg Quartz fake torsion 007.jpg
     
    Berry Greene likes this.
  2. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
    13,666
    63
    0
    Calif. USA
    Hi
    I assume that if a kid spins it, it just runs
    of the end of the rack?
    Tinker Dwight
     
  3. watchin

    watchin Registered User

    May 10, 2012
    84
    0
    0
    Country Flag:
    I inadvertantly ended up being the owner of an all plastic 400 day look alike. It was a sight unseen purchase with no return rights. It had no glass or brass parts. Full size gold plastic movement, pendulum, base and plastic dome. I keep it displayed in my mud room to remind me of the 'stuff' that is floating around out there. Fortunately it was under $10 but in it's prime is not worth even that.
    A glass dome would have helped me lick my wounds and feel pretty good, but alas, scratched up clear plastic.
    I really don't think my grandkids would be interested in it as a target. I hope I don't come across as a curmudgeon. I love mechanical clocks.
     
  4. lmester

    lmester Registered User
    NAWCC Member

    Dec 30, 2009
    442
    5
    18
    Male
    I manage HVAC systems for a school district.
    West Virginia
    Country Flag:
    Region Flag:
    Right. It just goes to the end of the rack & slips. When it stops spinning it goes back to the center. If there was just some way to do something to protect real torsion clocks from this problem it would be great. I guess then I wouldn't find so many of them for sale that just need a new suspension spring!
     
  5. David B Pendley

    David B Pendley Registered User
    NAWCC Business

    Aug 25, 2000
    608
    3
    18
    Country Flag:
    Region Flag:
    These units are available through Lorichron in Asheville, NC. I think they were made by Haller.
     
  6. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    #6 Cheezhead, Oct 14, 2012
    Last edited: Oct 14, 2012
    I have one of these in my small collection of inexpensive quartz anniversary clocks. The two slender white levers that you see in Mr. Imester's picture are very flexible and are joined at the common pivot seen at one end The two levers are rigid enough to operate the pendulum if no interference is presented. I concur with Mr. Tinker Dwight and Mr. Imester in that if the pendulum is needlessly spun, the rotary pendulum operating gear simply runs off either end of the rack and the flexible levers accommodate this disturbance without damage. By the same way, if the pendulum is needlessly stopped, the timing portion of the clock is neither slowed nor stopped; keeps on running. My clock is brand labeled Seth Thomas. This appears to be a very clever design from Haller who are still in the business of selling clocks. In addition to other advantages of a quartz clock this one is quite insensitive to the lack of a perfectly level locating surface.
     
  7. bangster

    bangster Moderator
    NAWCC Member

    Jan 1, 2005
    19,094
    294
    83
    utah
    Country Flag:
    Region Flag:
    The best I've seen is the Kundo quartz movement, which is much simpler than the Haller shown above. Its action is natural, and mimics the behavior of a "real" pendulum quite well, because it works the same way.

    Kundo quartz1.jpg Kundo quartz 2.jpg

    It has a regular suspension spring, but instead of a fork it has a single pin projecting from the spring into the movement. The pendulum is impulsed in one direction only by a single-toothed wheel (red arrow) that is spring-loaded, and gives a push to the pin on the suspension spring. The only difference between the Kundo and a "real" pendulum is that the impulsing force is independent of the time-keeping part of the movement.

    Kundo quartz1.jpg Kundo quartz 2.jpg
     
    Berry Greene likes this.
  8. etmb61

    etmb61 Registered User
    NAWCC Member

    Oct 25, 2010
    2,218
    93
    48
    Retired Avionics Technician
    Mascoutah, IL
    Country Flag:
    Region Flag:
    #8 etmb61, Oct 15, 2012
    Last edited: Oct 15, 2012
    I have one of the Kundos as well. I do not think that is a quartz movement, rather a electro/magnetic balance wheel.

    Mine has a mechanical pendulum (#75) exacly like those used on the key wound clocks, complete with the locking lever, hanging from suspension 49.

    You can't tell it's electric until you get up close and hear the fast ticking.

    Eric
     
  9. bangster

    bangster Moderator
    NAWCC Member

    Jan 1, 2005
    19,094
    294
    83
    utah
    Country Flag:
    Region Flag:
    The one I have now says "quartz" on the dial.

    I think it's a matter of how the magnetic impulses are timed, that makes it quartz.
     
  10. MartinM

    MartinM Registered User

    Jun 24, 2011
    2,961
    79
    48
    Male
    Medical Insurance Systems Analyst
    El Dorado, CA
    Country Flag:
    Region Flag:
    The first electronic versions were not quartz. They were an offshoot of the swinging pendulum versions of the Kundo and Junghans electromechanical clocks. They used a magnetic trigger to impart a maintaining impulse on the balance wheel and were timed very much like any other hairspring clock. Most of these type used an additional such system for pendulum movement. In all but one Kundo model I've seen, the pendulum wasn't actively participating in the timing for the clock. But I admit to having limited exposure to the full cadre of types.

    All of the "quartz" clocks I've seen keep time and move the hands via a quartz-controlled oscillator and divider circuit and use the motion occurring in that process (Usually via an unused 'seconds' shaft to impart oscillation is a torsion pendulum via a lever, cam or offset shaft.

    TIP: Many times these quartz clocks use a 'button' to cover the hand arbors This button is pressed onto a fully functional seconds shaft. If it's pressed on too hard, the clock can't run. If it had been a real seconds hand, instead of a button, it'd be trivial to catch; but as a button, it's not so obvious and you can spend a lot of time working through it and having the clock run right up until you're sure it's good and put it all back together.
     
    Berry Greene likes this.
  11. bangster

    bangster Moderator
    NAWCC Member

    Jan 1, 2005
    19,094
    294
    83
    utah
    Country Flag:
    Region Flag:
    If it calls itsownself "quartz", I'll allow as how it's quartz. :whistle:

    As I said, with this type, pendulum action is independent of timekeeping. This means, among other things, that the strength of the suspension spring doesn't matter, since the period of the pendulum has nothing to do with the period of the clock.
     
  12. MartinM

    MartinM Registered User

    Jun 24, 2011
    2,961
    79
    48
    Male
    Medical Insurance Systems Analyst
    El Dorado, CA
    Country Flag:
    Region Flag:
    I wonder how the mechanical balance keeps sync with the quartz timebase?. It must be close enough that the quartz timebase simply acts as a reinforcement/correction for the period of mechanical oscillation. Sort of like a Phase Locked Loop. If it's not a pretty close match, I'd think it'd eat up batteries, fast, though.
     
  13. lmester

    lmester Registered User
    NAWCC Member

    Dec 30, 2009
    442
    5
    18
    Male
    I manage HVAC systems for a school district.
    West Virginia
    Country Flag:
    Region Flag:
    That's a nice fake! It even has a real suspension spring.

    I agree with the other replies. I don't think this is a quartz movement. If it were quartz, there would be no reason for the balance. The quartz crystal is regulating it. The first two pictures are of similar looking movements. I've had both of these apart and can verify that they are not quartz. There is no crystal just a simple one transistor circuit. You could be sure by looking at the circuit board on your movement. If it's quartz there will be a crystal and an I.C. to divide the crystal frequency down to get 1 second pulses. In newer movements the I.C. is just a blob of epoxy on the circuit board.

    I can't imagine why the manufacturer would label it as quartz?

    The last picture is a Haller with a real pendulum. It's not quartz but is electromagnetically impulsed. The pendulum is used for timekeeping. I'd think that this could still be called a fake torsion clock. When I look at the design I'd say it basically works like a Hermle floating balance. It has a flat wound hairspring instead of a torsion spring. Also the flat wound spring keeps the pendulum floating in between two jeweled bushings. No end thrust on the arbors.

    I think it's interesting to see all of the different designs that have been used to simulate a real torsion clock. Im sure that if we keep looking we'll find even more ways that it was done.
     

    Attached Files:

  14. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    40,269
    624
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    The GTB is another one that uses a hairspring arrangement.
     
  15. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    134.jpg

    Here is another "fake" torsion pendulum drive to add to what Mr. Imester has started and includes a detailed description of the mechanism that operates the rotary pendulum a single AA battery powered German Linden quartz anniversary clock.

    The pendulum is suspended by a vertical flat wire which has attached to it a flag whose edge is visible just above the gray star wheel. The flag is given a periodic push to the left at its bottom end by the CCW slowly rotating star wheel. The star wheel is connected to the step motor gear train through a slip clutch that permits the timing portion of the clock to continue even though the star wheel is periodically stopped by the white lever and to some extent, the flag. The white lever, suspended by a horizontal pivot pin that is not visible behind the black upper suspension wire holder, adds to the pendulum's amplitude by holding the star wheel stationary until the flag is better ready for another push. Visible at the lower end of the white lever is a horizontal extension that stops the star wheel which is held stationary until the pendulum is at a point in the return direction to where the flag pushes the visible tab on the left side of the white lever to the right, unlocking the star wheel to permit it to rotate again and give the flag another push.

    The pendulum's rotational excursion was running at about 450 degrees. As an experiment the white lever was held out of play and the pendulum's rotation continued and did not decrease appreciably. The white lever has an extension to the left at the top which may be a counterweight to reduce the force that the lever imposes on the gear train to reduce battery power consumption. Visible to the right of the upper suspension mount is an extension of the white lever that is confined between two fixed surfaces to act as limiting stops in both directions. The thin horizontal flat spring is part of the upper suspension spring mount and acts as a shock absorber for when the clock is handled roughly. The purpose of the white lever's upper stop is not apparent but the lower stop appears to keep the white lever from dragging against the star wheel to minimize friction and save battery power.

    It may be reasoned that the stiffness of the pendulum suspension wire, the inertia of the pendulum and the speed of the star wheel must be carefully coordinated. There is no protection against damage incurred if the pendulum is needlessly spun and the force to operate the pendulum does not appear to be as positive or robust as the Haller design described previously but in fairness, it works as intended.
     
  16. bangster

    bangster Moderator
    NAWCC Member

    Jan 1, 2005
    19,094
    294
    83
    utah
    Country Flag:
    Region Flag:
    Lemme see if I understand.

    In a regular quartz, the rate is determined by magnetic impulses regulated by the crystal. (I'm clear about that.)

    In the clocks we're referring to here, the only thing the battery does is power the movement by providing juice to the electromagnet.
    The rate, as with any balance movement, is determined by the effective length of the hairspring. It needs no regulating crystal, and doesn't have one.
    Okay so far?

    Next question: doesn't the juice have to get to the electromagnet in intermittent pulses, rather than a steady stream? (As you can see, my knowledge in this area is really limited.) Or maybe I don't understand how dc motors work. Anyhow, if it is pulses rather than stream, what regulates the pulses? And don't their frequency have an effect on the rate of the clock?

    Please clue me in on this.
     
  17. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
    13,666
    63
    0
    Calif. USA
    Hi Bang
    Pulses are timed by the swinging magnet in most of these cases.
    As the magnet swings into the coil, a tickler winding caused the transistor to turn
    on. This causes a feedback loop that increases the feedback holding the current
    through the coil and causing the swinging magnet to increase speed. The initial
    feedback is limited in time by a capacitor ( usually ), timed such that it can only
    start the transistor. Once the magnet begins to move out of the field, a reverse
    voltage is picked up by the tickler winding. This causes the transistor to turn off
    and wait for the next passage of the magnet.
    This is very similar to the way the ATO clocks work, with mainly slight changes to
    allow it to work with silicon transistor, instead of germanium.
    Tinker Dwight
     
  18. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    137.jpg

    Here is a German Made Westclox with the movement made by Hermle. It appears that someone put some twists in the suspension spring while starting the pendulum as this one is not self starting. It works similarly to the Linden but is a simpler design. Note the hairspring inside the star wheel that functions as a slip clutch. The white plastic "C" shaped star wheel trip lever is barely visible under and below the star wheel. The pendulum has a rotational excursion of almost 2-1/4 turns or about 800 degrees. Also note the small size of the movement. The cost savings compared to a traditional mechanical movement must be immense!
     
  19. lmester

    lmester Registered User
    NAWCC Member

    Dec 30, 2009
    442
    5
    18
    Male
    I manage HVAC systems for a school district.
    West Virginia
    Country Flag:
    Region Flag:
    Bangster,

    Maybe a simpler but not entirely accurate way describe this. Look at the first movement in my post #13. You can see that the coil is made of red and green wire. It's actually two coils. A trigger coil (tickler in tinkers post) and an impulse coil. The trigger coil is used to sense the position of the balance. That's how impulse is provided at the proper point of the balance's rotation. When the magnets approach the trigger coil it causes the impulse coil to be briefly switched on.

    This circuit has only a few parts but it's operation is fairly complex. It does basically the same function as the escapement in a fully mechanical clock. In a mechanical clock you have an escape wheel and pallets. Only a few parts but for me the most complex part of a mechanical clock. If I remember correctly, you helped me get the lock and drop set on a 400 day clock when I was having problems with it.

    Finally, there has been a lot of discussion of this type of electronic movement in the electric clocks area.
     
  20. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
    13,666
    63
    0
    Calif. USA
    Hi
    There are two types of pendulum drives shown on these posts.
    Some are the single transistor drive that independently drives the pendulum,
    with no relation to the quartz time.
    The other, is like seen in #15, #18 and I think #7 that periodically have a method
    of self syncing to the pendulum and adding to the swing.
    You'll note that these have something that lets the pendulum pass by if it is on
    the wrong direction of travel and then push it in the right direction.
    The are mechanically driven by the quartz movement but still are not related to the
    time of the quartz movement.
    Tinker Dwight
     
  21. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    142.jpg

    Here is a German made Bulova quartz anniversary clock with a conventional size Hechinger movement that incorporates a clever self starting rotary pendulum drive. The upper gear with its tooth tips seen protruding from behind the kidney shaped lever is driven at 1 rpm by the step motor and engages with the lower gear, also behind the kidney lever. The kidney lever is free to pivot on the upper shaft and the lower gear turns on a stub axle. The kidney lever is shown in its resting position with the pointed portion aimed downward until the horizontal pin fastened to the suspension spring engages as shown between two gear teeth that stops the lower gear. Then the kidney lever begins to rotate CCW and pushes the horizontal pin to the right to rotate the pendulum until the horizontal pin becomes disengaged from the lower gear and by gravity the kidney lever swings back to its rest position to wait for the next push cycle. The pendulum ball cluster rotary excursion is about 1-1/2 turns.
     
  22. David S

    David S Registered User
    NAWCC Member

    Dec 18, 2011
    7,099
    186
    63
    Male
    Professional Engineer - Retired
    Brockville, On Canada
    Country Flag:
    Region Flag:
  23. lmester

    lmester Registered User
    NAWCC Member

    Dec 30, 2009
    442
    5
    18
    Male
    I manage HVAC systems for a school district.
    West Virginia
    Country Flag:
    Region Flag:
    I found the junk pendulum drive that I mentioned in the first post. They don't hold up very well. I put some oil on the pivots and was able to get it to run. It's sloppy and It rattles. The plastic bushings are worn out. The last picture is a similar motor made by Elgin. It's been running without problems. One of the few pluses of a quartz movement. It's sealed. I used the dome from this clock on a mechanical clock. It's sitting on a shelf in my workshop. Dust all over it and it's still running.
     

    Attached Files:

  24. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    198.jpg

    This is an anniversary clock pendulum drive that came to my mind when at first with no photo, Mr. Imester described one as being junky. This clock is branded Timex with a Shinfuku quartz movement. Please be aware of the missing hairspring that would normally be located immediately underneath the upper bearing, connected to the pendulum shaft and to the bottom end of the white lever. The white lever oscillates left and right, pulling and releasing the hair spring to rotate the ball cluster. The hairspring provides compliance for overshoot and undershoot to give sufficient pendulum rotation.

    A problem with this design is that the forces provided through the hairspring to oscillate the pendulum are too low relative to the friction presented from the lower and upper bearings. Even some graphite on the lower and upper bearings in addition to a little oil was not enough to overcome resistance to rotation to permit the pendulum to continue to oscillate for more than a few minutes. While attempting to remedy the situation, I ruined the hairspring and removed it. The solution may be a separate battery powered pendulum drive from Merritts for under 10 dollars. Mr. Imester may not approve but it may be my only easy option. It's a nice looking clock with red and yellow roses and green rose leaves on the white porcelain base and white porcelain dial.
     
  25. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    214.jpg

    This wood and glass anniversary clock is branded Hamilton and operates the timing and pendulum from the step motor movement branded Haller 993. The pendulum operating mechanism, barely visible through the translucent movement cover appears to be similar to a conventional windup alarm clock escapement. Through a slip clutch the step motor turns an escape wheel that operates a pallet fork that operates the pendulum instead of a balance wheel. Note the pendulum control hairspring below the quartz movement case. The Haller design pendulum suspension like a Haller GTB would not stay running until a little powdered graphite was added to the freshly oiled upper and lower pivots. The mounting feet needed experimentation by shimming them with playing cards until the pendulum would reliably run. Note the pendulum locking lever for transport.
     
  26. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    266.jpg

    This anniversary clock is branded Dunham and was made in West Germany. Both the quartz step motor operated timing movement, branded UTS, and the pendulum drive run from the same AA battery. The pendulum drive design is a variation of what Mr. Imester posted on 10-16-12, the main difference being that this one has a hairspring below the upper pivot bearing to control the pendulum excursion and the pendulum does not affect the clock timing accuracy. This pendulum drive is not self starting but does start with the slightest movement. It has been a reliable runner.
     
  27. Cheezhead

    Cheezhead Registered User

    Dec 30, 2010
    175
    7
    18
    Male
    Retired Mech Eng Tech
    Wisconsin
    Country Flag:
    Region Flag:
    31.jpg

    This is a Spartus model 6068 anniversary clock; measures 11-1/2" tall and was made in Louisville, MS. It has a Kienzle movement that runs from a single AA battery to operate both the timing geartrain and the pendulum. It runs very well with a pendulum excursion of about 1 turn. The star wheel runs at 1 rpm through a slip clutch and engages with a flag fastened to the torsion spring. Note the flag limit stop above the star wheel protruding from the back of the movement case. The limit stop keeps the flag where it will engage the next star wheel tooth no matter how far the pendulum rotates in the return direction. The flag rests against the stop when there is no battery power so the pendulum is self-starting. The clock is made almost entirely of plastic including the dome. A quality brand quartz movement such as this Kienzle with an elegantly simple and reliable pendulum operating mechanism deserves a better quality clock in which to hold it. It is, however, a clock that demands little from its owner; a new battery when needed and a time reset every few months.

    This is the last single battery operated quartz anniversary clock movement with pendulum drive that I will post as I have no other variations as of now. If I find another, I will post it here. I thank Mr. Imester for starting this thread.
     
  28. Berry Greene

    Berry Greene Registered User

    Oct 2, 2017
    405
    23
    18
    Male
    Retired electronics engineer
    Chichester
    Country Flag:
    Region Flag:
    I know I won't be popular with the real clockwork lovers but this Kundo is clever. It does entirely mimic the genuine thing AND it has a balance wheel which makes it much more rugged and accurate. From a reliability point of view these must have come as a relief to the warranty. Can anyone put a date on their introduction? Electronic balance but not quartz. Driven by AA cell. How long will it last?
     
  29. Tashepp

    Tashepp Registered User

    Nov 16, 2014
    6
    0
    1
    Country Flag:
    Hi Cheesehead,

    I’m looking for this exact suspension spring but am running into dead ends everywhere. Do you know the diameter of the wire and size of the blocks so i can make one that screws together? Or do you know where to buy one?
    Thanx in advance, Tim
     
  30. KurtinSA

    KurtinSA Registered User
    NAWCC Member

    Nov 24, 2014
    3,140
    96
    48
    Aerospace Engineer (Ret.)
    San Antonio, TX
    Country Flag:
    Region Flag:
    Tim -

    I have a different kind of quartz clock and I managed to find a replacement spring of sorts; posted here:

    Kundo - Kundo Clock Missing Parts

    As a point of reference, the spring thickness appears to be 0.0026 or 0.0027".

    Kurt
     
  31. Tashepp

    Tashepp Registered User

    Nov 16, 2014
    6
    0
    1
    Country Flag:
    Ok thanx,

    Tim
     

Share This Page