Tubing Materials

 

 

From:  suppanz
Subject:  Re: Suspension holes of tubes

Most people seem to like to suspend them at 22.4% of the length. This is a point called a node and it does not move when the tube is vibrating in the "fundamental mode". If you have some tubes (or solid bars), try holding one between your thumb and forefinger at different points while striking. (Strike at the midpoint of the tube, preferable with a wood mallet.) If you hold it at just the right spot (22.4%), it will sustain a fairly long time. However, if you hold it at some
random place, your fingers will damp the vibrations out almost immediately.

Hanging with a string is a lot less restrictive than holding with your fingers, so the effect of moving the suspension point around is subtle. Even though it seems like a bad design, I've seen chimes suspended near the end and they still sound reasonably okay.

What about modes other than the "fundamental mode" you ask? Chimes actually vibrate in many modes simultaneously. Each mode contributes to the sound, and together all the modes give the chime its "chimey" sound. The fundamental mode has two nodes, each 22.4% from either end.
The second mode has 3 nodes - including one in the middle.

The second mode generates a higher tone than the fundamental (an overtone). In fact, you can hear the second mode by holding a tube in the center with your fingers and striking the tube near the end.

So, where you suspend and strike the tube is going to affect the amount of various overtones you hear and change the sound of your chimes. I've even seen chimes with a rubber band placed at some point to alter the sound. If you experiment around, you may find ways to stand out from everyone. Brad

 

 

From:  suppanz
Subject:  Re: Tubing Wall thickness

I believe that with a thin wall (say less than 0.035" for a 1" dia.), you get other modes of vibration coming into play (besides bending), which can affect the sound. However, as long as the walls are of very even thickness it's not very noticeable. But, with uneven wall thickness, you get beat frequencies because the tube can vibrate at slightly different frequencies depending on which direction it bends.
Also a problem with welded tube. However, with thick walls, the unevenness problem is less critical. If you want to use thin walls, try to get "drawn" tubing because the tolerances are very tight. Brad

 

From:  cllsj
Subject:  Re: Tubes...

> aircraftspruce.com

I priced 2" OD with a .065 thick wall 6061-T6 at onlinemetals.com and aircraftspruce.com. For a 6 foot length Aircraftspruce was a few dollars cheaper. Aircraft spruce will not provide shipping charges online. Three tubes to build my Dm chimes cost $15 to ground ship from onlinemetals.com. Aircraft spruce had a few more alloys to pick from. Online metals had more sizes to pick from. Aircraft spruce indicated you could only buy 6 or 12-foot lengths. Online metals will custom cut (for a fee of course) and will sell from 1 foot to eight feet. Chuck

 

From:  "Jack Maegli" <jackmaegli@jvlnet.com>

Music is an interpretation and no one should tell you what you think copper sounds like. You may want to play with Horne's Spectrogram for a while to see what frequency patterns appeal to you. I personally like octave harmonics (characteristic of string instruments) or single frequency response from tubes. The non octave overtones produced by "non ideal" metal tubes does not appeal to me personally, which is why I am a copper type K or L guy as opposed to the hardware store M stuff.

 

From:  randal frost <rkfrost@humboldt1.com>
Subject:  Re: Chime materials

Yep. It's the money. Last time I looked, brass tubing, 2" diameter is about $12.00 a foot! As for the finish, trumpet players often remove the factory lacquer to get a brighter tone. I don't know that it makes that much difference. The finish on my horn wore off years ago, and I can't tell much. As for flutes, the inner barrel is much more touchy,
as one must be able to modulate the airflow.
We get into this trap often, but a chime depends on vibration, where an organ pipe or other wind instrument is more dependent on airflow.
Consider that a wooden flute, while more mellow, still has the same basic sound as a silver flute, while wooden wind chimes are nothing like their metal cousins. RJF

 

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Long-Tube Experiments With Steel, Aluminum, And Copper

If it weren't for the fantastic, informative, and well-documented advice I've found in this site from the real experts, I'd still be beating on a bucket with a stick! So, even though I've only used the "Fred Flintstone" method for testing and the "tinker's" method of experimenting, the end result has (perhaps accidentally) proven to work very well with long-tube windchimes. I boast of nothing more than being a tinker, a musician, and an electronics engineer (in that order) - but not a windchime expert in any definition of the words.
Before I start, I've been given some extremely enlightening information from a close friend who's a metallurgical engineer for a company that contracts the supply and fabrication of many metal components for Boeing aircraft. Of course, we engineers tend to dive so deeply into theory and mathematics, that most people get totally bewildered before finishing the first sentence of some written thought. So, as a result of information he's passed on to me, I'm sharing some of the concepts he's presented - but in more "layman's terms" that I can understand a little better (haha).

NOTES ABOUT RESONANT LENGTHS AND WAVELENGTHS:
"Frequency" is a numerical count of how many sinusoidal, full-cycle energy or vibration waves pass a reference point in one second of time; that number is either stated in "cycles per second" or "Hertz".

"Time Base" of any frequency is the time (in the decimal amount of one second) it takes to complete one, sinusoidal, full-wave cycle.

The "wavelength" of any frequency is simply the linear-measured distance (along an ambient norm or "zero reference point") that it takes to complete one, full-wave, sinusoidal cycle of the energy or vibration wave (starting at the beginning of the "positive" pulse and ending at the end of the following "negative" pulse).

"Resonant Length" is simply when some conducting medium is cut to a length that's equal to one wavelength of a particular frequency (through that particular medium). Under this condition, a state of "resonance" exists where there is minimum impedance, highest "Q", and maximum wave propagation conditions offered for that particular frequency.

Calculating the wavelength of any low-frequency vibration, sound wave, energy-transfer pulse (or whatever one wishes to call such) is a spin-off of the old (distance = rate X time) formula. "Distance" would be the wavelength in whatever unit of measure one chooses to use (inches or cm). "Time" would be the decimal amount of one second it takes to complete one, full-wave, sinusoidal cycle. "Rate" is a major can of worms because it's the particular "speed of sound" (inches or cm per second) that wave propagation moves through any particular conducting medium. During the single-cycle "time base" of
some particular frequency, the faster that sound can travel through a conducting medium will result in the waveform covering more linear distance (along the medium) during that cycle's time base. Back to layman's terms: the faster sound can travel through a particular tube, the longer that tube will be (for a particular tuned frequency) in comparison to a tube where sound isn't traveling as fast.

STEEL, ALUMINUM, OR COPPER?
Even though I was using equal lengths of 1" OD tubing, it was a tough shot to get a perfectly true comparison because the steel conduit was galvanized and had a wall thickness of about .065", both the standard and anodized aluminum tubing had a wall thickness of .060", and the type-L hard copper was closer to .050" in wall thickness. I've learned from my friend's information that the "speed of sound" through any metal tube varies greatly due to inherent properties of material used, wall thickness, alloy composition, atomic density (up to a point), and the metal's temper (type, degree, and direction) if
any exists. Additionally, in tubing of the same exact metallurgical composition and properties, "sound" (pulsating energy-transfer waves) will travel down a thinner wall faster than a thicker wall. Therefore, when "tuned" to some fundamental frequency, the thicker wall tube will be shorter than the thinner wall tube of the same metallic composition and properties.

The particular sound, tone, perception, and timbre that one finds most pleasant or is trying to achieve will probably be the determining factor of whether to play with steel, aluminum, or hard copper tubing. Obviously, my experiments with equal lengths of all three types of tubing not only gave considerable differences in all of the above, but also generated a totally different "fundamental frequency" due to the different speeds of sound and different wall thickness. Another major difference occurred when each tube was either struck in the middle or struck near the end. As far as particular or
desirable tonal qualities (or lack thereof) are concerned, my educated friend tells me (which I sadly verified later) that even tubing of the same exact type from the same manufacturer (but from different manufactured lots) will produce amazingly different results; this even happens with extremely expensive aircraft-grade metals (but to a much lesser degree). So, get ready to beat your head against the wall if you try making a tuned set of chimes (from different stock) with all the mathematical formulas - cause it ain't gonna happen!!

Just so I don't confuse anyone any further, let me take a second to define MY particular concept of the difference between a "bell-like" sound and a "chime" sound. While both produce a long sustained "ringing" perceived sound, I refer to a "bell-like" sound as one where a single fundamental or overtone frequency is predominant to the ear, while everything else either decays very rapidly or is at such a low level to be non-perceived; a "bell-like" sound is easily tuned to some particular musical note because there's little or no interference from everything else. Conversely, I refer to a "chime" sound as being extremely difficult to tune to some perceived musical note because it presents (and sustains) rich and equal levels of fundamental frequency and many overtones; the cumulative "perceived" tone is sorta-kinda some particular musical
note, you can hum along with it, it "blends" with some actual musical note from an instrument, but then - well, it still isn't that exact note. I suppose a bell-like sound is a pretty good musical note, but a chime sound seems to only harmonize with a particular musical note without actually being a definitive note in itself (if that makes even the slightest bit of sense).

Striking any of the three tubes in the middle gave a more "bell-like" sound and perceived musical note. I'm sure this is a result of the strike occurring at the second harmonic wavelength point and initiating the vibration pattern outward toward both ends of the tube. The resulting standing wave process of resonance would cause less initial excitation of the fundamental frequency (and perhaps even the 1st overtone). Striking any of the three long tubes at the end produced a definite, very rich "chime" sound because this is the major excitation point for the fundamental frequency (and harmonic frequencies) to produce many overtones. My metal guru explained that when any piece of metal is struck, it produces the
entire spectrum of audible frequencies for a split-second (that's the "clank" you hear for a micro-second during the strike); but only the fundamental frequency (and it's harmonics) which see a state of resonance will survive long enough to be actually heard and perceived because every other frequency rapidly decays in a non-resonant environment. He sorta blew my brains with the "excitation coefficient of atomic collision" concept; but, basically I gathered that striking the tube anywhere with a hard object or knife-edge object will excite the higher frequencies considerably more than the lower ones; while striking the tube with a softer or wider surfaced object will excite the lower frequencies more than the higher ones. So, you'll find that any tube of any material will respond differently by both the point where it is struck, and what it is struck with.

PS - while running off about cleaning and polishing aluminum, I failed to echo the comment from "bs" about using tubing from old folding chairs. I've also noted that many of them are made of very soft (almost pure) aluminum that's very soft, bends very easy, and doesn't have much wall thickness. Before selecting something to use for windchimes, try to find an open end of the tubing and make sure it's not extremely thin-walled (the thicker the better). Next, use Fred Flintstone's "tink test" by tapping on the tube with a piece of hard steel (back of a pocket knife blade, dad's .45 automatic, etc.)
and listen for a very bright, very pronounced "tink" sound to see if it's a hard enough alloy to work well. If you practice "tinking" on different types of metal (hard and soft) beforehand, you'll see what I mean.

What sounds good to you and/or what you prefer to look at (as far as aesthetics go) will guide your choice of tubing to use. Once again, the metal expert advised that the temper (if any), direction/vector of temper (if any), the hardness factor, modulus of elasticity, coefficient of rigidity, atomic composition, wall thickness, and diameter of any metal tube will all enter into what particular "sound" is produced, and how long certain frequencies and/or bands of frequencies will sustain oscillation for the longest period of time. So, here's what I seemed to note:

STEEL: High speed of sound and took a longer length to produce a given frequency. It had a "brighter" more "metallic" sound than the others. My guru says this is because steel has a much higher co-efficient of rigidity which (due to it's lesser ability to flex) quickly dampens lower frequencies and allows the higher frequencies (more in the peak human hearing curve) to sustain oscillation for the longest period of time. If you're looking for a higher "bell-like" sound, then steel is the best choice. The down side of steel (even if plated or galvanized) is that it eventually begins to rust and/or pit- especially at the mounting holes.

ANODIZED ALUMINUM: Must have a speed of sound near that of steel because length and tonal qualities were very similar. The guru says the aluminum alloy that best accepts the anodizing process is a much harder and denser alloy than the usual garden variety of plain aluminum tubing. Having a less coefficient of rigidity, the anodized aluminum wasn't quite as "bright" in overall sustained sound because it's a bit more flexible and causes the very high frequencies to decay faster; but it was a bit longer responding to the mid-range frequencies than the steel. Still a great choice for anyone
looking for a tuned "bell-like" sound. Even better, the anodized finish looks better than any of the others and lasts indefinitely, it won't tarnish or rust, is much lighter, and can be suspended by smaller diameter line. The down side - it's expensive!!

PLAIN ALUMINUM: A little softer material with a bit slower speed of sound; so a tube of some tuned frequency would be a bit shorter than one of either steel or anodized aluminum. With a lower coefficient of rigidity, it produced a very good mid-range band of frequencies. Higher frequencies didn't sustain as long as the steel or anodized aluminum. If struck in the middle, it gave a pretty good "bell-like" tone, and a strike at the end produced an acceptable "chime" tone as well. It
too, is light and doesn�t tarnish too badly with age; but it is also pretty pricey as well.

HARD COPPER: More "mellow" and less "brighter" sounding than the others. The type-L hard copper must have been very similar in the speed of sound properties because it's length vs. produced frequency was very close to that of the standard aluminum tubing I had. Striking it in the middle produced an acceptable (but very mellow) "bell-like" tone, but striking it at the end gave a beautiful, deep "chime" sound better than any of the others. Having the lowest coefficient of rigidity (compared to the other tubes), the higher and upper mid-range frequencies (above about 1,500Hz) decayed pretty rapidly; but the fundamental, first, third, and fifth overtones (all below 1,500Hz) sustained for a much longer time than the other tubes. This long-lasting, deep resonating "chime" sound is obviously the reason that long, large orchestra chimes are made of
hardened brass instead of aluminum or steel. Good points are that it's readily available and moderately priced. Down side is that it quickly tarnishes to a dull, blue-green color (but my wife loves it-so, I'm safe there). I suppose one could go out every few days and polish their chimes, just hope the neighbors aren't watching. NOTE: Here's where I got my lesson in tubing. Didn't have enough of my original tubing purchase left to make my shortest (C3) tube in the 8-tube set. Same store, same tubing, same type, same manufacturer, but a different lot. Cutting the tube using the same criteria as the others produced the same exact note as one of my other tubes (which happened to be a full 2" longer) - grrrrrrr.

The bottom line with what I've found is what I first said; choose the particular tubing that will produce the particular sound you're trying to achieve. My preference was simply a deep, long-lasting, mellow chime sound - that's part of why I went with the hard copper.

HOW CAN THE LAWS OF PHYSICS FURTHER FLUSTER A CHIME-BUILDER? With respect to a solid chime rod/bar and a hollow chime tube, the difference between the properties of the two is a complete night/day concept. Vibrations running across, along, and through a solid piece of metal have totally different wave-propagation patterns than those in a hollow tube. The solid rod or bar creates a waveform propagation that is influenced and shaped by a constant, three-dimensional uniformity of both matter and density of the medium; but a more complex, spiraling "skin effect" set of waveforms are created by a hollow tube where there is no cross-sectional uniformity in mass or density.

However, none of the above differences can hold a candle to the MAJOR difference between a solid rod and a hollow tube - THE AIR INSIDE THE TUBE!! Many have either disregarded, lightly touched upon, or mistakenly theorized about what's going on with the air inside a hollow vibrating tube; to think this factor has little or no effect is not only a major mistake, but also is probably a significant reason why the "math" seems to have many questionable and unexplained variations in accuracy. Even though the surface vibrations of a solid rod and hollow tube have very different waveform properties, both
produce an excitation of the surrounding air molecules that produce "sound" waves we can hear; and, in a similar manner, both are simply exciting the surrounding "free air" that has no restriction of movement in any direction. Yet, there is a much greater degree of air excitation happening inside a hollow tube because the air is not only being rapidly compressed and decompressed by the tube's oscillating walls, but the excited air has only two directions in which to vent those fluctuating pressure changes to the outside world (out each end of the tube). Because air movement inside the tube is being severely restricted by the tube's walls, those pulsating pressure changes within the tube are considerably more radical than those happening to the "free air" along the outer walls of the tube (where air movement is not restricted).

Anyone who feels there is no air pressure difference at each end of a long, open tube needs only to place their eye, upper lip, finger tip (or any other sensitive part of their body) very near (and in line with) one of the tube's open ends. Now strike the tube, and "feel" the major pressure pulsations coming out its end. I challenge anyone who argues with the degree of this "internal air column" concept to try a simple experiment that will quickly prove my point. Find yourself a nice, steel, 50-gallon oil drum and remove both ends to form a large hollow tube. Lay the drum on its side, stand with your
ear about one foot from the outer surface, have someone give the drum a few whacks with a rock, and observe the "loudness level" of what you hear. Now, get on your hands and knees, stick your head inside the drum, have your assistant whack it again with the rock, and - WOW! - you will note the difference with no problem at all!! If you still have any hearing left, put a lid on one end of the drum (to block off one "air escape route"), stick your head back into the open end, and have your assistant whack it with the rock one more time. After noting the result, you will probably back out of the drum,
retrieve the rock from your assistant, and whack him a couple of times with it.

Please be warned that my experiments have been confined to relatively long tubes in the F1 to C3 range; so, I cannot guarantee the same results with much shorter tubes because I haven't tried it yet. I'm not really interested in "bell-like" tone because I simply prefer the rich, mellow, deep "chime" sound much better; so, I don't know if capping or top/center suspension of a tube will work as well for anyone using a center-strike to produce "bell-like" sounds from steel
or aluminum tubing (that's more efficient in at such). Since there are no readily available, thin, preformed caps for steel or aluminum tubing, I'd think one would have to weld an internal disk into the end of those tubes (and I can't say if the extreme heat of doing so would degrade the tube's properties or performance). I don't claim authorship or invention to what I've given here; just (perhaps) a "discovery" of why orchestra chime makers do what they do after evolving the "chime sound" (along with capping and mounting techniques) over the past 500 years or so. Brent

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  More Tube Stuff

Wow! Whether anything I've posted has any particular merit, substantiated truth, or practical value, it's good to see so many folks here taking an interest (either positive or negative in nature) because it seems to have sparked the enjoyment that everyone attains from simply getting off their butts, going back to the shop, and playing with new ideas or concepts. It matters not if one's objective is to see if something works, expand and innovate something to the next higher plane, or to simply prove someone (or some concept) wrong; the only goal I seek is to help perpetuate enthusiasm and experimentation in a hobby we all seem to enjoy.

Chuck raised in interesting question about how the hard copper and aluminum tubes of the same length could possibly manage to give very close to the same resonant fundamental frequency when the aluminum and hard copper have such different densities, and other qualities. Granted, wave propagation speed through copper is a bit slower than through aluminum; but as I said as a "disclaimer" the copper tube had a .050" wall thickness and the aluminum had a .060" wall. In tubing of the same composition, the speed of wave propagation is faster along a thin wall than a thicker wall. My metal guru says that
very hard copper is an alloy of lighter stronger properties and is far from being pure copper - thus getting a little closer to many common aluminum alloys in wave propagation speed. But, since the hard copper tubing was about 20% thinner than the aluminum tubing, the increased wave propagation speed through the thinner, less efficient copper probably was offset by the "slowing" of same by the thicker walls of the aluminum - thus being close in fundamental tone at equal
lengths. If the aluminum had been of a .050" wall thickness (like the copper), it would have produced a higher fundamental resonant frequency than an equal length of copper - and, as expected, would require a longer aluminum tube to get the same fundamental as the hard copper.

Denyse is my kinda folks - because no real tinker can function without duct tape, bailing wire, super-glue, and J.B. Weld!! If you're using copper tubing of 1" OD or less, you won't need to flare the top of the tube because any plumbing supply carries pre-formed copper caps which are made to snugly fit over the end of a tube (extending down about 1/2 to 3/4 inch over the outside of the tube) to be soldered in place with nothing more than a little propane torch (that's what I used. I know you can get caps for up to 2" tubing (maybe larger) but, unless you found a true plumbing supply store, they would probably have to be ordered. NOTE: If soldering copper, I'd recommend the newer rosin-core, non-lead plumbing solder (even
Home Depot has it). It's about 95% tin, 5%Antimony, and much harder than the old 50-50 lead/tin solder. I recommend rosin-core because the acid flux will do nasty things to the copper under the cap in places where the solder doesn't completely flow; you simply need to make sure to clean the inside of the cap and area around the top of the tube with steel wool so the solder will flow better and more evenly. If you want to use JB Weld, I can't see much harm in that either because it has a pretty hard consistency after it sets up, should hold the tube OK if you hang it from the cap, and would block
the air at one end of the tube as well as solder.

I'd like to hear what kind of results anyone gets from capping steel or aluminum tubing (like Chuck as mentioned) to see if it either provides any tonal sustaining increase at all, or gives an easier way of mounting long steel and aluminum tubes with the same unnoticed change in dampening (from traditional node mounting) as I've noted with long copper tubes. It would also be interesting to hear if this does anything at all for shorter tubes (less than 3 feet in length).

Another interesting concept my metal guru suggested I pass along to anyone interested (which, in his aircraft construction, is totally adverse to his professional goal of total non-resonance of any tube). To get the most "sound" out of any tube, go with the thinnest wall you can find that is practical to work with and sturdy enough that it won't get dented by your striker. I once read an interesting article where the author mentioned what an absolutely beautiful ringing sound he got from an old vacuum cleaner's extension tube that was very hard, very thin walled, chrome plated steel; but finding and buying anything like that (in enough length to make long chimes) would cost a fortune. But, since the thinner wall tubing will be longer for any fundamental frequency than a thicker walled tube, you'll not only have more surface area to excite the surrounding air (louder sound), but the thinner wall will also oscillate to a greater surface and cross-sectional degree of movement - thus offering more air excitation than a thicker wall with less surface movement. It's the same comparison as a small speaker and a large speaker being fed the same audio tone input; the larger speaker simply moves more air and sounds louder. So, the optimum in loudness would come from a very long, very thin-walled steel tube because the steel would be longer than other tubes to produce the same fundamental. More tube, more vibration, more loud - cool!! Brent

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Aluminum Alloy Tubing and Pricing

While I was researching places to buy aluminum tubing for a little project a couple of months ago, I ran into some good information that may help prevent major frustration in tuning an aluminum tube while explaining the diverse degrees of sound qualities that may also be encountered. Most all of the frequency/length/OD calculators, charts, and spreadsheets are pretty good at providing reasonably close lengths from which one can begin to tune a copper or steel (EMT) tube; however, when it comes to aluminum tubing, you can expect a considerably higher degree of error which (in some cases) may require
using some form of "correction factor" for the particular tubing you may have.

The reason for this anomaly is not from any mathematical errors; instead, it is due to the tremendous inconsistency of what is referred to as "aluminum tubing". A primary variable factor in Euler formulas is the exact rate of kinetic energy transfer "speed of sound" through the particular metal being used. Since all copper plumbing tube is 99.9% pure copper and most steel (EMT) tubing is well over 90% iron, there is little problem with figuring the exact speed of sound through those primary elements. However, aluminum is an entirely different animal because one will almost never find aluminum tubing that is anywhere close to being pure aluminum.

Pure aluminum is extremely soft and almost as malleable as pure lead; as a result, a pure aluminum tube could be easily chewed in two, easily bent or dented, and would produce a dead-sounding "windthud" that would probably be worse than that produced by flexible, annealed (soft) copper tubing. Therefore, to make aluminum practical to use as a structural material, it must be highly alloyed with other metals to give it strength; yet, unlike "steel" where the iron content is always the overwhelming major composition percentage, many aluminum alloys actually contain a higher total percentage of other elemental metals than it's percentage of aluminum content. During my online research, I was surprised to find that there are over twice as many registered industrial aluminum alloy numbers as there are for steel.

I found scores of structural aluminum tubing alloys that had as much as 30% iron content, as little as 30% aluminum content, with the rest made up of copper, zinc, nickel, titanium, magnesium, manganese, and chromium - yet it was still listed as "aluminum tubing"??

The bottom line here is that, unless you have the fat book of industrial alloy numbers vs. alloy content, you really have no idea of what you're getting when you buy "aluminum tubing". Since there is usually a major content of other metals present in an aluminum alloy tube, the calculated "speed of sound" through pure aluminum may very well be considerably faster or slower as the alloy content's component elements and relative component percentages change; thus, there can easily be more degree of error when figuring length measurements for some desired tone frequency.

Howard was correct in his assumption that, in most common aluminum tubing (in common diameters), you are buying it by the pound more than anything else. Aluminum is almost as pricey as copper, and steel prices are about to pass them both up. So, many times the price difference you see between different manufacturers for the "same" 1"OD aluminum tubing is NOT necessarily a matter of simple price competition, but is more likely being determined by the actual amount of pure aluminum that is present in the particular alloy they sell. Translation: a 1"OD/.058"wall aluminum alloy tube that contained 70%
pure aluminum would probably be more expensive than an equal sized tube that was only 50% pure aluminum. Keeping that thought in mind, the concept of "the more expensive, the better in quality" does not always apply to aluminum alloy tubing that's best for making windchimes. Very expensive tubing with an extremely high aluminum content is going to be relatively soft and would probably not produce a tone quality as good as hard copper; yet a less expensive aluminum alloy with a higher content of harder metals would closely approach the sound of steel EMT.

The reason I earlier plugged Texas Towers as a good source for .058" wall, drawn aluminum tubing (up to 2-1/8"OD) is because the particular aluminum alloy they stock probably has a very high content of iron and zinc; thus making it much harder, cheaper, and better sounding with respect to making windchimes. TT's primary business is building huge radio towers and supplying high-grade structural aluminum tubing to makers of expensive radio antennas which must be able to withstand up to 120MPH winds without bending or breaking. After building a set of 2"OD chimes from their aluminum tubing, I will quite frankly never use steel EMT again. The stock I got from them was very hard, very resilient, sustained higher frequencies almost as good as EMT while doing a better job of sustaining lower frequencies a bit longer. When combined with the lighter weight, no problems with rust, and being very close in price per foot, why bother with EMT? Brent

 

 

From:  "Mark Harris" <marksjob@cox.net>
Subject:  Re: Mark Harris -- steel tubes

Denyce,

Don't be afraid of stainless. It cuts very nicely unless it is a particularly hard variety. 304 to 316 cuts like mild steel. But and a big but is. If you get it hot, it becomes hard and brittle. It will break a drill bit pronto if you don't keep it cool with lubricant. A hacksaw should be no problem. However, a lathe with a cut off tool would give you a
beautiful cut. See if you can get a 316 stainless washer at the hardware or marine store. I would suggest you silver solder it. Stainless silver solders very well, but you will have to get it quite hot. This means you will have some finishing work to clean and polish it. Practice on a small piece before you go to your tube. Mark

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: Steel - Copper Tube

I love this place because, whether an idea turns out to be good, bad, successful, or unsuccessful, it's still an idea that many times needs further exploration - especially to us tinkers.

Denyce's thought of joining two different tubes of dissimilar metal has piqued my interest enough to figure a way to do it, and also has challenged Chuck's interest to generate a "virtual" computer model to incorporate the actual math and physics which would hypothetically exist in such a marriage of metals and the "shift" in their individual properties that would result as a product of the whole.

Pulling from my "tinker" experience and Fred Flintstone knowledge, I'm unaware of any existing method to physically join steel, copper, and/or aluminum with any degree of seamless continuity for an experiment. If such true bonding were possible, I'd think the "joint" would immediately begin to deteriorate from the electrolysis produced between the two different metals in direct physical/atomic contact. As I pondered earlier, it seems that some sort of joining collar would be necessary to make a joint that had any strength at all.

If someone else doesn't get curious enough to try it, I may be forced to do a little experiment myself - just to put my mind at rest. I'll probably use the earlier thought of using a commonly available copper joining collar (which has a thin "girdle" around the middle to center both tubes; then, cut it down in length with a pair of tinner's snips to about 1/2" in length (allowing a bit less than 1/4" of each tube to be inserted in the collar. I haven't tried the new lead-free (95% tin) rosin core plumbing solder yet on the galvanized (mostly zinc) electroplated steel conduit, but I know the acid core works great. The tin solder would flow between the collar and steel tube to create a "happy medium" that would cause little or no electrolysis in the joint. As Chuck pointed out, any predicted tone or fundamental frequency would be almost impossible to predict; and, as a result, any "node" mounting point would be equally difficult to determine in advance. So, I (or anyone else) might try the "capping" thing by soldering a cheap copper plumbing cap on the open end of the copper tube (guess it would work on the galvanized steel tube as well); then drill a hole in the center of the cap and use the single-line, end suspension that doesn't seem to affect a tube's overall performance and/or tonal qualities.

I know the short collar's presence and 1/2" length of doubling the ambient wall thickness will also toss another clod in the physics churn, but just doing it to see what happens has me almost interested enough to try it. I would think that one should use a longer tube with at least 2' of each type of tubing to get a little better hearing perception of what may or may not be produced when compared to a total equal length of all copper or all steel tubing. I'd also think that using larger diameter tubing (from 3/4" to 1") might also give a little more wiggle-room for comparison to other like-metal
tubes as well. Might be worth a try! Brent

 

From:  "Doug Wiseman" <dougwiseman@prodigy.net>
Subject:  Re: Steel - Copper Tube

I may be stating the obvious, but in the plumbing world galvanized pipe and copper don't mix. The standard solution (especially for water heater installation) is a dielectric union (I think I spelled that right). It uses ceramic or other nonconductive material to electrically separate the metals. It is threaded and comes commonly in 1/2" and 3/4". There are surely other sizes. I don't think its use would give the desired "marriage" of the two metals and would very likely create a break in the sound transference from one to the other. So, here is a suggestion of a possible connection that is not
a recommendation.

 

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: chromatic chimes

I've never tried building a full chromatic set of chimes for the simple reason that it would be a whopper with 13 tubes (if you started and ended the scale with the same musical note one octave apart). If you wanted to hang them in a row to play with a mallet (like orchestra chimes), I suppose one could have a ball in playing a tune. Of course, if you were simply using them to manually play a little tune, you may as well go for a two-octave set of 26 chimes hung in a row.

If you're really thinking about a full chromatic set of manually struck chimes (one or two full octaves), I'd stick to
the shorter tubes of less than 3 feet because it's easier to tune them for a better perceived musical note. Longer chimes have more overtones in the audible range; and since the overtones are NOT exact harmonics of the fundamental frequency (or each other), the more of them you add to the "ear mix" the more difficult it is to perceive a clean musical note from the jumble of different frequencies present.

Check out all the links here and first go through Chuck's informative web page to get a handle on tuning, mounting, and chime theory in general. Lee Hite's Excel worksheet is very good for getting in the "ballpark" for frequency vs. tube diameter and metallic composition. I've found that different metals and different diameters of tubing have inherent properties of being more favorable in sustaining some particular overtone steps than others; I've even noticed that capping the end of a tube and different suspension methods also affect the level and sustain degree of the different overtones as well. Usually, it's best to decide on some particular type, diameter, and wall thickness of the material you're going to
use, cut a piece to hang (in whatever manner you choose), then use some of the free "spectrum analyzer" software programs available here to get a handle on how your rig is going to perform (with respect to the particular overtone(s) most predominant to producing the perceived sound and musical note you hear) - then, build the rest of the set with that as a general guideline.

If your tube is short enough to have a fundamental frequency that's well within the peak human-ear response curve, you may perceive that frequency as predominant; but, if one (or more) of the produced overtones is more prevalent to your perception of some frequency or "musical note", you will be better off in cutting the other tubes with respect to achieving that particular overtone(s) rather than using the fundamental frequency as a base for length cutting. For example: your "test tube" seems to give you a well-perceived musical note from its 2nd overtone (and not the fundamental frequency).
Rather than cutting the rest of the tubes with the fundamental frequency being the determining length (with respect to the musical scale), look through the charts for the best musical step between 2^nd overtones produced - then cut the next tube to whatever fundamental frequency length is specified to produce that particular overtone(s).

Even though I'm a musician, I don't own a Korg tuner; but I've seen many different models that all work very well - especially the handheld, portable ones. Many here use the Korg very successfully for tuning anything - including chimes.

If you build a chromatic set of chimes, the first thing to remember is that the wind will play whatever "song" it chooses; so, random hits on a chromatic set won't always produce a harmonious or melodic sound. Many choose to build a particular chord or use the pentatonic scale to find something that cumulatively give a melodic sound that's pleasing to the ear during random strikes of each note. However, there is also a great following that find pleasurable, pure aesthetics in totally random "notes" from different chimes which have absolutely no musical relativity with each other whatsoever. I
suppose this is a strong case for "beauty lying in the ear of the beholder".

If you have a chromatic set that encompasses a full octave, your limits to playing any tune manually are unbounded because you have all the possible musical notes. Spanning more octaves gives a better effect because the upward or downward melodic progression of any song or melody can be carried on (in that particular pitch direction) without interrupting the flow by going higher or lower in a single octave to find the next note.

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: Drawn vs. Extruded vs.?

My metal guru agrees with Chuck's thoughts on drawn vs. extruded tubing of any kind. Both types of tubing are seamless and both come from continuous-feeding, circular molds (and in some cases, the same mold). If made from the same alloy, both types of tubing usually also have the same general temper and physical characteristics.

Extruded tubing is simply pushed out of the mold by the force of the molten metal that's being fed into the mold at very high pressure. As the tubing exits the mold and the finished product moves along down a long avenue of rollers, slight irregularities in its movement can cause very minor variations in wall thickness. These slight variations in wall thickness are so minor that they could seldom ever be seen and only measured with very delicate equipment. Normally, most applications can use extruded tubing with no problems at all; but in aircraft, aerospace, or precise manufacturing needs dictate tubing with the most consistent degree of wall thickness, drawn tubing is used.

Drawn tubing starts out by being extruded until the end of the finished product is attached to (or grasped by) something that will pull (or draw) it from the mold. Then, the pressure on the molten metal feeding the mold is dropped to just enough to feed the mold, and the tubing is continuously drawn from the mold by the pulling device that's running at a very precise speed. This keeps the tube moving from the mold at a very constant rate and ensures the best consistency of wall thickness that can be achieved without actually machining the inside and outside walls of the finished product.

In either case (as Chuck notes), there's no need to go to the much higher expense of using drawn tubing for making chimes because the difference in consistent wall thickness is so extremely minor that there would be no noticeable difference in the sound that would be produced when a length of either type of tubing was stuck. Brent

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  New Chime Tube Metal?

My imagination has been terribly piqued by a recent discovery made quite by accident yesterday. Like everyone else here (whether they admit it or not), I'm obsessed by giving a little jingle to any set of windchimes I see hanging in a store - just to grimace at the pathetic sound most of them produce. Some of the really expensive sets can come up to what I'd consider a "moderately acceptable" level; but most are the usual lackluster attempt to keep down production cost by focusing on aesthetics, pretty designs, and cheap materials at the sacrifice of sound quality.

That all came to a screeching halt when I was browsing through a little gift shop in the tiny, one-horse, rural Texas town that's about 4 miles from my country home. This was a cheap little $35 set of Chinese made chimes that consisted of a (poorly cast, pot metal) decorative suspension cap and very heavy sail, a crappy little wooden disk for a striker, and five little 1/2"OD chime tubes that ranged from about 18" to 10" in length. Giving it my usual little thump and walking on down the isle, I had to stop and turn back around because (even with my lackluster hearing) the damn things were still ringing
from just one tiny whack of the striker. Walking back about 25 feet to inspect them further, they were still ringing and ringing and ringing!!!

The 1/2"OD tubes were absolute junk in appearance. They had extremely thick walls (perhaps about .150" to .200" thickness), and appeared to be cast instead of cut pieces of tubing. They were node mounted with little plastic tubes as a cross-sectional abrasion shield for the very thin mounting line (that appeared to be black, braided nylon fishing line). The tubes were a dull aluminum or dingy galvanized steel color; but their weight was too heavy to be any aluminum alloy
I've ever seen and too light to be steel of any kind. I'm guessing it's some very heavy aluminum "pot metal" alloy (of some sort) that's been crudely cast in a mold.

I am not easily impressed (OK, except for the six-pack and the bug zapper); whatever kind of metal stuff these things are made from, it just won't stop ringing - WOW!! Got no help at all from the shop owner because they get them from some import distributor, and the little "brand name" tag is nothing more than a non-descriptive piece of eye-candy that's put there to give them a pretty marketing touch. I'm so impressed that I'll probably go back tomorrow and buy a set-just so I can give one of the tubes to my metal guru in hope's he can do a little backroom analysis of the alloy. Of course, that will not
do a lot of good when such is probably not available here (and the Chinese manufacturer may be untraceable), but I'm gonna give it a try anyway. I'll let you know if I find anything out at all because the tonal quality of this "junk" beats anything I've ever heard. Brent

From:  cllsj
Subject:  Re: New Chime Tube Metal?

"Pot Metals" tend to be zinc alloys. These are fairly easy to cast. They are nice and shiny. And would be fairly heavy. I've not checked but I suspect zinc has a low modulus and high density more like copper. With a 1/2 OD and the length you mention I would suspect they will ring at one of the higher modes. Chuck

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: New Chime Tube Metal?

You're absolutely right about them ringing at a higher mode (perhaps from the extremely thick walls), but I've never ran onto anything which sustained the ringing effect as long as these things did.
Considering the not-very-shiny, dull-silver color and their particular weight, I'd say the jury is still out on them being either a zinc alloy or very heavy aluminum alloy. As an engineer in the wireless communications industry, I've seen many types of fairly heavy (but much lighter than zinc, steel, or copper) RF helical resonators which were made of a cast aluminum alloy that must have contained considerable amounts of either copper or zinc because large copper coils and other thick component leads were mounted through holes in the casting and rosin-core soldered in place. These castings and other similar, tuned RF cavities were much too light to be a primarily copper or zinc alloy (which are both heavier than iron or
steel), yet they were noticeably heavier than similar cast aluminum cavities which were not designed for any solder-affixed component.
Most zinc alloys, as you noted, are fairly shiny silver in color, but these are more of a dull, weathered-aluminum color. Even though the cast RF cavities I mentioned wouldn't have made very good chimes (they looked like a thick egg carton with square chambers), the metal alloy gave a very sharp "tink" when tapped and was so hard and brittle it would quickly break instead of bending. I don't have a clue about where anyone would look to find any cast tubing made from such an alloy, but I'm certainly going to explore a little. As I said before, I've never heard any chime of any metal or alloy that sustained a very loud, high mode for such an unbelievable length of time. Brent

 

From:  cllsj
Subject:  Re: New Chime Tube Metal?

I searched Google Groups for pot metal to get some more information. I think the best definition was that pot metal is a metal with a low melting point. It can be thrown in the pot and melted easily. 800 F was the temperature I saw for the expected melting point. Different groups use the term for different metals. A post mention plumbers use the term for lead alloys. I also saw that "as cast" the finish was a dull gray and had to be polished if one wanted shiny.

I think aluminum and copper alloys would not be considered pot metals since their melting points are higher than 800 F.

The rec.metalworkers were doing their own casting. Maybe we could cast our own tubes. After a few burnt fingers, I think it would make cutting tubes to length seem trivial. Chuck

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: Sample Sounds

Here's a good set of questions for Chuck and Jack:

I took a peek at the website Damyon found, and was interested to see and hear the results. It was also interesting to see that all of the tubing they used (regardless of OD) had 1/4" thick walls. If they haven't "enhanced" their audio clips, the long-sustained sound must be due (at least, primarily) by the very thick tube walls. Perhaps this helps explain the very long-sustained tone I heard from a cheap little set of chimes (I described in a previous posting) made from cast aluminum alloy of some sort which had about 1/8" thick walls.

These expensive chimes have an even longer sustained tone and appear to be a very good grade of extruded aluminum tubing. Unless their photos have been altered to "hide" the suspension method, the tubes appear to be single-cord, center-suspended from a solid, internal "upper node" axle that's been aluminum-welded in place; and the tube's outer surface polished to hide the weld points (which would be fairly easy when using such thick walled tubing. I can understand their asking price because 1/4" wall aluminum tubing is terribly pricey (if one can find it); so, even with large quantity purchases, I'm sure they've got a lot tied up in material costs alone.

So, the questions for Chuck and Jack:

1. The extremely thick walls would seem to favor only the transversal mode and almost completely eliminate any noticeable sound production from the circular mode and cross-sectional/axial modes. Would using such thick wall tubing create a more "pure" sound as a result?

2. I know the internal air-column will still be influenced and excited by the thick-walled tube's transverse mode; but would the internal air-column have any noticeable effect (or even be considered) when using extremely thick-wall tubing from 1/8" to 1/4"?

3. Have either of you experimented with such very thick tubing to see if the extreme wall thickness sustains an audible tone considerably longer than the thinner wall stuff we've played with in the past?

4. The sound from these chimes sustains to unbelievable lengths; is this primarily due to their extremely thick 1/4" walls?

5. I also noticed that, to extend a deeper tone, they tend to increase the OD more than pushing for longer length. As an example, the longest tubes of their different sets of the same "Quatral Tuning" (compared to OD used) are: Alto=1.5"OD @ 28", Tenor=2"OD @ 39", and Bass=2.5"OD @ 51". Is there some reason for this other than just going a bit longer with the same OD tubing?

I'd kinda like to experiment with really thick walls without breaking the bank, and I haven't been able to find any aluminum tubing with a .250" wall thickness that's not like buying gold. But, if one wishes to get some pretty reasonably priced, reasonably thick-wall, "Schedule 40" aluminum in 20' lengths ($10 extra per stick if you want them to cut it into two 10' lengths for cheaper shipping), I did find some fairly thick, extruded tubing (with medium heat temper) that might be worth playing with at: www.globaltecheng.com

The pricing I saw (less shipping or any desired cutting) for Schedule 40 extruded tubing was:
1.5" OD @ .145" wall thickness (about 1/7") for $1.90/ft.
2" OD @ .154" wall thickness (about 1/6") for $2.56/ft.
2.5" OD @ .203" wall thickness (a bit less than 1/4") for $4.06/ft.
The price for the 2"OD is about what one would pay for 1"OD hard copper from Home Depot; so, it might be worth experimenting with at a reasonable cost for aluminum with a fairly thick (about 3/16") wall.

So, what's the expert opinion on very thick wall tubing? Does the increased degree of performance I heard due primarily to the thick walls? Now I'm really confused!! Brent

 

From:  "Jack Maegli" <jackmaegli@jvlnet.com>
Subject:  Re: Sample Sounds

Music of the Spheres is probably the premier commercial manufacturer out there in my opinion.

#1 Yes, as long as the length to diameter ratio is correct, I think these guys use the same approximate tubing dimensions I do, and when tuned to fundamental do well.

#2 Using the right proper L/D has just as profound an effect on thick as thin. The importance of air column makes kind of an interesting debate as the thickness grows, doesn�t it.

#3 I �think� MOTS uses tubes that are not a constant ��, but rather similar to schedule 40 or 80 (thickness proportional to diameter). They adjust their clapper/sail to provide more force when striking the larger tube sets. Now that I have completely evaded the question, experiments done with very thick material (like bushing stock) have not produced a longer ring sustention than MOTS type, perhaps at some point thickness produces impedance to transverse vibration.

#5 I �think� they are correctly keeping their length/mean diameter ratio constant.



From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: Copper tubing chimes

Jerry;

I've played a lot with various sizes of copper tubing, and really appreciate the unique sound it produces; the choices between going for a highly-polished finish (protected by a thin layer of polyurethane) or a rich patina color broadens the aesthetic options. Of course, I also appreciate the different sound of either steel or aluminum chimes I've built as well. The copper has a more mellow sound that many prefer; while the steel and aluminum have a brighter, louder produced tone that others prefer. Personally, I appreciate the difference in both types of tone and enjoy the diversity of having
different sounding chime sets.

There's only two ways to make copper sound better to my knowledge and experience. First, DO NOT use the commonly found "Type-M" tubing that is usually found in most consumer hardware stores like Home Depot or Lowes. Type-M is the softest of the "rigid copper" tubing and doesn't produce nearly as good a tone as the harder "Type-L" tubing; better yet is the even harder "Type-K" tubing that usually has to be ordered online or from a plumbing supply store. The second thing I've found
is that it's better to stick with either tubing with an outside diameter (OD) of 1", 1.5", or 2" because smaller diameters just don't do as well in produced tone results.

If you don't mind a little extra expense of "putting a wolf in sheep's clothing", you can do like a friend of mine who makes highly polished "copper" chimes from discarded, thin steel, commercial vacuum cleaner tubing he gets from where he works at a carpet cleaning machine company. While you can't start with any steel tubing that's galvanized (unless you want to first remove it), take your good steel tubing to the local chrome shop. If it is already chromed, they can remove it as easily as they electro-plate it by reversing the process in the plating vat. Before any steel is chrome plated, it
must first be plated with a very hard copper/nickel alloy (about 80% copper) because chrome will not stick to steel. He simply has them double-plate the steel chime tubes with the hard copper after he's cut, tuned, and pre-drilled the mounting holes in the tubing. Using a little elbow grease and a can of good 'ole Brasso, he makes them so shiny you can see the cracks of your teeth in them; then he lightly coats his "copper" tubes with a coat of liquid polyurethane. The end
result is copper chime tubes that sound like steel - eureka!! Brent

 

From:  "Jay Shah" <jay_shah@yahoo.com>
Subject:  Chromatic windchimes - our experiment

My two children and I made our first chromatic windchime mostly based on "Making Wind Chimes" by Jim Haworth
(http://www.oocities.org/teeley2/chimeart.html) and information gleaned from this group. There are 16 pipes, from G# to B. Two photos of the chimes are in the "Photos" section of this group
(http://tinyurl.com/2fd7s). There is an mp3 audio clip of me trying out the chimes in the "Files" section of this group at
http://groups.yahoo.com/group/windchimeconstruction/files/. The three songs you hear are Scarborough Fair, Frere Jacque and Twinkle Twinkle Little Star. I used a brass mallet of the type used to play xylophones, to produce the sounds (rubber mallets flatten the sound, plastic mallets are ok).

The project was completed over two days. Some construction information with approximate costs:
The pipes are 3/4-inch type M copper. (Two 10ft pipes, $7 each). A pipe cutter was used to cut individual chimes (cost $10.00).
The pipes hang from a 36"x3"x1/2" block of wood. (Cost $2.00).
The string used to hang the pipes is monofilament fishing line with a 20 lb load rating. (Cost $2.00).
The line holes were drilled in the pipes with a 1/8" drill bit and then 1/8" aluminum rivets were used to stop the line from being abraded by the jagged edges of the drilled holes. (100 rivets cost $5.00). Scotch superglue was dabbed between each rivet and pipe, so that the rivets do not fall out. The string holes are drilled at a distance from the end that is 22.5% of the length of each chime.
The lines hang from screw eyes screwed into the block of wood. (Cost $8.00).
The completed chimes hang off the side of the patio via two screw- eyes and a thin tie-down rope. All material was bought from Lowe's, except the fishing line which was bought from Sports Authority.

I started by cutting a chime of 12" and then using a chromatic tuner (Korg CA30) to check the note produced. However, due to odd harmonic contents, I did not get the same reading each time. So I just assumed it is note C, followed the formula and cut the other chimes, resulting in the largest and smallest chimes of about 15 1/2" and 10". The formula is based on the two facts: (1) adjacent notes in the chromatic scale have a frequency ratio of 12th root of 2, or 1.0595, and (2) the ratio of lengths of two pipes is inversely proportional to the square root of their frequencies.

See Jim Haworth's web page for details.

I did not fine tune the pipes after cutting - it is too laborious, I am not good at measuring frequencies, I do not have scraping tools, and I did not have the patience.

 

 

From:  cllsj
Subject:  Re: Copper tubing chimes

Brent;

You're making this too easy for me to pick on you.

There is no difference between the copper alloy used for type K, L, and M. It is all C12200. The difference is the wall thickness. Maybe I should qualify this and say this is for tubing used in plumbing. Other applications use other alloys. It would appear that it could be obtained as soft (annealed) or hard (drawn). For chimes I would assume we are only interested in the hard form.

I'm now done picking on Brent for today. Chuck

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: Copper tubing chimes

Chuck;

Don't worry about picking on me because I enjoy any enlightenment which helps chase the darkness of ignorance. "Fred" is very good at assessing a noted difference; but, on occasion, is wrong in the assumption applied to explain some unknown aberrancy. I'm glad you did the research that I failed to do because it not only explains a little anomaly I experienced many months ago, but also will possibly help any other members who wish to play with copper tubing - and take the time to read this.

As Jim Haworth has warned many times, it is imperative that anyone attempting to use the charts to figure the proper tuned lengths for chimes made from the same type of tubing should always make sure they start with tubing that's all from the same stock (and/or stock#) and purchased from the same batch to help ensure a degree of uniformity.

You will probably remember my notation of coming up short on enough 1" OD, Type-L copper tubing to complete a set of chimes. After going back to Home Depot and purchasing another 10' length of the "same" tubing (same manufacturer, same Type-L), I noticed that the linear markings on the new tube were in blue ink instead of the fine print that was stamped into the metal on the original stock from the same store. After cutting the new tube to the length, which should have
worked like the others (using the same calculating criteria), I was amazed to find the new tube was a full 5 chromatic steps off frequency from where it should have been. I did some refiguring to compensate for the difference, cut another tube which worked OK in the frequency department but didn't sound as good as the others; I wrote the whole thing off as a difference between different batches of the "same" tubing.

After your comments about only the wall thickness being different between Types M, K, & L copper tubing and the major difference was being the hardness factor between annealed (soft) and drawn (hard) tubing, I went back to the shop to inspect a few scraps I had left over in my junk tube box. Both scraps of tubing had the same stock number (there was no part number); but the first batch of tubing (with the fine print stamped into the metal) had a "D" (drawn) at the end of the stock number, and the last section of tubing I bought (with the inked markings) had an "A" (annealed) at the end of the number.

It's not surprising that the "expert" at Home Depot didn't have a clue as to the difference and neither did Home Depot (because they sold it all at the same price from the same rack designated only as "Type-L"). Surprisingly, I called three different plumbing supply stores before I found someone who could tell me if their 1" OD, Type-L copper stock was drawn or annealed (or even knew what I was talking about) - duh!!

Soooooo, anyone buying copper tubing for windchimes would not only be better off in getting the thicker wall of either Type-L or Type-K, but look very carefully at the tube's markings to find the "D" or "drawn" designator somewhere in the markings or stock number. The harder (drawn) tubing most definitely produces a much better sound than the softer variety.

Thanks again, Chuck. Pick on me some more because it helps all of us. Brent

 

From:  "bmh1944" <bmh1944@yahoo.com>
Damyon;

I've never experimented with the tubular steel used for cyclone fenceposts because, having installed a few fences in my time, I've found there's little consistency in either the wall thickness or steel alloy used to make them. To my knowledge, there is no industry standard on either metal alloy composition or wall thickness like exists for copper plumbing tubing, EMT, and iron pipe; so, the varieties of fence tubing abound. The only common thing I've found in fence tubing is the particular OD (outside diameter) is usually about the same to allow fitting of most available fence mounting hardware
and top caps. I've found some post tubing which was very thick walled and extremely hard, but I've also found numerous others that were thin and fairly soft metal. I suppose the hard, thicker stuff might work pretty well; but I'd think the very thick, cast metal, top caps would create quite a bit of dampening effect. The only capping and top/center suspension I've done has been by either using the very thin commercial caps for hard copper tubing, or welding a flat fender
washer inside the opening of steel tubing.

I supposed that just about any metal tubing or rod that is fairly hard would make a decent sounding chime. The Fred Flintstone method of testing hardness (with something I've pulled from the dumpster, junkyard, or store shelf) is simply using the "tink" method. Using the back of my pocket knife blade or some other very hard metal object, simply tap the material and listen to the sound it produces. A very sharp, high frequency "tink" sound usually indicates something
that's pretty hard. When comparing more than one type of material, the one that produces the loudest, sharpest, highest pitched "tink" is usually the harder material. If you've got a junk knife, a bit of attempted shaving or scratching will also help indicate hardness; but for any galvanized steel, you'll have to get through the zinc coating before actually being able to test the steel underneath for scratchability.

If you find some cheap or free SS tubing, it will make the best sounding chimes you've ever heard; but be prepared to deal with it. My best sounding chimes are made from 1.5" OD, SS tubing that I made a one-time "steal" of a buy from a nearby Boeing surplus scrap yard. Unfortunately, this crap must have had a Rockwell Hardness factor of over 400 because there was no cutting it with a hacksaw, and a new (fairly expensive) drill bit in a drill press only barely scratched the surface. I ended up having to cut it with a carborundum blade in a chop-saw, grinding it smooth, and end-capping it for mounting by using good 'ole JB Weld to glue in a thin steel disk (welding discolored it too much) - but they sound better than anything I've made yet. SS tubing comes in all types; but I've learned that much of it is usually heat tempered (to either lesser or very extreme degrees). So, the ease or effort in working with it will depend on just how hard the stock you find happens to be. Brent

 

From:  "bmh1944" <bmh1944@yahoo.com>
Subject:  Re: Newbie with stainless?

Hi GRAYJ;

Stainless steel probably produces the best sound one could expect from windchimes because it is usually a very hard metal alloy; unfortunately, depending on it's degree of hardness, it can be extremely difficult to work with. Unlike most "annealed" (softer) or "drawn" (mechanically hardened) tubing of most metals, stainless steel tubing is usually heat tempered to obtain a much higher degree of hardness. The "hardness factor" of metals and alloys is typically measured using the "Rockwell Standard" with soft metal being a very low number and hard metal being a higher number.

My memory sucks; but as I recall from a metal-guru friend of mine, here's "ballpark" estimates of what I remember:

1. Hard "drawn" copper (plumbing) tubing = (approx) Rockwell 58

2. Most aluminum alloy tubing = (approx) Rockwell 55 to 85

3. Steel EMT (electrical conduit) = (approx) Rockwell 90 to 100

4. Stainless Steel (depending on manufactured application) can easily have a heat-tempered hardness running from Rockwell 200 to 440.

Applications requiring stainless steel are usually along the lines of high-carbon steel - but much greater resistant to rust and corrosion. Most stainless steel products with holes or other machine work done had such completed BEFORE it was heat-tempered. Depending on the hardness of the tubing you have now, drilling it or hack sawing it may range from very difficult to virtually impossible; so, you may want to first experiment with such close to the end of one of your tubing
sections.

Considering the relatively short pieces of tubing you have to work with (with respect to it's 2" diameter), I'd personally suggest not worrying about cutting or "tuning" each piece to some desired musical note. Windchimes are struck at random anyway; so, as long as each tube is of enough difference in length to produce a noticeably different pitch, Fred Flintstone (yours truly) finds great aesthetics in beautiful sounds, which may or may not be "tuned" to any particular note.

Go to the "links" section here and read Jim Haworth's "Article On Making Windchimes". He has a very simple mathematical formula by which you can cut a tube to ANY length, use it as a "base" to work from, and cut the other tubes to get very close to a (one note at a time) chromatic musical note progression if you so choose. Otherwise, I would personally recommend figuring how many tubes you wish to have in your windchime set, allow about a 2.5" length difference between
each tube, divide up what you have to get the least amount of waste, don't worry about "tuning", and just enjoy the audible aesthetics of their diverse sounds. Brent

In either case, it might be fun to experiment with a little - just to see what does happen. Brent

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: Aluminum Alloy Tubing and Pricing

Howard;

The tubing I mentioned and used from them was Drawn 6063-T832 type. According to the TT listing, the 6061-T6 you have checked out is "extruded" (softer) tubing and not "drawn" (harder) type. They sell the 6061-T6 extruded tube, but only in 1.125"OD and 1.250"OD (.058" wall thickness) at about 20 cents per foot cheaper than the drawn 6063-T832 which they stock in the range of sizes I listed in the earlier posting. Interesting thing I didn't notice before is that they also sell the extruded tubing only in two sizes of 2"OD; one has a .120" (about 1/8") thick wall at $4.50/foot and the other is a very
thick .250" (1/4") thick wall at $8/foot. That's pretty pricey, but many premier windchimes use the very thick wall aluminum.

To be honest with you, I haven't used enough aluminum to give even an experienced opinion about wall thickness; but the .058" to .060" seems to be what many reasonably good commercial chimes are made from. One of the premier chime makers (Music Of The Spheres) uses very thick wall aluminum that goes up to 1/4". Schedule 80 drawn aluminum electrical conduit approaches that thickness in larger diameters, but it is like buying gold and is getting really hard to find anymore because plastic is becoming the electrical contractor's weapon of choice since it is both durable and cheap. Brent

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: Aluminum Alloy Tubing and Pricing

Howard;

Now you see why it is very confusing to "shop around" for aluminum tubing - lol. You are probably correct because I (out of ignorance) assumed that part of the industrial number for a particular alloy would indicate whether it was drawn or extruded/annealed. However, since your source shows both options for the same number, that logically proves that the particular industrial number ONLY indicates the alloy contents and their respective percentages of the whole. For
instance, I DO know that Type-L copper indicates both 99.9% pure copper and a particular wall thickness (about .050"), but that number does not indicate whether it is annealed (soft/flexible) or drawn (hard copper). So, I would imagine that other alloy numbers would be in the same arena with only a manufacturer's stock number or other designation to indicate extruded or drawn.

As for my preference in wall thickness of any tubing, it is a very simple mathematical process: choice of preferred metal and particular wall thickness is directly proportional to the thickness of my wallet at the time. Being a junkyard explorer and opportunist, I've only ordered a particular tubing on two occasions - one of them being the aluminum from TT because the price was good and I wanted to try it out. Otherwise, I've usually pounced on whatever happenstance presents at a good or giveaway price (or chimezilla would have never happened).

Since I don't have the industrial alloy number reference, I don't have a clue as to the actual metal content of either two alloys we have mentioned. While I was online exploring aluminum tubing a while back, I do remember a place my search engine found that gave you access to such information. As I remember, there was no fee involved, but you had to register with them before you could gain access -hmmmmm, sounds like a porn site - lol. Annyway, I'll try to find it again and post the web address if I am successful, it may help anyone else who's also as confused as we are.

I'm not waltzing around your question about preferred wall thickness because I have no preference. I've found beautiful sounding metal with very thin walls and very thick walls, and I've also found crappy sounding metals with very thin walls and very thick walls. Perhaps Chuck or Jack can shed a little informed light on the subject, but I think that it depends on the type of metal/alloy, the OD, the hardness factor, and frequency range at which you tune it which all combine to determine whether the degree of wall thickness can be either an asset or a liability.

I would think that increasing the wall thickness of any tubing would increase both its area mass and degree of rigidity. The higher area mass would require a greater striking force to set it into the same degree of vibration as it would for the
same material with thinner walls; but once in vibration, I would think the higher mass would tend to remain in vibration for a longer period of time. From my experience, the greater degree of overall tube rigidity (by increasing wall thickness or metal hardness) has tended to sustain higher frequencies better because its increased inability to flex poses a greater impedance to, and faster decay of, lower frequencies, which require a greater degree of tube movement. However, once again, the tube's OD and length ratio at any particular frequency is the major factor in what you will hear - regardless of
wall thickness.

From the experimenter and tinker's point of view, I am always highly skeptical of spending big bucks on any kind of tubing with any wall thickness if I can't pick up a piece of it and give it the 3-T test. Just as Maggie found with a piece of square steel tubing; I try to isolate a piece of it, give it an antinode whack with the back edge of my pocket knife blade, and see if I hear a tink, thunk, or thud (the 3-T test). That tells me more about whether it's going to make a nice windchime better than industrial alloy numbers - lol. There are simply too many varieties of aluminum alloy with varied wall thickness for anyone to say what is best or preferred because much of your results is going to depend on the particular frequency range that is the desired target. I would almost bet that any particular alloy has some "happy range" of wall thickness that works best for each particular frequency range (providing one remains within Chuck's "ideal" length/OD ratio for tuning at the first natural frequency). So, it still gets down to a crapshoot of experimentation
with each frequency range and each particular alloy if one is striving for the "absolute best". Many tuning spreadsheets and charts usually base their calculations on .050" to .065" wall thickness, and that is a good place to start without spending major bucks on really thick wall material. Brent

 

From:  "numexjohn" <rosses@cvn.com>
Subject:  Gil's chimes

I want to say something about what Maury Gilburne is doing with his business of providing high quality wind chime kits and other materials.

I've ordered and built five sets of chimes from him now and am extremely pleased with the result. His business is called Wind Chimes by the Inch, and that's exactly what he offers. He has a vast array of sizes of aluminum tubing that he will cut to whatever dimension you want, to whatever key you want, and charges simply by the inch of material. There is no cutting charge, and there is never any waste.

Maury (call him Gil) cuts each tube just a tiny bit long for each note. With a very small amount of grinding you can bring each chime right to the desired final frequency. In the chimes I've built from his sets, I've yet to find one more than 20 Hz off the nominal frequency upon arrival, and usually they're more like 10 Hz off, making it extremely easy to grind and sand it down to the desired note. I use my bench grinder to get it within several Hz of the note and then get even closer with my disk sander. My finished chimes are as accurate as my Korg tuner can make them. If you're not into high-
precision tuning, however, all the tubes he sends are close enough to the designated note to sound great as is.

Gil gets his tubing directly from the mill, and it has a wall thickness of .063 inches, resulting in chimes that resonate on and on. I've found most of them will resonate 40-50 seconds after being struck. In a moderate breeze when most of the chimes are being struck, the resulting sound is like that of an organ.

Gil sells all the accessory items, too, and you can check everything out on his developing website, www.windchimesbytheinch.com. He is providing a real service for us chimers, with everything at competitive prices.

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Copper/Brass vs. Aluminum

I fully agree with Chuck in not wasting time with thin, Type-M hard copper; the thicker Type-L is pretty fair, and the thicker (usually must be ordered) Type-K is best.

If you've got some 2"OD Type-L or Type-K hard copper plumbing tube, then you can get down into the high C4/low C5 "ideal range" at the first natural frequency.

Personally, I enjoy using both aluminum and thick-walled copper or brass; but it depends on what I am trying to achieve in either visual or aural aesthetics.

Visually, aluminum can be either highly polished and thinly coated with outdoor polyurethane spar varnish to preserve the shine, or left to weather into a dull silver color. Copper and brass can also be polished and coated, or left to weather to a dull rust/red color in relatively clean air conditions - or to a nice blue-green patina if you live in a large city with tons of corrosive crap in the air.

As far as tone aesthetics go, that is another matter of personal preference. One area of personal preference is that hard copper or brass has a softer, mellower tone than aluminum in relatively short chime sets of smaller ODs. However, in another area of efficiency, I've noticed a distinct difference between copper and aluminum at the higher and lower ends of the audio range � especially when using ODs larger and smaller than 2".

From some of the sets I've cranked out using very similar wall thicknesses, my vote will always go for aluminum at 2"OD and less because (being more rigid) it seems to sustain the higher frequencies for a longer period of time. Yet, when using ODs greater than 2" to push the length and tone down into C4 or lower (tuning at first natural frequency), I've found the thick-walled copper seems to quickly attenuate the higher overtones, and sustain the lower fundamental longer than aluminum.

I think a tube's rigidity factor has a considerable influence on whether it sustains higher or lower frequencies better. Using the same OD and wall thickness, a copper or brass tube will flex easier than most aluminum alloy tubing; so, with respect to length (as with the transverse mode) the copper will flex easier and to a greater lateral degree with the same applied force as the more rigid aluminum alloy will. Even though the copper and aluminum tubes may be tuned to the same resonant fundamental, the higher degree of cross-sectional rigidity will create a considerably higher degree of opposition to the greater "bending degree" required of lower frequencies than those of higher frequencies which do not require the same degree of lateral movement during vibration. Likewise, the less rigid tube would be more like a limp rope that would easily sustain great degrees of cross-sectional bending motion, yet quickly dampen higher frequencies which need a more rigid environment to sustain.

I suppose I would give an analogy to copper and aluminum as comparing them to the large, relatively soft, cone of a bass speaker (with a great degree of "throw" or lateral cone movement) to a mid-range speaker's smaller, more rigid cone, with a lesser degree of lateral cone movement. Feeding a high tone and very low tone to both speakers would see the very flexible bass speaker move very easily and efficiently with the greater degree of movement required by the lower frequency - yet attenuate the high frequency to almost nothing. The more rigid mid-range speaker would have a higher degree of cone
rigidity that would respond well to the high frequency's "short throw" requirements, but lack the high degree of free lateral movement to do much of anything with the lower frequency.

Whether based on fact or not, my radically different chime sets seem to prove this theory. In smaller OD, shorter length sets, the copper is very mellow sounding because it's lesser rigidity is quickly dampening the higher frequencies that find a very nice environment in the more rigid aluminum or steel tube; yet in the very long, very large OD sets, the copper really sustains a beautiful deep timbre much longer and louder than the aluminum sets have done. In either case, it still gets down to personal preference in both visual and aural aesthetics as to which is really best. Beauty is truly in the
eyes and ears of the beholder. Brent

 

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: Copper type question?

Hank;

If there is no inked or metal stamped printing on copper tubing, there's no telling what you have without using a micrometer to measure the exact outside diameter and wall thickness. All plumbing "types" of copper must be marked along the entire length of the tube when it's originally sold; and, depending on the particular "type" designation, the wall thickness increases with the tube's OD. The inked-on markings usually stay pretty well unless someone has purposely removed it with steel wool or lacquer thinner; of course, the markings which have actually been die-stamped/rolled into the tube metal will always be there.

I've noticed that many manufacturers will ink on the most commonly used Type-M tubing (not good at all for chimes in sizes of 1" or less in OD), while they will often metal-stamp the higher spec Type-L and Type-K tubing. The first thing to do is make sure you have "hard" (drawn) copper which almost always comes in straight lengths.
The "soft" (annealed) copper usually comes in a roll, and is only suitable for makeshift plumbing repairs and constructing windthuds. If you have any "hard" copper tubing that has no exterior markings at all, then it is most likely either Type-M or a non-plumbing grade of copper.

As long as you have hard copper (drawn tubing), there is very little difference (if any at all) in either the hardness factor or metal composition because most all copper tubing is 99% pure copper, and the drawing process creates about the same degree of mechanical hardening to the tubing. The greatest differences between the "types" of copper tube will be the wall thickness; Type-M will have the thinnest wall per OD size, Type-L will be thicker, and Type-K the thickest. From what I've noticed, any copper tube with a wall thickness of less than .050" does not make good chime material at all.

Since I have not experimented with plumbing grade Type-M in diameters of 2"OD or more (where wall thickness would become .050" or greater), I can't honestly say if Type-M would become "acceptable" with thicker walls in the larger diameters. Brent

 

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: Tube Spacing

To my knowledge, there is no "formula" for tube spacing or relative clapper diameter - only a lot of "rule of thumb" concepts that seem to work pretty well.

Spacing the tubes depends on both the diameter of the tubes and how many of them you'll be putting into a set of chimes. I usually end up taking short pieces of scrap tubing or flat washers (that are close to the tube diameter I'm using) and laying an appropriate number of them out on a table to experiment with spacing them properly.

Normally, if your tubes are less than 1" apart, their lower ends will bang together frequently in moderate wind. For the same reason, the spacing between them may have to increase for tubes over 3 feet long; but I've never exceeded 2" between tubes of any length or diameter.

For most chime sets, the clapper disk should normally hang so that it is about 3/4" from any of the tubes in the set. Any greater distance will take a lot of wind or an unusually large sail to move the striker far enough to hit a tube, and any closer distance won't allow enough striker movement to produce adequate momentum for a good hit.

Another rule of thumb is to have your tube spacing and appropriate striker diameter matched so the striker will usually only hit one tube at a time - e.g. a large diameter striker disk would hit two or three small diameter/closely spaced tubes regardless of which direction it moves.

I usually lay out the short tubing scraps or washers (to represent the number and OD of chime tubes I'll be making) in a circle on a piece of paper - then space them about an inch apart. I'll use a simple compass to draw a circle (to represent the striker disk) inside the tubes, and make it of a diameter that will be 3/4" from the inner walls of the tubes. Then it just gets down to increasing the tube spacing a little (and proportionally increasing striker diameter for the same 3/4" clearance) until I can see that the striker will usually only contact one tube at a time unless it heads right between two of them. Brent

 

 

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: node location- 2nd harmonic?

Joe;

Brew gave you an excellent answer that I hope takes you on to Chuck's site (as he recommended) for a little more technical insight to pass along to your students. If you get a little bogged down or confused with much of the complex physics and mathematics that goes on in a resonant tube or rod, Fred Flintstone can give you a elemental idea of how the fundamental transverse vibration mode in a relatively uninhibited (node-suspended) tube or rod would look if you could see it in action.

While many different physical properties of a tube or rod will determine what particular frequency will find a fundamental
transverse mode resonance in a given length of the medium (tube or rod) used, the length of that particular medium will be equal to one-half the full wavelength of the resonant fundamental frequency.

I will greatly exaggerate the actual movement, but it helps to relate my stone-age description of such. Grasp both ends of a straight length of flexible rod or a piece of stiff wire; this is the tube or rod in its normal state. When it is struck by a relatively hard object, it will initiate vibrations in many modes (directions); but the transverse mode (that runs lengthwise) is the one we hear the most. Now, slightly flex the rod to make a very gentle curve downward (to make a happy face smile), lay it on a piece of paper or chalkboard, and trace its outline; that will be the first half-cycle of the fundamental transverse mode. To graphically create the next half-cycle, make the same degree of bend upwards (to make a frowny face), then overlay it with the previous curve so that their intersecting points (near both ends) will be .2242 of the total rod length - then trace that outline as well.

As you can imagine, this fundamental frequency will cause the tube or rod to flip-flop back and forth with overlaying wave shapes which intersect at a distance of .2242 the overall length from each end. You can see that both ends and the middle of each curve represent three areas of maximum movement (antinodes) with each half-cycle of vibration, and the two intersecting points are both areas of minimum movement (nodes). By looking at the simple diagram, it is easy to see that suspending the tube or rod from a node point (of minimum movement) will pose the least amount of interference (dampening) to the sustained vibration of the tube.

Now you need to get this basic concept planted in your mind, then go to Chuck's website and do your homework because I happen to be married to a school teacher - and we're gonna go over and over this again and again until ya' get it right - LOL. Good luck with the project. Brent

 

Anyway, the 150 pound test rating for this very fine 1/32" diameter cable is doing just fine for now because I'm not really aspiring to do any more 100+ pound tubes in the near future. It nice to know that we are both on the same page when it comes to using cable suspension for anything that rises past the "sissy range" of short, light, almost insignificant little pea-shooters hanging from momma's sewing thread - and grows long, wide, and heavy into the manly arena of "cojones chimes". Brent

 

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: Stainless Steel

Brew is correct on all fronts because stainless steel is not enough different than many other types of steel to worry much about getting the correct length. Just use Chuck's calculator and stay within the "ideal range" for steel tubing's dimensions you have, and remember the ID is going to be the OD minus twice the wall thickness.

I've not personally made any chimes from stainless steel, but I've worked with ss tubing and sheet metal in times past. Most of it I've messed with usually has a fairly high temper and is considerably harder than most common steel like that of EMT electrical conduit. Brew is right in the fact that I've found most stainless steel extremely difficult to drill and cut because it's usually quite a bit harder metal.

My only advice there is to use an extremely high quality, very fine-toothed hacksaw blade and use long slow strokes when sawing it. Drilling it is about the same degree of difficulty, and I'd recommend using a very sharp tungsten drill bit with fairly hard bit pressure and extremely low speed. If you're going to drill any hole over 1/8" in diameter, I'd suggest drilling a 1/8" pilot hole first, then use the same drilling technique to step up in hole size with the larger bit(s).

I've heard some ss chimes before, and they really sustain the tone for quite a long time. So, while it's considerably more difficult to work with and extremely more expensive than most other tubing, it makes great sounding chimes.��� Brent

 

From:  "Brent" <bmh1944@yahoo.com>
Subject:  Re: Stainless Steel

Doug;

Unfortunately, any wisdom I may have with stainless steel is very limited; but much of your ease or difficulty is going to depend on the hardness of the particular tubing you have. Most stainless steel starts out as being relatively higher carbon steel (which makes it a little harder) than the lower carbon steel normally used for EMT, cold-rolled, and other softer steel products; then there's at least a 10% chromium content alloyed in to make it resist rust and corrosion.
Except for very rare instances, almost all SS tubing starts out as extruded seamless tubing, then drawn to some exact size, then heat tempered to a wide range of different hardness levels to meet some highly specific industrial or commercial application.

Since SS tubing is still considerably over 80% iron, there's no considerable difference in using frequency/length calculations for EMT or any other kind of steel. The degree of difficulty you have in cutting or drilling your particular tubing is going to be experimental in finding out just how much your stuff has been tempered. I've had some SS material that wasn't too big a problem, but I've also had a little experience with some stuff that was like trying to drill or cut a saw blade.

Personally, I prefer trying to cut it with a hacksaw first because it creates the least heat and fewer burrs to remove. Try getting a good bi-metal type hacksaw blade with at least 24 teeth per inch (32 teeth is probably better) and see if it will work on the SS tubing you've got; if it does, you're good to go. If it's too hard and the hacksaw blade barely scratches it, then grinding or using an abrasive bladed chop-saw is about the only other option when you don't have a nice
expensive plasma cutter around. You're right in keeping plenty of dunking or dousing water around because too much grinding or abrasive cutting heat can case harden the stuff to the point it laughs at a good file.

Gently grinding or filing is all that's required to deburr and smooth the end of a really hard tube. The best way to avoid a lot of length trimming and frustration is to forget about obsessing with hitting the exact textbook defined frequency for some particular musical note (using any frequency measuring device). Simply use Chuck's calculator for steel, figure your tube lengths for the "first" natural frequency (for your particular OD and ID dimensions), and keep within the "ideal range" of lengths. If you cut all your tubes to those calculated lengths, they will be "in tune" with respect to each other
and sound great.

The big thing to remember is that excessive heat is your worst enemy with SS; not only will it tend to case harden it to a point of being nearly impossible to work with, but it will also install a dark blue patina that's hell to ever polish out. If your hacksaw won't cut your tubing, then here's a good trick for using your chop-saw and an abrasive blade without making a major mess and creating excessive heat. First, shop around for the very thinnest abrasive blade you can find for your chop-saw. Cover the base of the chop-saw with visqueen or any heavy plastic trash bag. Tie a strong cord to the handle of your chop-saw, pull it down to where the blade is pretty close to the base, and secure the other end of the cord to the base to hold it in that mostly-down position.

Next, take one of the wife's old bath towels (that you've already had a major butt-chewing from staining), thoroughly soak it in water, and lay it thickly folded on the plastic covered base of the saw. Use a piece of masking tape around the tube as a guide, and either scribe or use a fine-tipped magic marker to strike a cutting line around the tube - then remove the tape. Lay the tube on the water soaked towel, and hold the tube with both hands at a safe distance from each side of the cutting line. Rather than just pushing the whole thing into the blade like feeding a piece of wood through a table saw, push the tube up to lightly contact the blade, then begin gently rolling the tube so the blade runs along the line you've scribed. By using gentle pressure and keeping the tube rolling, you won't create a lot of frictional heat and the wet towel will keep cooling the tube as it's being rolled. It may take two or three complete tube revolutions to make your very light blade contact finally cut completely through the walls (like a pipe cutter); but the tube won't overheat or discolor,
and you'll have a lot less burr to remove over what you'd have by just punching the abrasive blade quickly through the tube.

Drilling will take a very sharp tungsten bit, running at very slow speed, with a little WD-40 frequently used to lube and cool the cutting surface. Hope this helps.��� Brent

 

From:  "Archie" <archie97@earthlink.net>
Subject:  Re: Stainless Steel

No problem grinding aluminum.
To keep the particles small, and prevent grinder clog, coat the wheel with beeswax, and apply a bit at a time as needed.
Archie

 

 

 

 

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Updated 3-24-05