FURTHER EXPERIMENTS YIELD "MINI-tambiro" Been rapping and tapping on everything of late. My most recent success is a miniature version of the tambiro but instead of an empty helium tank, I used a small, camping-type propane tank (the "squat" type measuring about 3-3/4" diameter by about 7" tall). Using this small cylinder is my idea -- inspired by the helium-tank (freon-tank) tambiro mentioned elsewhere on the internet. The results have been quite successful. It sounds VERY nice & is much fun to play. The main difference between it and the larger helium-tank version (aside from being pitched a lot higher) is that it's not played by tapping, but rather by plucking with the fingers kalimba-style.
I have some misgivings putting this thing on my webpage because of the highly flamable nature of propane. I hereby disavow any responsibility for any harm that may befall anyone tinkering with propane tanks. I will only tell you what I did to make this thing. I do not suggest that anyone else make one. Here's what I did to ensure that there were no "accidents": - I first looked for a tank (stored with my camping gear) that was nearly empty (the liquid propane can be felt and heard rolling around inside the tank when shook). - Then I screwed on a propane torch head, took the thing out in the woods, far from my house & turned the torch valve on full (unlit of course) - it was easy to hear the gas wooshing out. Even tho the tank was almost discharged, it took a while before it was completely empty (it stopped hissing). Connecting the tank to a Coleman stove (etc) would have worked as well. Repeating: I did this OUTSIDE - well away from my (or anyone else's) house. - Once absolutely sure there was NO HINT of gas hissing out and that nothing was heard sloshing about inside, I unscrewed the torch head & using a foot-long "J" bent-up from a clothes-hanger, depressed the "valve-stem" -- a few seconds of hissing was noticed, then silence. Now I knew the tank was really empty. Then I took a HAND drill (not wanting to get a sparky electric drill anywhere near potential propane vapors), with a 1/16" bit & carefully drilled a hole in the top of the tank near the screw threads. No problem at all. I then redrilled the hole to 1/8" diameter. - Next I mixed up a heavy solution of hot dish-detergent & water in a utility pail, submerged the tank in this til it was nearly full (because the drill-hole is so small, this took some time), madly agitated the thing for a few minutes, let it drain & dry overnight. This also served to considerably lessen the LP smell. - Finally, I felt better about tackling a tank that previously held liquid propane! Way over-cautious I know, but .... Concerning tongue size, shape and placement -- I just shrunk down the template shown in my "Helium-Tank Tambiro" article and applied these dimensions to the mini-tambiro. Truthfully, not much is critical - except the LENGTH of the tongues. In other words, just about any tongue size, shape and position similar to what's shown in the photo, can be easily brought into tune simply by CAREFUL and SLOW lengthening the two saw-cuts ends. As with the helium-tank tambiro, the pitch moves VERY fast with even a very small tongue lengthening. After having made several varieties of this instrument, I now try to make the high A tongue a bit narrower -- This seems to help the tone. A note here concerning how I narrowed the width of the sabre-saw blade used to cut the tongues in this instrument -- The blade as-is was too wide to make the necessary tight turns when cutting the tongue. Seems to me I saw narrower blades sold somewhere, but can't find them around here. What I did was to clamp the blade tightly in a vise-grip and (using my hand-crank grinding-wheel which I find is much more controllable than a motorized grinding wheel) slowly ground off about half the width of the back side of the blade, taking care that the mounting end remained untouched. Obviously, the narrower blade could break more easily but with much care and EYE GOGGLES (for both the grinding and the subsequent tongue-cutting), this method worked fine for me. My instruments are normally made of wood and (despite once working as a tool and die maker) metal instruments are a bit foreign to me, so I take extra precaution and time when working anything metal. I notice two different types of squat camping-stove type propane tanks. One has an easily removable plastic bottom-cap that enables the tank to stand upright, The other has a not-so-easily-removable metal cap tack-welded to the tank bottom. This second version is what I used. I had to work at it to get the metal bottom-cap off -- not to mention having to be constantly aware of the jagged edges produced in the removal process. A note about playing -- the tone and sustain while holding the instrument flat in the palm of my left hand is radically different than the tone/sustain if the thing is left unsupported along the bottom side (held against my chest & just the top, threaded part grabbed with my left hand). I like the tone with the first method a lot better. The 2nd method is louder, but contains some undesirable overtones and ringing that is not at all present when held in my left palm. Varying how the tank was held in my left hand resulted in a wide variety of tones/sustain. This mini-tambiro is pitched in the key of C. It's notes are: - low C (do) (middle-column, bottom row) - D (re) (middle column, top row) - F (fa) (left column, top row) - G (so) (right column, bottom row) - B-flat (Ti-flat) (right-column, top row) - high C (do) (left column, bottom row) This is the same scale (but in a different key) as my "full-sized" helium-tank tambiro described on my web-site. While I noted this scale on several of the instruments I found on the internet, I also found tambiros using other scales. On another one I built I pitched the thing a couple of notes lower, with good results. ..................................................... Dennis Havlena - W8MI Mackinac Straits, northern Michigan 3/26/07
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