M6025 CGH Positioner Customization
Model M6025-6DL
Choosing a Configuration
The configurations differ in the location of balls (red) and their preload springs and in the location and number of adjustment knobs (green).
There are 3 binary choices, yielding 8 configurations. Each configuration is designated by a 3-character model number suffix. For example, "M6025-6DL".
- Choose (5) or (6) axes. A 6-axis positioner requires you to turn 2 screws an equal amount to achieve decenter without rotation. Clock rotation is unlikely to remain fixed if you frequently adjust decenter. A 5-axis positioner has 2 of the 3 balls controlled by a single screw and ramped shaft so that decenter occurs without rotation. For this reason, we regard the 5-axis positioner as best for most applications.
- Choose direct (D) or indirect (I) drive for the lone ball. The direct drive is more kinematic. The indirect drive configurations, which use a ramped shaft to move the ball(s), are more compact because of where the adjustment knob is located.
- Choose handedness (L) or (R). The letter L resembles the L-configuration shape when oriented as shown with 2 balls (red) at the bottom and the tilt-tip-focus knobs (green circles) on the front face. Configurations L and R are mirror images of one another.
Preferred Orientations
The M6025 positioner is comprised of a stationary base (light gray) and a moveable J-arm (darker gray). Three screws (green circles) control tilt, tip and focus. To adjust only focus, you must turn all 3 screws by the same amount. For a vertical interferometer axis, the 3 screw knobs are best located below the positioner so that the moveable weight is resting on the screws instead of hanging from the preload springs.
All models have 3 balls (red) that constrain centration and clock. For a horizontal interferometer axis, the best orientation is as shown with 2 balls below the arm. If you need the optic axis to be lower, then an orientation 180° different, with 2 balls above the J-arm, is acceptable. Less acceptable is 1 ball below the J-arm. You should especially avoid orientations with 1 ball above the J-arm.
