Photos (2) – New roll reader – spool box
Development of the new roll reader began in 2006, based on modular components. Photos of each spool box module are shown, with a brief description.
Re-roll and braking. Controlled by a separate circuit board, a specially selected DC motor applies user-adjustable power to the supply spool to rewind a roll. The motor also provides proportional braking to the supply spool during play.
Roll drive motor. A high speed 12 V DC motor fitted with a tacho generator provides the motive power to the take-up spool through a 500:1 gearbox. Roll tempo is displayed as shown on piano rolls. Automatic deceleration is incorporated, if needed.
Tracking system, in which the bar is moved to maintain alignment with the roll. The sensor section (left) attaches to the tracker bar and connects to the electronics. Two spring-loaded ears rest against the treble edge of a roll and a thumbwheel adjusts the mechanism to align the bar to the roll. Three opto-sensors provide signals to either move the bar quickly or slowly (typical) to correct any misalignment.
New roll reader
Take-up spool. The roll reader has two take-spools, a standard 6 inch circumference spool and a 70 mm diameter spool as shown. The 70 mm dia spool is used in virtually all cases, as this diameter comforms with most of the recording setups used by the piano roll companies. The spool shown was constructed from PVC tubing and incorporates adjustable spool ends and an embedded and moveable hook to allow tabs to lie in a recess.
Above modules in spool box. The three motorised modules are interconnected such that reroll can only occur if the tracker ears are retracted, play cannot occur during rewind, and braking can only occur during play. The photo on the right shows the modules installed inside the treble side of the spool box. A separate power supply provides the various DC voltages required.