Dorkwad, I just re-read your post above, particularly the following passage: "Discovered that the motor housing was no parallel to the chassis because of the 6 springs that attach it to the chassis have to be in just the right spot. There are long ones, short ones, and mid size ones. When they are right, and it takes some experimentation, the speed can be set spot on with absolutely zero drift." My reflex response to this notion is "Huh?" It would seem to me that in the horizontal plane you want the contact patch of the idler wheel to be perfectly tangent to the arc of the platter. In the vertical plane, as you say, the idler wheel should be perpendicular to the driven surface of the platter. This has little to do with the chassis, except that if you attain the goal, there will also be a certain relationship of the drive spindle to the chassis, pari passu.