Rare, 200 year old Zelkova Wood (Akagi) -aged for 5 years -giving a 9% moisture content!
Why Is A Hollowed One-Piece Drum Subject To Crack?
The cylindrical shape of a one-piece drum is inherently fragile. Therefore, we have adapted a new method: we have found the answer in “vectors.”When the force FN(newton) is given vertically against a curved surface, it branches off into f1, f2, and f3.The force f1 and f2 run along straight forward, while f3 runs through the curved surface, thereby causing a crack. (See fig. 1) However, our original global shaped drum shell will disperse the given vertical force along the global surface. (See fig. 2) Hence, we have achieved the desired outcome: a hollowed one-piece drum that is much stronger and more durable than the existing cylindrical surface of the present one-piece drums available.We allow the wood to season naturally for 3years and then treat the shell in a specially designed wood drier to reduce the moisture content down to 9 percent. This drying procedure contributes to minimize the shrinkage and cracking of the drum shell.
A new revolving height adjustable tubular lug
The Zelkova drum features a hollowed one piece shell made from a stump of precious 200 years old Zelkova wood. The wood is seasoned for three years and moisture content is regulated down to 9 percent in a specially designed wood drier . However, this shell may still be affected by outside humidity, and may display a degree of contraction and expansion. The diameter of the shell increases when the humidity is high, and decreases when humidity is low.Since commonly used lugs have a swivel feature to accomodate the tension bolts, it wouldn’t matter if the drum shell expands or contracts. However, the Canopus tube lug has no swivel feature – it is a solid structure in order to enhance vibration cycle efficiency. Sometimes, when expansion and contraction occurs on the shell, perfect alignment of the tension bolts and lugs may prove difficult A new revolving height adjustable tubular lug has been designed in order to solve this problem. It has a mechanism which enables the user to adjust at the height of the lug by plus or minus 2mm by simply turning the center pole.