This could be called the precursor to the Studio-Pro Model B. turntable (there was NO Studio-Pro Model A). The unit is a Russco Studio-Pro B.I.D. "Belt-Idler-Drive," and is considered as the first "STYLE" of the Studio-Pro. That said, there are major differences from a Model B and this Belt-Idler-Drive unit although viewed from the top, front and sides it looks like a Model B without the "B" on the front badge shifter-plate. Same basic platter and platter well, switch and light are placed as a model B, same basic motor (Bodine) although this type unit carries a "designator" letter and numeral after the model on the motor which is usually engraved NYC-12, this series carries NYC-12A1. The A1 is Bodine's way of saying this is a special purpose unit for this type use. Approximately 600 were hand-built in Russ Friend's garage workshop; today, they are very scarce.
Once the platter is off, the differences in this unit vs the Studio-Pro Model B become obvious. When you check the idler wheel you will find the thickness of the center/bearing area of the wheel has changed considerably from a Model B which measures approximately 17.70 mm. The B.I.D. measures approximately 11.70mm, a BIG difference in overall thickness of the bearing shaft area. The stock B.I.D wheel was precession lathe-turned in Russco's workshop, cut down to the necessary thickness for which it was designed. Everything else about the idler is the same as the stock wheels on most of Russco's units and many other brands.
Here is where the B.I.D. gets really interesting, if you are a collector or trying to research the heritage of idler drive units. After removing the 6+ pound cast/lathe-turned platter and looking down into the unit from the front where the shift arm is located, the first thing you notice, the "cut-outs" for parts are markedly different. Then you realize where the Model B motor should be it isn't! There now is a "flywheel"-pulley protruding upwards with a seemingly large diameter two-step capstan in the center. The Aluminum pulley/flywheel measures approximately 101.42mm (4") wide x 7.94mm (5/16") thick with a groove/slot cut along the horizontal axis approximately 3.51mm (9/64") wide. Within this groove runs a belt (best described as a large O-ring) 3.07mm (1/8") thick. This belt travels from around the groove toward the left side of the table to its counterpart aluminum pulley approximately 37.95mm (1 1/2") across residing on the top of the Bodine motor; the belt wrapping around a corresponding groove cut into the pulley.
Side note: The same belt was used on the RARE Russco Mark V. Vari-Speed.
The Bodine NYC-12A1 motor is mounted in the vertical position (as most tables are) from a 3 point suspended Aluminum motor hanger plate held in place by 3 plateform vibration mounts. As seen by other Russco mounts that were chosen as in the Cue-master or Studio-Pro Model B., two of the load bearing mounts (furthermost away from the flywheel/pulley on the capstan) are 106PDL-1A (1/2 pound mounts) and the third member plateform mount closer to the capstan is a 106PDL-2 (2 pound mount). The two (2) pound mount catches the most start-up torque and is 105.98mm (4 11/64") from center-shaft on the capstan/flywheel whereas the two "lighter" mounts are close together, 98.54mm apart (3 7/8") and are located 4 15/16" and 7 1/2" respectively from center of mount to center of capstan.
The flywheel/pulley has it's own independent vibration mounts ( 3, mushroom type) and it's own aluminum hanger plate, height adjustment screw in base and independent oil fill pipe and cap, likewise the Bodine motor, platter well.
Will be adding more in-depth verbiage shortly as measurements proceed and I get this unit back up to specs and spinning. (Click on JPEG's below to start slide show)
CHECK OUT THE PHOTO ALBUMS BELOW! WE'VE ADDED A NEW SET OF PICS OF A VERY EARLY MODEL 12 BID, COURTESY OF RICHARD & VIRGINIA.