• The Bulletins and Marts are again available online. The network connectivity problem has been fixed. Thank you all very much for your patience.

Making music with clock gongs?

Chris Phoenix

Registered User
Oct 22, 2021
5
0
1
50
Country
I want to build a musical instrument just for fun, putting clock gongs above a manual typewriter and using the type bars as hammers so I can type music. I bought a few $1.75 coil gongs to experiment with and learned how much I don't know.

I learned I'm going to need a sounding board. I tried clipping the coil to tune it, and it changed the sound a lot. I'll want a bit over an octave, tuned accurately by half-tones, which implies the frequency will vary by almost 3X for about 18 gongs, and I'll probably have to make or at least tune my own.

I think maybe I want rod rather than coil gongs, but not if they're too thick - there's only a fraction of an inch between the type bars. It would be fine to have rods two feet long; the instrument doesn't have to be portable or cased.

I can make my own gongs if I know how. I've seen people making clock gongs out of piano wire - is there a better choice for an adequate gong?

I can experiment and learn a lot on my own - I can read articles on gong theory (but I couldn't find any) - any hints, advice, or references will be most helpful.

Many thanks!
 

Willie X

Registered User
Feb 9, 2008
15,263
1,945
113
Did you know that you can buy a nice baby grand for 50 bucks, or less? Willie X
 

J. A. Olson

NAWCC Member
Dec 21, 2006
4,762
574
113
WI
Country
Region
Japanese school bell chimes already play music on rod gongs in the manner you describe. Most play Westminster but some were tricked out to play different tunes such as Bluebells of Scotland:


Coil gongs are prone to going out of tune with temperature fluctuations and are not ideal for a fine-tuned instrument.
 

Chris Phoenix

Registered User
Oct 22, 2021
5
0
1
50
Country
Japanese school bell chimes already play music on rod gongs in the manner you describe. ....

Coil gongs are prone to going out of tune with temperature fluctuations and are not ideal for a fine-tuned instrument.
That video is great, and reassures me that I'm on the right track. Many thanks! (Also, I'll definitely try to rig up the shift key to a damper.)

Questions about rod gongs:
- Too thick? 6.5 mm > 1/4" and I think there are more than 4 type bars per inch (I found a beautiful typewriter but it hasn't arrived yet).
- Remountable? I'll definitely need to make my own mount for them. I've only found gongs already mounted - do they unscrew without damage?
- Tuneable far enough? Can I whack off several inches and still keep a good tone?
- Price range for a decent-sounding instrument (like in the video)? Is $5 a gong reasonable?

Do the coil gongs return to tune when the temperature returns to normal, or does it detune them permanently? I don't mind re-tuning a couple of times, or gently heating and cooling them a few times (analogous to pre-shrinking cloth?) if that will help.

Theory questions (feel free to ignore, point me at references, or tell me to go ask a luthier):
- What direction do coil gongs vibrate in? (what are the possible relationships between hammer angle, coil plane, and sounding board?)
- Why does the pitch of a coil gong change if I straighten them or pull them into a 3D corkscrew? (This is why I started with $1.75 gongs, Willie!)
- For either gong type: What are the design rules for the mount? I'm guessing: Non-damping and non-resonating (hence, very stiff), and preferably several times as massive as the gong to slow the energy transfer and sustain the sound? Where should the center of mass be?
- What about design rules for the sounding board, and where to attach the mount to the sounding board?
- With several gongs on the same mount, do we get a tandem-pendulum type of energy transfer, how does that affect the sound (I'm guessing overtones get stronger and weaker with a beat of several Hz), and can/should it be reduced?

Again thanks for whatever help you have time to give!
 

J. A. Olson

NAWCC Member
Dec 21, 2006
4,762
574
113
WI
Country
Region
Rod Gongs:

Thicker diameter (3.6 MM or 4 MM) will give a sharper blow and quieter hum at shorter lengths, louder sound at longer lengths.
Steel rods fare better at longer lengths for lower notes.

Thinner diameter (2.5 MM or 3 MM) gives a quieter blow and louder hum at most lengths. Quieter at longest lengths.
Copper and bronze rods are ideal for higher pitched notes.

Rods with a longer tapered neck will vibrate more profusely than rods with a shorter neck. There must be some form of taper so the rod produces an acceptable range of non-harmonic frequencies and resonates effectively.

Rods vibrate in an outward pattern not unlike an organ reed. The smoothness or roughness of the rod's end affects how loud and clear the sound will be.

It must be noted the non-harmonic frequencies in rods shift as they get higher or lower pitched.


The shape of the hammer has some effect with round hammers giving a sharper blow, square hammers giving a duller blow.
I don't have the specs for the schoolhouse chime in that video but it used thick steel rods. The rods' sound is then transmitted into an electric speaker and played over intercom or outdoor speakers. This is an effective way to make the sound much louder.

The shape of the captive block also affects sound: a larger bank will give a deeper voice, while a smaller bank results in a tinnier voice. Making some replication of the Japanese schoolbell chime would be the most effective way to make an instrument using rod gongs. They were made for public service and leftover examples may appear on auction - in Japan! They never found any service in the United States.

In the USA there are Schulmerich Carillonic "bells" which comprise of a flat gong rod hooked up to an amplifier. The sound on its own is quite dull but when amplified can create a more convincing "church bells" sound. The one and only drawback was excess echo from the amplified sound bouncing off surrounding buildings:




Coil Gongs:

Shape, length, and coil curvature all affect the sound in one form or another. Flat rectangular coils give a mellower sound while sharp square coils give a shrill sound. Round wires are not normally used for tuned coil gong sets and are left to give a non-harmonic 'Big Ben' sound.


The pitch going in/out of tune with temperature fluctuations cannot be effectively controlled. It is more useful if one wants a "Big Ben" sound where the bells are perpetually off-key at all times. Coils vibrate inward and is one factor into their low, burly sound. The coil gongs found on most chime clocks are attached to a pedestal which vibrates like a tuning fork. One setback into using coils as an instrument would be to mount them on a pedestal large enough to sustain several coils without killing their resonance. The best usage for coil gongs as an instrument would be with fewer coils - in example: Parsifal bells which require just 4 'bells'.


Tuned coil gongs have not been made as spare parts for over 100 years now.

At some point I really want to compile these observations and useful repair tips into a NAWCC document but there's still more to finish up in research and it depends on what the administrative heads think. Stunning as it seems, chime clocks don't get a lot of historical representation.
 
  • Like
Reactions: JimmyOz

Chris Phoenix

Registered User
Oct 22, 2021
5
0
1
50
Country
The shape of the captive block also affects sound: a larger bank will give a deeper voice, while a smaller bank results in a tinnier voice. Making some replication of the Japanese schoolbell chime would be the most effective way to make an instrument using rod gongs. They were made for public service and leftover examples may appear on auction - in Japan! They never found any service in the United States.
....
Tuned coil gongs have not been made as spare parts for over 100 years now.
I'm sure you're right that a Japanese chime is a better design. But I must have a typewriter! And no electronics, just a mechanical soundboard / diaphragm / horn. I've been fortunate to hear a wax-cylinder phonograph (I think it was even an Edison model) - the sound quality and loudness were startling. And I've always felt that bass guitars were cheating - turn off the amp and they sound like rubber bands.

You said a coil gong vibrates inward - you mean the motion is to coil and uncoil the spring? I begin to see why it's kind of hopeless to get a good musical tone out of such things! The angular momentum would vary all along the length of the coil, and the spring force would be constant-ish - it would be whipping all over the place, not remotely cyclical!

It's very useful to know rod gongs come in smaller diameters - thanks. It sounds like rod gongs can be thin enough to stack across the typewriter.

FWIW I gripped my cheap coil wire in vice grips, touched the vice grips to a bookshelf, hit the coil with a crochet hook with a rubber band stretched around it, and got a sound I liked. So I'll pursue my Quixotic dream - but probably with rod gongs - you've convinced me of that much. I'll get a few and experiment.
 

Chris Phoenix

Registered User
Oct 22, 2021
5
0
1
50
Country
Re hammer shape - I read somewhere that a hammer which touches more of the rod will damp more of the really high overtones.

BTW sorry if I seemed to be "yelling" about the typewriter. Getting tone right in text is harder than in coil gongs!
 

Isaac

Registered User
Aug 5, 2013
1,197
308
83
Country
Region
To add a last bit of info to CCF's post,

Some companies (Junghans most notably did this) used both coiled gongs and chime rods in their clocks - namely, the coiled gongs to deal with striking and the rod gongs to deal with the chiming portion. I find these setups to be quite interesting, and the contrast between the two sounds is really something else.

Below is a video of an old Junghans with 16 chime rods (4 rods of very similar length are struck for each note, so 16 rods total make up the Westminster melody) and 2 coiled gongs (same as the Junghans Kaisergong in the video CCF shared). Junghans also produced a few mantle clocks with a similar configuration.


Regards.
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
47,827
2,290
113
North Carolina
Country
Region
For the small spaces you need, I think strings would be your best bet. They can be tuned fairly easily.
 

Chris Phoenix

Registered User
Oct 22, 2021
5
0
1
50
Country
For the small spaces you need, I think strings would be your best bet. They can be tuned fairly easily.
It's a good thought, and I'll come back to it if I can't make gongs work. But a dozen or more strings - I'd basically be building a harp at that point, and that's beyond my skills and tools. Gongs only have to be fastened at one end, and don't need to be held in tension.
 

Forum statistics

Threads
169,773
Messages
1,481,794
Members
49,157
Latest member
DavidEckman
Encyclopedia Pages
1,060
Total wiki contributions
2,965
Last update
-