How to tune a bell ?
I'm building a doorbell-operated carillon of bells, which will play the "Westminster Chimes" on a set of real brass bells (the sort with a wooden handle that you would normally shake). They will be hammered either by solenoid mechanisms, or by mechanical triggers, driven from a pinned rotating drum. My question is - Is it possible to change the pitch of a bell, either by removing metal, or adding metal (with a weld), without ruining the resonance or the tone of the bell ? - And upon what part of the bell would you perform this action ?
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From what I've read, bell tuning is an ancient and complex craft. The slightest addition or removal of a small amount of metal can dramatically change the overtones and the sound of the bell. Computer simulation of the resonances helps nowadays, but it's still somewhat of an art rather than a science.
Have you seen THIS Instructable? It uses a cheap octave set of bells, but you may be looking for a higher quality product.
Have you seen THIS Instructable? It uses a cheap octave set of bells, but you may be looking for a higher quality product.
May 10, 2009. 2:26 AMand7barton (author)
says:
If I were to carefully grind away at the rim of the bell, I imagine this would successfully RAISE the pitch....... The main problem is - If I have a bell that needs to be LOWERED in pitch, what's the best way to go about it ? I'm very unlikelt to find bells that are already in the pitches I require. For Westminster Chimes I'll need four bells.
HERE it says the notes are A B D G which must be pretty standard. Handbells don't appear to be widely available so it might be an idea to contact a local ringers group to find where they get theirs from.
Looking at prices from the main manufacturers, it's going to be a VERY expensive mistake if grinding or welding doesn't have the effect you want.
Looking at prices from the main manufacturers, it's going to be a VERY expensive mistake if grinding or welding doesn't have the effect you want.
May 11, 2009. 12:00 AMand7barton (author)
says:
There are loads of traditional-style bells on Ebay. I already have a couple of the four I need. They are all in the region of 6 inch diameter. I'll worry about tuning them when I have the full set. I have an electronic tuner. I guess I can only sharpen them (flattening them seems to be questionable if we want to preserve the tonal and resonance character of the sound), so I'll work out how much to sharpen them when I know which of the bells is the lowest pitched. I've decided, the pinned barrel will lift pivoted hammers and then release them to hit the bell. After hitting the bell, the hammer will fall back to its original position close to, but not touching the bell rim.
For some strange reason I didn't look at eBay - I normally would. Interesting project. I hope you're going to post and Instructable when you're done.
May 10, 2009. 9:29 AMorksecurity
says:
The easiest kinds of bell to tune are solid rods (which are what most "grandfather clocks" use), flats (which are what most doorbells use), or tubes (which are what most wind chimes use). Those are all relatively simple shapes and can be ground roughly to tune fairly easily. Where you strike them: Depends on what overtones you want. The goal is to get the bar to resonate. That resonance may be one wave across the whole bar (strike the center), half the bar (strike 1/4 from an end) 1/3, and so on.
May 10, 2009. 11:55 PMand7barton (author)
says:
I already have some of the bells - They are standard-shaped brass bells (at the moment, they have a turned wooden handle on them) - They are good and loud and I like the timbre - I don't want just another set of the usual tubular bells like everyone else has.
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