Strike the Gong

Discussion in 'General Clock Discussions' started by gleber, Aug 15, 2019.

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

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    Is there an ideal place to strike a typical gong (coiled or straight)?

    Also, sometimes the gong sounds nice, and others, clangy or dull during the same strike cycle. I think it depends on the point of vibration when the hammer hits. Is there any way to ensure it sounds consistently nice?

    Thanks,
    Tom
     
  2. Isaac

    Isaac Registered User

    Aug 5, 2013
    562
    64
    28
    Male
    Student
    Country Flag:
    Region Flag:
    Usually the straight area right before the coiled gong starts to coil is the sweet spot in terms of sound. Make sure the hammer is hitting the coil straight on.

    Some gongs are just built cheaper than others, and will sound pretty bad no matter what you do to them (I'm looking at you, kitchen clock wire gongs)
     
  3. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    Yes, certainly some gongs are much better than others, but my question is some strikes on the same gong are much better than others - what causes this and can it be controlled?

    Tom
     
  4. Uhralt

    Uhralt Registered User
    NAWCC Member

    Sep 4, 2008
    3,494
    311
    83
    Country Flag:
    Region Flag:
    I think this is related to the fact that the gong is still vibrating (causing it to slightly move) when the next strike hits. So the distance between hammer and coil is not consistent. You will find that the first strike usually sounds fine and then mixed results follow. You can minimize the effect by finding a spot for the hammer to strike where the gong moves least and by slightly increasing the distance between gong and hammer. Slowing down the strike also helps.

    In my experience it is not always possible to make the effect go away completely, you can only minimize. BTW, the same effect is true for bells, too.

    Uhralt
     
  5. chimeclockfan

    chimeclockfan Registered User
    NAWCC Member

    Dec 21, 2006
    3,767
    119
    63
    Chime clock & gong studies.
    WI
    Country Flag:
    Region Flag:
    On gong rods the hammer is usually positioned right before or after where the tapered neck begins. Most ideal sound quality is achieved and the rod won't whip around excessively when struck.

    The consistency of hammer blow is more dependent on the hammer design rather than the type of gong. I think the most stunning example of hammers for gong chimes would be this 'Peerless' M. Bäuerle weight driven clock with adjustable tension springs on each chime hammer.

    peer10.jpg
     
  6. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    I agree with the distance, but I think it is more that the hammer will either be in phase with the vibration, or out of phase, which will change the tone.

    The minimal vibration amplitude will be at the base or mounting point of the gong, but I don't think it works well when hit there. That is the reason I asked about ideal spot to strike.

    I think I understand the general physics, but was mainly wondering if anyone has studied this in detail or has any recommendations based on the study or at least empirical evidence. Isaac - is there any logic or consensus behind your recommendation?

    Tom
     
  7. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    Thanks for the added info Chimeclockfan. It is interesting to see the effort different manufacturers went through to optimize (or claim) superior quality.

    On coiled gongs where the hammer strike spot seems to be further from the block than on straight gongs, I think the location does lead to more "sour" notes. In the coiled gong, the spot is farther from the block and movement at that spot is larger and I think it would be very difficult to synchronize the strike with the phase and position of the gong. And, then you would have to account for different speeds when the spring is wound or loose (not an issue for weight driven), and how clean the clock is. Both of these would affect the speed of the train and the ability to snyc with the gong frequency.

    I'm also sure the hammer tip material and its condition, hammer weight, spring tension, etc. have a significant effect, but I'm trying to focus on a specific (but undefined) gong / hammer and how to optimize it's performance (assuming these other factors like hammer tip condition are in good shape).

    Tom
     
  8. upstateny

    upstateny Registered User

    Oct 2, 2015
    496
    19
    18
    Country Flag:
    Tom, I have had a similar problem with a Waltham coiled gong. Which I suspect is what you are working on. I found:

    Waltham coiled gongs are attached to a large brass block which is threaded onto a long post which is attached to a base bolted to the back board.

    Make sure that the block is attached firmly to the post.

    The hammer distance can be adjusted in tro ways 1)by adjusting the heighth of the post 2)by sliding the hammer along the hammer rod.

    Some Walthams use a hammer with a non-removable metal striking surface and others have with a removable round leather end. The length the leather projects from the hammer will exacerbate the problem, usually on every other strike.

    I have found that how hard the leather is will also give you a headche.

    I agree that the flat portion of the gong closest yo the top will provide the best sound. Gongs on the Walthams I have worked on have about a 1 inch sweet spot.

    I will send you a PM with a phone # you can call to discuss.

    Tim
     
  9. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    I apologize if this is a little off topic. Here's a clock gong situation.
    This Scottish bracket clock doesn't strike the "sweet spot" consistently, except for the first strike. The clock has a slow strike, but the hammer hits the gong so hard, the entire gong visibly vibrates maybe about 1/2-3/4". So, sometimes the gong is vibrating so much, the hammer may not hit it straight on for the rest of the striking sequence. Many times, at the end of the last strike, the gong bounces up and reverberates on the hammer (which my wife doesn't like).
    The clock strikes so hard, a replaced piece of glass on a side panel loosens and vibrates against the case (again the wife doesn't seem to like). Can't seem to get the glass to stay tight. It's loose now after a few years when I last tightened it. If anything is resting close to the clock on the table top, that may vibrate, too.

    Jas. Muirhead Glasgow 001.JPG Jas. Muirhead Glasgow 005.JPG
     
  10. rmarkowitz1_cee4a1

    rmarkowitz1_cee4a1 Registered User
    NAWCC Member

    Nov 26, 2009
    4,626
    536
    113
    Country Flag:
    This all reminds me of that T Rex song.

    bang-a-gong-and-get-it-on.jpg-e1456960145793.png

    And CR thought he was off topic?

    RM
     
  11. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    Thanks for the interest. My question is generic, not specific to any clock. My recent Waltham has a single tube for the strike and it sounds nicely normal. I have several other clocks with gongs and some are good, some not so good. I just want to learn how to optimize the set up to get the best quality sound they have to offer.

    Tom
     
  12. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    If I didn't know you were in PA, I would think your neighbors might suspect earthquakes.:D

    Is there no way to reduce the spring tension on the hammer?

    Tom
     
  13. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    Ha, I missed an opportunity for a catchy thread title.

    Tom
     
  14. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    5,784
    316
    83
    Male
    Retired, not tired
    Country Flag:
    Region Flag:
    Is there any room to place small amounts of clear silicone caulk at various points around the glass, perhaps from inside the case? I know, use of modern materials on an antique clock is not canon, but if small amounts are used (recommended) it is easily reversible. Depending upon the space available, perhaps you could use something more period appropriate to isolate the glass and dampen the vibration.

    It sounds to me like you'll just have to tune each clock as you might tune an instrument. Each one is unique. Rules of thumb may give you a good starting point, but you'll have to listen to assess what's going on and take steps to improve the sound to your ear. Chances are pretty good that by the time an Antique crosses our bench, the hammer(s) have been "adjusted" many times already.
     
  15. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    Yes, I was trying not to use modern materials, and keep it reversible. Because the replacement glass isn't the exact fit, I put a small shim between the glass and the oak small molding strips inside the case. The molding strips are fastened with small wire nails, and I added a small amount of glue. That lasted a couple years. I will look at it again, maybe I can use silicone as a "shim", not to seal the glass in place so it is reversible.

    It's just funny with this clock, how strong the vibration is. I think it would be considered a 3/4 size case, but the movement is full size. I didn't realize how much vibrating occurred with the gong until I saw it striking inside the case. Quite a lot of activity. The sound is like a tower clock similar to Big Ben in the distance (at least when it hits square on).
     
  16. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    With a description like that, you need to share a video.

    Therein lies the rub, and the reason why I started this thread, but I'm beginning to think we're destined to live with clangy gongs unless they are so slow that the vibration dies out before the next strike. I do prefer a slower rate - sounds more like a church bell.

    Tom
     
  17. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    5,784
    316
    83
    Male
    Retired, not tired
    Country Flag:
    Region Flag:
    I'm sure you'll come up with a good solution to the problem. Good luck and please share your solution with us if you have the time and inclination to do so.
    Maybe there are some approaches in the archives which may give you ideas or perhaps someone else will see this thread and weigh in.

    There is a solution Tom. You can make your own clock with dampening in addition to normal striking as Dave Weisbart did:

    Other than that, I suppose we just have to tune and perhaps try different hammer insert material. Maybe try to slow the strike down while leaving enough power to run the train for the full design run time between windings... Please let us know how you solve the problem.
     
  18. Arthur Cagle

    Arthur Cagle Registered User

    May 22, 2003
    407
    5
    18
    Male
    Retired
    Greater Baton Rouge Area, Louisiana
    Country Flag:
    Region Flag:
    Tom, all of the above comments being true enough, adding a soft piece of leather to the hammer should lessen the vibrations of the gong, therefore the duration of the vibrations, so subsequent strikes may hit a vibration free coil. You may rename me "Captain Obvious," if you wish, as you no doubt thought of this. Or perhaps I'm wrong...wouldn't be the first time!
     
  19. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    Thanks Bruce - that video was the kind of information I was looking for - a little on the scientific side. I tried damping the gong with my finger after each strike. It sounds terrible, I think because we are used to hearing a gong or bell resonate for a while. When it stops abruptly, it just doesn't sound right. Perhaps if it could be timed better than manually, more like in the video, and stop just before the next strike, it may sound a little better.

    Thanks Arthur - The main clock of my experiments (but not the only reason I asked this question) has a leather tip, but it could probably be replaced with newer softer one and I agree with you, it might sound better for single notes (1 and 1/2 hours) and sequential strikes.

    Tom
     
  20. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:


    Here is James Muirhead of Glasgow striking 11:00. Keep watching until after 6 or so, the wire becomes increasingly active. The hammer head still has it's original tip of what appears to be hardened leather. It's winding day today, so the spring is getting relaxed, although the fusee keeps it strong. After I wind, the strike is slightly faster for approx. 12 hours.
     
  21. Isaac

    Isaac Registered User

    Aug 5, 2013
    562
    64
    28
    Male
    Student
    Country Flag:
    Region Flag:
    Wow, that's quite some movement. Interesting that the gong block itself doesn't move much.
     
  22. gleber

    gleber Registered User

    Jun 15, 2015
    1,429
    140
    63
    Male
    Underwater Robotics Expert
    Downingtown, Pennsylvania USA
    Country Flag:
    Region Flag:
    That's a massive hammer! I get vertigo just watching that gong vibrate.:eek:o_O:confused:

    Tom
     
  23. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    I exaggerated, the range of vibration is more like 1/4-1/2". Mostly on the inner coil. I could have sworn the top of the gong moved more. I know sometimes the top moves more, you can hear it reverberate on the hammer head.
     
  24. Arthur Cagle

    Arthur Cagle Registered User

    May 22, 2003
    407
    5
    18
    Male
    Retired
    Greater Baton Rouge Area, Louisiana
    Country Flag:
    Region Flag:
    Odd, but to me the seventh strike seems to have more clarity than all but the first strike. Anyone else get this?
     
  25. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    I had this clock out of the case today to oil the movement. I stuffed 2 small pieces of leather between the loose glass and the oak molding that held the original glass. I cut the small leather pieces slightly thicker than the shim, and pushed the leather in place with a small screwdriver. Sounds like it worked. The gong is slightly more subdued.
     
  26. D.th.munroe

    D.th.munroe Registered User

    Feb 15, 2018
    283
    66
    28
    Male
    Full time clock and watchmaker
    BC Canada
    Country Flag:
    Region Flag:
    Hi Chris
    I would try moving that hammer further out on the rod if you can, to hit closer to the base of the gong more on the flat spot, it should settle vibrations down, I usually find the "sweet spot" roughly about 1/3rd of the way in from the start of the bend to the base of the gong.
     
  27. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    That's advice that didn't occur to me. I have other gong striking clocks. And many have the hammer tip in the position you describe. But this one, I don't think it was ever serviced before me. At least not for a very long time. The hammer looks like it is where it's been since the clock was born. The original hardened felt (or dried leather?) is still on the hammer tip. So it never occurred to me to move the hammer.
    The vibration doesn't bother me. I just thought it's funny how the gong is sort of causing the case to blow apart slowly. Kind of like self-destructive behavior. And the loose bits of the case made the strike sound "off".
     
  28. novicetimekeeper

    novicetimekeeper Registered User

    Jul 26, 2015
    8,865
    408
    83
    Male
    retired and on my second career
    Dorset
    Country Flag:
    Region Flag:
    Never thought about it much before, I hate gongs with a passion, but the thing must be designed to have a standing wave in order to resonate, which means that you want to hit it on a node so that the part you hit is virtually stationary. The nodes will be spread evenly around the coil but the ones on the straight part near the mount must be the easiest to set up for. The first fixed point is the block, the next node half a wavelength away from that point.
     
    D.th.munroe and gleber like this.
  29. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    That's OK, not everybody likes Little James at first. But he's been a good buddy for several years. He's Scottish, and has his little quirks. For example, his escape wheel looks like a dead beat, but he doesn't have maintaining power. Maybe 1 or 2 times a year, he stops completely when he's being wound. But most often he only stops when his key is being turned. Whenever we have visitors, James is a conversation starter. When we first adopted James, he was sad, and neglected. But we raised him, and now he's a fine little clock. Just had his movement out yesterday, he's a nice, robust, strong, and accurate fellow. It's been a good experience to have Little James as a member of the household. :love:
     
  30. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    40,186
    614
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    I think the hammer is resting on the gong a bit before raising again. If you raise it a little (slight bend) it will sound clean on every strike.
     
  31. Willie X

    Willie X Registered User

    Feb 9, 2008
    11,598
    582
    113
    What D.th and bugs said + the hammer lift needs to be decreased to about half what it is now.

    So, it has three problems that should be easy to correct. These 'fixes' might not apply to Tom's clock. But I would say that probably more than half of the older German clocks out there have worn areas that (over time) produces excesive hammer lift.

    Willie X
     
  32. JTD

    JTD Registered User

    Sep 27, 2005
    6,509
    318
    83
    Well, I like Little James very much, both his case and his innards. Glad he found a good home where he is loved and cared for.

    JTD
     
  33. JimmyOz

    JimmyOz Registered User

    Feb 21, 2008
    136
    14
    18
    Male
    Country Flag:
    Region Flag:
    I was going to suggest that you use a little bit of brown felt in the recess so that the glass does not touch any of the timber, that would stop any vibrations and would be something that would not look out of place on an old clock.

    Funny enough I am a wee Jimmy from Edinburgh, however now live in Australia, it's a weather thing....
     
  34. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    I really think James Muirhead strikes the way he was intended to. The gong is large, soft, and flexible. It's supposed to vibrate.
     
  35. Willie X

    Willie X Registered User

    Feb 9, 2008
    11,598
    582
    113
    I would say not. But, if you like it, that's just fine too.

    Lots of people get used to a clock's sound, even though it's obviously abnormal. The ole repair person best leave it alone until they ask the owner about it.

    Willie X
     
  36. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    OK, I moved the hammer up the rod. That's how you adjust the hammer, move it up the rod...since it's a steel rod, you can't bend it like a brass wire. Now the hammer sits about 1/4" off the gong. The hammer was almost touching the gong earlier.
    It doesn't sound too much different to me. It's a Scottish Victorian gong striking clock.
     
  37. JimmyOz

    JimmyOz Registered User

    Feb 21, 2008
    136
    14
    18
    Male
    Country Flag:
    Region Flag:
    The glass would not have been a tight fit when original, however the recess and beads would have been square to hold it from moving, years of weather, moisture, heat, expansion, contraction and taking the beads off is why it is now vibrating, I think a very nice clock like this (Gothic Revival) deserves better than a bit of leather pushed in to stop that, which is a temporary fix. Just my view.
     
  38. JimmyOz

    JimmyOz Registered User

    Feb 21, 2008
    136
    14
    18
    Male
    Country Flag:
    Region Flag:
    It seems there is a few strikes that have a double hit, lift the hammer a few mm and it would stop that and sound a lot better.
     
  39. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    40,186
    614
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    Yes, it's improved, but still rattling a little. Raise it a bit more. Also, the hammer seems to be raising a bit after the last strike. It should remain fully down. That can be adjusted with the gathering pallet.
     
  40. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    Lol, the sound of the gong didn't change dramatically with the adjustment, but there is less vibration and reverberation now. I think it's funny that I never considered adjusting the hammer on this Scottish clock before. I have German gong strikers that almost instinctively invite adjustment of the strike. Of course we know the Germans worked hard to get their gongs to sound "perfect". The Scottish clock has a different philosophy than the German gong clocks we know so well. The hammer on the Muirhead is larger, and is meant to be struck with considerable force on the gong. The gong itself has an extra coil, and is large in size. The later German gongs are made of harder steel, and the coils usually are more abbreviated. And they aren't struck with as much force. I don't think the hammer is rising at the end of the strike, I think you see my unsteady hand. At least not enough for me to need to adjust any further. I think there is rattling of a candle holder on top of the cupboard next to where the clock sits.

    The Muirhead can be dated probably somewhere in the 1850s. In 1860 He became Muirhead and Son. Big Ben began his run in 1859, which supposedly raised the popularity of the gong striking household clocks. It is interesting to compare this Victorian "bracket" clock, to the later German ones which are more plentiful. So thanks for the advice.
     
  41. bruce linde

    bruce linde Technical Admin
    NAWCC Member

    Nov 13, 2011
    5,341
    454
    83
    oakland, ca.
    Country Flag:
    Region Flag:

    agreed... i can hear the hammer getting muted by the slightly looser area of the coil it's currently hitting... too much spring in the coil at that point. make it hit more to the left and see what happens.
     
  42. Chris Radano

    Chris Radano Registered User

    Feb 18, 2004
    3,362
    133
    63
    Male
    Pennsylvania
    Country Flag:
    Region Flag:
    You guys have great hearing. I think it sounds alright. Maybe I'm deaf. What?
     
    gleber likes this.
  43. JimmyOz

    JimmyOz Registered User

    Feb 21, 2008
    136
    14
    18
    Male
    Country Flag:
    Region Flag:
    CAN YOU SPEAK UP I MISSED THAT.
     
  44. novicetimekeeper

    novicetimekeeper Registered User

    Jul 26, 2015
    8,865
    408
    83
    Male
    retired and on my second career
    Dorset
    Country Flag:
    Region Flag:
    If you have a hearing problem like I do, you get rather bored of that response when you tell people. They all think they are being original and funny.
     

Share This Page