This phonograph is a heavy, well built machine that plays 33,45 and 78 rpm records. Speed changes are accomplished by three different brass capstans driven by a common belt and rotated by the speed control against the idler. I have installed new batteries, replaced original slipping belts with small diameter O rings to eliminate slippage and the platten turns easily and smoothly. It uses an idler wheel to drive the platten. Is the motor speed adjustable? Has the idler diameter shrunk from wear? Anyone tackled this one successfully?