VARYING THE PITCH OF TUBULAR ALUMINUM WINDCHIMES Art Hunkins abhunkin@uncg.edu www.arthunkins.com Revised: 5/30/12 Addenda added 9/4/16 Have you ever wanted to change the scale of your chimeset? Or experiment with tweaking their pitch? Or perhaps tune chimes in near-unison to create different beat patterns? Now you can. The secret: hose clamps - either "spring action" (steel), or "Herbie" (nylon). [Please see Addenda below for a two additional methods. The third method is both less expensive and its thin-walled PVC considerably easier to work with. However it permits less variation in pitch, and shortens ring time. The fourth is a less aesthetic variant of the initial method.] Placing a clamp at the end of a chime can vary its pitch by up to a whole tone. A clamp at each end doubles this range. Advantages: clamps do not appreciably alter tone or ring time. Although appendages protrude from both types of clamp, a hit to a flange or clamp rings like a hit to the tube. (To avoid such hits, use only an *upper* mount clamp.) Limitation: pitches can only be adjusted downward. The amount of pitch change is dependent on how far the clamp is from a node (nodes are located 22.4% of the way from each end). When a clamp is at a node, the pitch does not change; placed at tube end, a clamp produces the greatest change in pitch. This is true at both ends of a tube. Here are pitch-variation details for a 1"OD chime, about 1/32" thick (from Lowe's), 1" Hillman (spring action) hose clamp at each extremity: short chime, two tones lower; medium length, 1.5 tones; long tube, one tone. (One tone = two half steps, for example, C to D.) Pitch variability also depends on chime thickness: 1/16" walls reduce the above range by 50%. Greater clamp mass, though, moderately *expands* this range, up to 50%, leaving tone or ring time unaffected. Also, multiple clamps can be placed at the extremes, with a comparable expansion of range. The principle: As Chuck of Chuck's Chimes [see footnote] aptly puts it, "Yes, you can change the response of any tube, aluminum, steel, plastic, wood, ..... by adding weight." This is what we've done. (Longer tubes, thicker tubes and larger diameter tubes all produce lower pitch as well.) Regarding pitch and added weight, however, there is a caveat: adding weight at a *node* does not lower pitch; the greatest pitch change occurs only as you approach the end antinodes. As noted above, two varieties of hose clamp are best for tubular aluminum windchimes: spring action hose clamps (steel), or "Herbie" hose clamps (nylon). Each has its pros and cons. SPRING ACTION HOSE CLAMPS (steel) Pros: *Spring action hose clamps are readily obtained in 1/2", 3/4", 7/8" and 1" sizes from Ace Hardware and Lowe's (but not Home Depot). They are manufactured in the US by the Hillman Group. *These sizes can be purchased in quantities of one or two. *These clamps are heavier than their nylon counterparts, and are thus capable of wider pitch variation. (This is especially true of larger sizes.) *Once installed, it is not difficult to adjust tuning (though pliers are required). Cons: * Considerably more expensive than nylon clamps. * Require slip-joint pliers with a stout (preferably 1/2" thick) jaw for installation, adjustment and removal. * Larger sizes are harder to locate; I've largely found them on eBay. Only available in lots of 10 (5, for largest diameters). * These larger sizes have flanges that protrude twice as far as Hillman clamps. They are ugly. * Those sold by autofittings (eBay) and imported from China, are not recommended. Their sizes can be inaccurate. They also break readily, and represent a safety hazard when they do. * To be safe with these larger steel clamps, acquire a set of flat band hose clamp pliers. They eliminate most of the hassle (and danger) associated with larger clamps, and can be found at many auto supply stores and on eBay (<$10 - $20). * Even the Hillman clamps can be dangerous, however. They can easily slip off pliers. I've lost control of a Hillman a number of times; it has landed up to 15 feet away. Thankfully I haven't been in the way. * If your chimes are center-hung, and the cord is not detachable at top, you can't readily mount an upper clamp. If you opt for larger steel clamps, there are two decent choices (though I hesitate to recommend either): 1) "Constant Tension Band Hose Clamps", available on the web either through the Page Auto Supply store on eBay, or their clipsandfasteners.com website. (The manufacturer is Auveco.) One size handles both 7/8" and 1" chimes; another, both 1 1/2" and 1 3/4" tubes. Unfortunately, there is nothing for 1 1/4" or 2" chimes. 2) Rotorclip "Constant Tension Band (CTB) Hose Clamps", also called "Rotor Clamps." Sizes for all tubes, including 2.5"OD+. See the rotorclip.com catalog. Grainger.com carries some of their clamps, including 42mm and 50mm - good for 2" and 2.25" chimes. Grainger's website is great for on-line ordering; there's even an option for customer pickup at Grainger stores (these clamps are usually not in-stock). Also: at rotorclip.com, under "Online Services", you can "Request Samples." I received samples of three asked-for sizes. "HERBIE" HOSE CLAMPS (nylon) Note: Herbie hose clamps have *two* rows of teeth ("double grip"). Other nylon hose clamps (otherwise comparable) have only one; the latter are called "Quick Assemble Hose Clamps" (Alliance-Express) or generally "Single Bond Nylon Hose Clamps." (They are also known as "Plastic Snapper Type" or "Snap Grip" hose clamps; when manufactured by Tefen Plastics, they are made of acetal resin.) The single-bond style requires pliers to install and remove, is more difficult to work with, and seems not to get quite as tight a fit around the chime (crucial to maintain ring time). Pros: * Much less expensive than spring action hose clamps. * Available in a complete range of sizes, through 3 1/4". * Often, pliers not required for installation, adjustment or removal. * Following initial installation, clamps can usually be slid off and on without adjusting or undoing clamp. * No upper mount (center-hung) limitation. * No safety concerns. * Larger nylon clamps are not as ugly or intrusive as steel. Cons: * Only available online and in lots of 10. * Larger diameter clamps, being lighter than steel clamps, offer less variability in pitch. (As nylon clamps are narrower, however, multiples can be placed in nearly the same space as a single steel clamp). The best, and most reasonable source for Herbie clamps is rotocon.com. They've an excellent and straightforward on-line store. Payment is via PayPal. Shipping is fast and reasonable. All sizes are in-stock, through 3 1/4". There are two pricing options: 1) total cost including shipping; 2) basic cost with *actual* shipping billed separately (hours later). Rotocon is located in New Jersey. As I'm also on the East Coast (USA), and ordered *two* 10-packs, I saved on shipping with option 2. In addition, Rotocon offers three appealing options: 10-packs of either assorted small, medium or large sizes. Their medium assortment (one clamp per size) covers all tubes from 7/8" through 1 3/4"! (Indeed, two clamps will work for 1"OD, two for 1 1/2", and two for 1 3/4"!) Rotocon's assortment packs are also available through eBay; search on "Herbie clips." The prices are a bit higher there, and 10-packs for a specific chime diameter are absent. It is important to get a snug fit with Herbie clamps; a loose fit will markedly cut (dampen) ring time. Get the clamp "finger-tight" first, then if not snug enough, add "one click" with the pliers. If you are fortunate, you'll have a sufficiently snug fit that the clamp will slide off or reposition (as well as reinstall) without pliers. You can keep the clamp this way indefinitely (unless you need to extricate it from a center-hung cord on a top mount). Note: Alliance-Express.com will happily send you free samples of their *single-bond*, "quick assemble" nylon clamps. Indeed, you can order clamps in any quantity you like (minimum $15 order). These clamps are *very* expensive however. (Including shipping, you'll pay much more for a single clamp from Alliance-Express than for 10 Herbie's from Rotocon.) A final comment: It is bothersome to keep removing and reinstalling clamps (particularly the steel ones). Recommendation: just park the clamp at the node (or just above the upper node) to "deactivate" it temporarily. It's relatively easy (as well as safe) to adjust position once a clamp is mounted. Here's to happy clamping! ADDENDUM1: A third, easier method - involving short lengths of thin-walled PVC tubing In general, the performance of this method parallels the first two. As mentioned previously, its limitation is that it allows for somewhat less variation of pitch - probably due to its lighter weight. Nonetheless, it is still quite workable - especially for tube walls less than 1/8" thick. (At 1/8" thickness, both pitch variation and ring time fall off substantially.) An obvious advantage of this method is that it is easy to attach the PVC at the top of a center-hung tube. The method applies most feasibly to chimes 1" and 1.25" in diameter, as thin-walled PVC tubing is only readily available up through these widths. (Lowes carries these sizes; Home Depot does not.) Larger diameters through 4" are available online, however - notably at FlexPVC.com (search for Thin-Wall Class 200 PVC Pipe). Cut 1/2" segments of the PVC with a miter saw or box, or PVC or aluminum pipe cutter (warning: thin-walled PVC is difficult to work with a cutter). Any tool that gives a straight, smooth cut will do. Segments other than 1/2" are also useable, though those less than 1/2" tend not to stay put, and longer ones are more difficult to move around. Next, use a set of PVC or aluminum snips to remove about 1/4 of the circumference of the PVC. You are now ready to go. Since a tight fit - as seen with the two methods above - is necessary to maintain ring time, you'd think that a thin PVC slit might get better results than removing a larger portion. Such is not the case however; the 1/4 removal gives virtually the same ring as a slit and allows the PVC to insert, remove and slide much more easily. For each *short* chime, you will need a single segment at one or both ends (antinodes). For longer chimes, twice the segments are required. In either case, the total pitch change is one tone (1/2 tone if only one antinode is used). Adding further 1/2" segments of PVC will not notably continue to lower pitch, and ring time will only be further reduced. It does not matter at which end you position the PVC, or if you do it equally. The limit is that you can get no more than about 1/2 tone of pitch change at either end. As with the other methods, pitch variation is controlled by moving the PVC from antinode toward the node. Parked at the node, the PVC will not vary pitch, nor will it notably lessen ring time. Since the PVC moves easily, pitch can be fine-tuned quickly; even beats between chimes can be adjusted with minimal effort (and no hardware!) A final word of caution: Ring time reduction is an unfortunate byproduct of this method. The more the pitch is lowered, the less ring you get. The loss can be up to 50%. Here, modest pitch alteration guarantees the best result. ADDENDUM2: STAINLESS STEEL (ADJUSTABLE) CLAMPS This is a variation on the Spring Action Hose Clamps method above and is comparable in cost. Features are also comparable. Pros: *Far easier and safer to adjust than Hose Clamps. *Same extended range as Hose Clamps (though sound is more stable when pitch not lowered to maximum). *Can be used (though not easily) with center-hung chimes whose cord is not detachable at the top. *Readily available locally, for a wide variety of tube diameters. Cons: *Probably the least aesthetic method. *For best results, clamps are required on both ends of tube. *A hex nut driver (5/16") is needed for easy adjustment (a slotted screwdriver works, but is far more trouble). As with the two main methods above, clamp size is dependent on tube diameter. Although one clamp will accomodate a variety of diameters, it works best at the *top of the clamp's range*. (The clamp seems to get a more uniform grip on the tube in this case.) A more equalized grip is also obtained by placing a clamp on each end, with screw mechanisms pointing in opposite directions. This results in purer pitch and tone quality. At Lowes, these clamps are purchased in packs of two, and for the most frequent size (3/4" - 1 1/4"), lots of 10. (The 1/2" - 7/8" size is also available in lots of two or 10.) Cost is $1 or less per clamp. Footnote: Two windchime websites are particularly helpful and comprehensive. Chuck's Chimes - https://sites.google.com/site/chuckchimes/ - concentrates on the "technical stuff"; it details the physics and mathematics of chimes. Lee Hite's site "Say it with Chimes" - http://leehite.org/Chimes.htm - tells you everything you might ever want to know about chime construction; it includes copious examples, links and illustrations.