Retuning orchestra chimes - (Discussions with Marty Akerman)
-----Original Message----- From: Marty Akerman Sent: Monday, 10 November 2003 4:21 PM To: email@example.com Subject: Retuning orchestra chimesHello Jim,
I have a couple of questions you may be able to help me with. I build and repair marimbas, and lately I've been volunteering with a group that refurbishes old pipe organs. I've been asked to retune several percussive stops that are essentially air actuated marimbas. No problem there, as I am quite familiar with tuning the bars and resonators.
This week though, I was given a set of orchestra chimes, or tubular bells that need to be retuned, and I have no actual experience working with them. These were built by the Deagan company back in the 1920's when the pitch standard was A=435. I need to bring them up to A=400. I had imagined that they were just an open tube, and raising the pitch would just involve shortening them a bit. However, they are actually stopped at both ends.
Do you know if I need to move the lower end stopper a little to retune it, and if so, how much? Is there a formula I can use to estimate the stoppered length? Do I need to move the stopper, and also take a little mass off one end of the tube?
Do you know if orchestra chimes are actually tuned a little sharp? I know some percussive instruments are actually tuned to A=442 to give them a slightly brighter sound.
Also, these chimes are pretty beat up and some of them are cracked around the stoppers. The cracked ones sound completely dead. Do you know if welding up the crack would restore the tone?
Any advice you could give would be greatly appreciated, or if you knew of another resource you could refer me to, that would be wonderful.
MAKE AND TUNE YOUR OWN WINDCHIMES!
I would be really interested to know how you get on with these tubular bells actually. They really can be full of surprises when it comes to the mechanics of their sound production as you have already started to discover. I'm afraid I'm really not that knowledgeable about these kind of tubes so I probably can't help you a great deal. Are the stoppers fully sealed or ones with little holes in the top as most of them are? I SUSPECT (suspect only) that the stops tend to cut down the upper harmonics produced and lessen the length of tubed required a little as opposed to open on one end) Seems to me that a solid end tends to force a nodal position along the tube and also pretty much prevent any modes that move around the tube as the cross section cannot flex much. I did have one guy email me once with some links which you may or may not find helpful - worth a look though from a maths point of view. They are:
I suspect that to do a proper note change you would have to take stop off cut and put stop back on - HOWEVER I think in this case it probably won't be needed - in fact the metal ground to dust in the action of cutting would probably already be too much to raise the pitch by the amount you are talking about. We are talking about 5 to 7 cents worth of pitch here so really at the very edge of what the average human (or even the average musician) is able to detect. A really good ear for pitch might be able to start discerning a difference at about 4 cents but not I think in an instrument as full of non-harmonic series type harmonics as a tubular bell. I personally would try getting a really accurate tuner that measures in cents and measure your lowest chime. Try grinding the most fractional amount of mass from the lower end and see what difference it makes to your measurement. It might do the trick. I don't really know for sure though, but its what I would do. As far as the cracks are concerned - I reckon that fixing the cracks would help the tone a great deal although the quality of the fix is going to be as good as the quality of the repair. Obviously the top edge is where a tubular bell is struck, so the repair has to be able to handle that. I would Check with the manufacturer (if you can) or get some boilermaker perhaps to check out the metal first though. Different tubular bells can have quite different metal compositions, and you will most likely find them impossible to weld. (then again you might get lucky!) You might need to get a high temp silver solder or some kind of brazing job done in which case a plumber might be your best bet.
My apologies that all this is pretty much opinion and conjecture and not really proven experience. If you can find someone with a great deal more knowledge than me, then my advice is to talk to them ;-) I would appreciate a quick email on the results of your efforts with this one if you find the time, as there are always others who could benefit. I would like to put some more info on the website on this subject, as it comes up a few times.
Thank you so much for your reply. Those links you reference are very good for wind chimes, and I will hang on to them for that purpose, but not much help for orchestra chimes.
I have found a link that talks about the stoppers, and a wealth of other good info regarding Deagan chimes. I haven't digested the whole article yet, but apparently, the stoppers were used to tune the enclosed air column to match the frequency of the tube itself. The resonating air column would reinforce the resonance of the tube, producing a louder tone with more sustain, and less of the higher partials. If that's the case, that gives me a better idea of what I'm shooting for.
He is actually talking about something called "shaker chimes", or "organ chimes", which I gather are handheld and used in a similar fashion to the bells used for "change ringing". However, they are stopped at both ends, and the article does talk about the purpose of the stopper. Still not quite the same as the orchestra chimes I've got, but similar. I will try to email this guy to see if he has any other info or links as well. Unfortunately, the Deagan company has been out of business for a long time, 30 years at least, I believe. Their old rosewood marimbas are still collector's items though.
I made a typo in my original email to you. The chimes are tuned to A=435, and I need to raise them to A=440. That's actually about 20 cents. I agree that 5 or 7 cents is right on the edge of what most people can detect, but 20 cents is enough to be dissonant with the other organ stops. I do have an accurate strobe tuner, and a good quartz tuner as well, accurate to +/- 1 cent. They're accurate enough that I can measure the pitch change in a marimba bar by warming it slightly just by holding it in my hands for five minutes.
You raise some interesting questions about trying to weld the tubes, and I'm going to have to look into that. I can see that someone has tried to repair some of the cracks previously, using solder or silver solder, which is also cracked now. I hope these can be salvaged. The ones that still sound good have a marvellous tone.
One other thing I'll bounce off you - the chimes have a very small hole (about 1/16 inch in diameter) in the side of the tube, near the upper stopper. Any idea what that's for?
I believe the lower stoppers are just held in by paint, but also look to be a very tight fit to begin with, probably inserted by hydraulic press. Probably too tight, or the tubes wouldn't have cracked there. I may have to destroy the stopper to get it out, but making a new one out of aluminium or even wood, and then using epoxy to hold it in place, I believe would be sufficient.
I definitely will keep you posted as the project progresses, and please let me know if any other thoughts occur to you as well.
Thank you Marty for the links and info. That's very interesting about tuning the air column - I didn't know that. Ah yes - Deagan, sorry - of course they are no longer around, but you may (or may not) have some luck with Musser - many of the designs of earlier instruments were extremely similar if not identical. I did assume that you had made that typo - so that's ok, I knew what you meant - My mistake with the 5 cents sorry - of course you're right - at the end of a long day, my brain went straight from hz to cents without conversion - what a ditz!
I'm not sure if I know what you mean with the little hole toward the top.... - this may seem like a stupid question (sorry if it is) but its not the hole used for the suspension wire to hang the tubes is it?
I know what you mean about the 5 Hz vs 5 cents thing, as I did it myself, and I really should know better.
As for the "small hole", I'm thinking it's an "air relief" hole, like you'll find on the side of a drum - prevents trapped air from compressing and damping vibration. On the chimes, the mounting hole is about 1/4" dia. and runs completely from one side to the other so that a cord can be passed through to suspend the chime. The small hole is only about 1/16" dia. and just goes through one side wall of the tube into the inner air column - doesn't extend through the opposite side wall. But I'm really still guessing on its function.
I've learned that the chimes are actually brass, which surprised me. I thought they were a steel alloy at first.
I haven't heard anything from Musser, but Carl Dodrill (Pipe Organ Foundation) has been getting input from the "Pipe Organ Mailing List", some of which seem to be right on. There are a few people who have done exactly what we're looking into, so we'll be relying heavily on their input. I'll forward you a couple of the ones that I think are on target, as I think you'll find them interesting.
Basically, what needs to be done is 1) remove some of the chrome near the crack, 2) stop drill the end of the crack to relieve stress and keep it from travelling farther, 3) braze the crack (Tig? Mig? way beyond my knowledge!) 4) grind down the braze area, smooth it out, 5) rechrome the chime (don't know if you can chrome just the brazed area, or if the whole thing has to be redone) 6) retune the chime. Also, during brazing, the lower stopper has to be removed so that it doesn't get brazed in place. Still needs to be moved during retuning.
As you can see, it's an involved process. Right now, I'm just wondering if it's within the means of the Pipe Organ Foundation to do this, as they are a non-profit organization. Most of the work is done by volunteers, like me, but the welding and chroming need to be done by professionals, and I'm sure that's not going to be cheap.
Thanks again for your reply and your interest. I'll be sending you a few other articles here shortly.
Dear Marty.. Thanks for taking the time to get back to me with your findings.
I didn't realize the little hole was just in one side, but I think your guess is probably a good one. Seems a bit strange to need a separate air relief though if there is already separate holes for the wires. Perhaps it is strategically placed to help create an antinode in the air vibration inside the tube. Organ people would know more about the acoustics of these things than me, but given that its not just closed or open at the ends who knows what sort of modes they were aiming for inside the tube.
Sounds like the repair plan is about on track with what I would have thought - shame about the likely expense as you say. Electroplating is likely not too bad given that you have a whole set to do, - but then on the other hand...... You have a whole set to do. Mmmm... A whole lot of effort - one sometimes wonders if its worth it ;-) Perhaps you can find some kindly & well disposed retired boilermaker with a home setup just looking for something to donate his time to!
-----Original Message----- From: Pipe Organs and Related Topics To: Robert J. Rusczyk Sent: Tuesday, November 11, 2003 5:05 PM To: PIPORG-L@listserv.albany.edu Subject: Cracked Chime TubesHas anyone on the list repaired brass chime tubes that have cracks in them, typically an inch or two long and at one end or the other of the chime tube? I have some Deagan Class A chimes from about 1915 or so which were on an Aeolian organ, and several have these cracks. There are no pieces of the chime missing, just the cracks. The chimes are otherwise of excellent quality. How are these chimes best repaired? Thank you, in advance, for any help that can be offered.
-----Original Message----- From: Robert J. Rusczyk Sent: Tuesday, November 11, 2003 10:09 PM To: 'Carl Dodrill' Subject: RE: Cracked Chime Tubes Importance: HighCarl,
Contact Dennis Unks at OSI. Dennis (OSI) bought Deagan and Mayland several years ago and are fully prepared to repair and/or replace any portion of these product lines. Let Dennis know I pointed you to him and I am sure you will receive "special attention".....
-----Original Message----- From: firman1 Sent: Wednesday, November 12, 2003 12:05 PM To: 'Carl Dodrill' Pipe Organ List Subject: Re: Cracked Chime TubesHi,
I have the same problem with my two sets of Maas chimes. I tried closing the cracks with clamps and soldering, but that did not last long. Recently, I visited a collector of steam whistles. He repairs cracks with some form of welding using brass (or bronze). The repairs are barely noticeable. I believe it is called TIG welding. I will try to find out from him.
Date: Wed, 12 Nov 2003 07:04:07 -0800 From: Keith Bigger To: 'Carl Dodrill' Pipe Organ List Subject: Re: Cracked Chime TubesPractically all the tubes in our Deagan Class A 20 note chime set have cracked over the years. The temperature in the church tower where the Echo Division and Chimes are housed has been known to reach 100 Deg. F on some hot summer days. These hollow tubes have a plug force fitted into the bottom and the uneven expansion causes them to split. I found someone in Staten Island, NY who does bronze welding. He first stripped all the nickel plating off, before the welding. When he was done, you couldn't see the weld, and the chimes play as good as new. I don't know if he applied pressure to close the crack first before he welded, but if you want to call him, I will give you his number if you reply to me privately. I then rubbed on several cotes of a high quality, thinned out dipping lacquer to prevent tarnishing. If the chimes are on display, you would have to have them re plated. My guy doesn't do that.
-----Original Message----- From: David Holmes Sent: Sunday, 11 February 2007 8:25 AM To: firstname.lastname@example.org Subject: chime repairHello Jim,
Just ran into your letters with Marty on chime repair in '03.
I did a set of Musser high school chimes about 5 years ago.
No bottom stoppers. Top stops were vertically serrated and driven into the tubes hard. 11 tubes were cracked, too much pressure. Stops were driven out and turned down slightly with a file on a lath. Cracks were filleted slightly and the tube clamped tightly to close the crack. Fluxed and silver soldered with the standard readily available silver solder. 50- 50, I believe. Metal and solder heated and run well into and around the joint. Air cooled, then ground and filed inside and out and polished. No replating. Top stoppers driven back in and new support wires made exactly the same way as the originals. They all worked perfectly except one which was dead. Tone was there but no resonant volume. On one the stopper was turned down a tad too much and had a buzz. that whole cap was soldered on and it stopped the buzz. Musser's cost at the time was, if I remember correctly, $ 175.-per tube so the effort was well worth it.
PS.....If you know any one that has odd chimes tubes, I'd like to get a few. Have tried regular steel pipe also and they aren't too bad a sound, if you have a forklift to move them around.
MAKE AND TUNE YOUR OWN WINDCHIMES!
answers by Jim MCCarthy - 16/11/2003
For more help on instrument building you can email Jim.