Machining a bell for better tone

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NP317
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Re: Machining a bell for better tone

Post by NP317 »

In 1980 and 1981 several of us restored two geared locomotives to start the Mt. Rainier Scenic Railroad in Mineral, Washington, USA.
The #91 3-truck Heisler (former Kinzua Pines # 102?) was restored first and its original bell had a nice reverberating clear tone that carried a long distance.
The second locomotive was Climax #10, former Hillcrest Lumber on Vancouver Island, BC, Canada. eh...
#10's bell was very clunky with little ring and more THUD. Given that Climax locomotives were considered the "poor man's locomotive", and other aspects of its design and fabrication backed up that idea, that bell fit right in. Worth listening to.
I got to hear each of those bells from the cab for several thousand miles, and remember them well.

And the Heisler was totally my favorite geared locomotive to engineer.
RussN
bells
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Re: Machining a bell for better tone

Post by bells »

Hi folks,
I stumbled on this site a few days ago and saw this thread, A dead or dull bell will never be any thing but a dead or dull. Yes you machine a bell to change the note/tune but you generally can only tune a bell down in Hertz. below is a video of a few minutes of me tuning a bell. https://youtu.be/Cko4bEzH7LU
Glenn Brooks
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Re: Machining a bell for better tone

Post by Glenn Brooks »

Bells, Welcome to the forum! And thanks for the info and link. Very interesting. Indeed, after a good deal of research, i concluded the bronze formulation for my poor bell was improper. The old masters think proper bell metallurgy would have a higher tin content than other forms of bronze. Apparently the proper amount of tin gives bells their distinctive ring - along with the mysteries of properly shaping the various levels of the bell casing. I finally concluded, my poor bell is probably hopeless - destined to sit on a shelf and just clunk and thunk when asked to sign a song.

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Howard Gorin
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Re: Machining a bell for better tone

Post by Howard Gorin »

Your bell my be cast in something other than Bell Bronze. Bell Bronze is 80% copper, 20% tin, absolutely no lead. No amount of tuning can improve
the sound if the bell is cast in most commercial alloys.
Bell Bronze is expensive and brittle. I want to cast some more 1.5" scale bells, When I contact a ingot maker for an ingot of bell bronze, the ingot
maker advises me the they will not make less then 2,000 pounds of Bell Bronze. Just one more misstep in my life.
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Harold_V
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Re: Machining a bell for better tone

Post by Harold_V »

Howard Gorin wrote: Mon Jun 14, 2021 1:31 pm the ingot maker advises me the they will not make less then 2,000 pounds of Bell Bronze. Just one more misstep in my life.
Alternately, seems to me you could do your own alloying. Both of the constituents should be readily available, especially copper.
A source for exceptional quality (high purity) copper is wire. It is electrolytic pure copper, and, I suspect, that copper plumbing pipe and tubing (the thin wall stuff) is also pure copper. One would want to avoid any solder connections, however.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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gwrdriver
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Re: Machining a bell for better tone

Post by gwrdriver »

Howard Gorin wrote: Mon Jun 14, 2021 1:31 pmJust one more misstep in my life.
I don't think of it as a mis-step. It's probably one of two things . . .

It's not economically viable for him to make up alloy in a batch of less than 2k/lbs, or
He just wants you to go away and not bother him.

I was once told to go away and not come back (at a foundry) simply because I KNEW someone who in the past had made an insufferable pest of himself. How did they know I knew him and would probably be just as much of a pest? I brought in one of his patterns to have a casting poured, which made me guilty by association! :lol:

I don't blame them though . . . he was indeed an insufferable pest.
GWRdriver
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Howard Gorin
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Re: Machining a bell for better tone

Post by Howard Gorin »

I was talking to the foundry that does my sand casting. I mentioned the problem obtaining bell bronze, no problem! That foundry is pouring bell bronze for some other application. The sand cast foundry is not allowed to remelt risers and gates used to cast the bell bronze parts. I take the risers and gates to the foundry that does my investment casting and they will pour my bells.
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Dick_Morris
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Re: Machining a bell for better tone

Post by Dick_Morris »

I've read that the quality of a whistle's tone can also be affected by the material the bell is made from. Steel will sound different from bronze.
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gwrdriver
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Re: Machining a bell for better tone

Post by gwrdriver »

That's certainly the case . . . after all, both are musical instruments.
GWRdriver
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LVRR2095
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Re: Machining a bell for better tone

Post by LVRR2095 »

Dick_Morris wrote: Tue Jun 15, 2021 1:07 am I've read that the quality of a whistle's tone can also be affected by the material the bell is made from. Steel will sound different from bronze.
You are basically talking a high pressure organ pipe.

Keith
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Re: Machining a bell for better tone

Post by bells »

I make bronze bells, 80% copper 20% tin. I use loam mud, horse hair and manure to make the moulds, I have made bells from 1kg to 23kgs, and as I type I have 2 moulds under way that will be the biggest i have tried and these bells will nudge 50 kgs each.
I tune my bells using a hertz app? I do small bells in the lathe and the larger ones I use a 40 grit flap disc grinder and methodically rotate the bell as I grind. Bells will never resonate properly if the casting is porous, or the metal is too soft due to to much copper or contaminants. 80/20 and you want to be within a few percent.
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