dusty wrote
The online calculator that you reference works well; provides accurate results within the limits that are imposed. To calculate shaft speeds in the Mark requires far more accuracy that can be achieved with with this calculator.
The one that I reference earlier in this thread requires at a minimum 5 decimal places to get good results.
To clarify, I did not use the calculator for speed calculations. I used it to confirm a hypothesis: In a case with a larger and smaller diameter pulleys, neither contact areas is half of the circumference. The larger pulley has a contact area exceeding 180 degrees. The smaller pulley has a contact area less than 180 degrees. In linear terms, for the question you asked, the large pulley contact exceeds half of the circumference while the small pulley contact is less than half of the circumference. And, finally, the two do not cancel. Therefore the total contact area does not remain constant. (The only part that is hypothetical is that the two do not cancel, my plane geometry is rusty and not well maintained. ;) )
dusty wrote
So the stop prevents the Control Sheave from pressing hard against the arm of the porkchop. Stops it dead upon contact with the stop screw. Really has nothing to do with speed adjustment except to stop it (going too far).
It's the arms on the Control Bracket (89) where they form the stationary hinge point that the porkchop swings on. And nothing to do with pressure, prevents the 'back side' of the spinning sheave from ANY CONTACT with the stationary bracket. Correct, nothing to do with speed adjustment except to stop/limit it. And of course, those of us that set the indicator dial according to the high speed adjustment procedure set indicated FAST and the stop both equal to the speed that correlates with the belt position we chose.
- David
