Differential Screw Spindle Position Adjustment
Background
Parallel spindles are essential in the coating process to ensure even coating and to prevent telescoping of the roll
Problem
Even a few thousands of an inch off of a parallel axis will cause telescoping to occur over hundreds of roll layers. Installation is incredibly difficult as movement of this spindle before it is locked down resets any progress made
Differential Screw Solution
After research I found that a differential screw could allow us to have the spindle locked while we adjusted its position. A differential screw utilized 2 different pitches on the bolt, which can result in micrometers of adjustment.
My design followed a similar setup to the image above. The bottom block was locked in placed, and the movable block was connected to the spindle. The video below shows the SOLIDWORKS model in motion to demonstrate how it worked
Differential Screw Result
Images of the setup in position cannot be shown do to the proprietary nature of the work where they were installed
This system proved effective, though required many iterations to effectively work. Initially, I manually machined the bolt (above). This proved to be a mistake, as I could not ensure my die usage was parallel for the threads. I designed the G-Code and made a CNC version of the setup. This was implemented to success, and we ensured parallel spindles before removing this installation device.