Rolling is a fabricating process in which the metal, plastic, paper, glass, etc. is passed through a pair of rolls. There are two types of rolling process, flat and profile rolling. In flat rolling the final shape of the product is either sheet (thickness less then 3 mm) or plate (thickness more than 3 mm). In profile rolling, the final product may be a round rod or other shaped bar. Rolling is also classified according to the temperature of the metal rolled. If the tempreature of the metal is above its recrystallization temperature then the process is termed as hot rolling, If the temperature of metal is below its recrystallization temperature the process is termed as cold rolling.
Rolls are used on other percussion instruments such as the marimba and xylophone to sustain the sound, where it can be likened to tremolo on string instruments.
The open roll (or "double stroke roll")is played with double strokes alternating between the left and right hands; the closed roll is produced by applying slightly more pressure to the fulcrum upon impact which allows for the stick to bounce many times on the drum head.
Due to the instruments' resonance, a fairly open roll is usually used, although the exact rate at which a roll is played depends greatly on the acoustic conditions, the size of the drum, the pitch to which is it tuned and the sticks being used.
Feeds |
Contact