11/17-11/18/08

College of Optical SciencesThe University of Arizona

1

APOMA Fall 2008 Workshop

Stages and rotary tables

11/17-11/18/08

College of Optical SciencesThe University of Arizona

2

APOMA Fall 2008 Workshop

Linear stages

• Examine various types• Note key components• Measure pitch and yaw with PSM• How to avoid damage to stages• How to fix if damaged

11/17-11/18/08

College of Optical SciencesThe University of Arizona

3

APOMA Fall 2008 Workshop

Types of linear stages

• Recirculating ball on ground rod• Dovetail slide• Ball in V groove or pair of cylinders• Sliding wedge• Scissor jack• Flexure

11/17-11/18/08

College of Optical SciencesThe University of Arizona

4

APOMA Fall 2008 Workshop

Types of nuts or actuators

• Recirculating ball• Pre-loaded nuts and thrust bearings• Micrometer and spring• Fine pitched screw, brass nut and grease• Plain nut of plastic material• Servo or picometer

11/17-11/18/08

College of Optical SciencesThe University of Arizona

5

APOMA Fall 2008 Workshop

Tilt stages

• Gimbel type pivots• Corner pivot• 2 or 3 degree of freedom• Goniometer stage – virtual pivot• Preload – spring or magnet

11/17-11/18/08

College of Optical SciencesThe University of Arizona

6

APOMA Fall 2008 Workshop

Rotary stages

• Air bearing (or oil hydrostatic)– Rotary linear motor plus encoder disk

• Ball or crossed roller• Solid mechanical and grease

– Worm gear driven– Encoder is the worm drive

11/17-11/18/08

College of Optical SciencesThe University of Arizona

7

APOMA Fall 2008 Workshop

Avoid damaging stages

• Shock like dropping, removing actuator• Screws that are too long when mounting• Jamming into stop at end of travel• Trying to move when stage is locked• Loads & moments that are too large• Contamination, rust & no lubrication• Leaving springs in stretched position

11/17-11/18/08

College of Optical SciencesThe University of Arizona

8

APOMA Fall 2008 Workshop

Fixing stages

• Loosen gibs – screws along way• Retighten to get uniform feel over travel• Keep ways and screws clean• Lubricate ways and screws• Use spanner to rotate micrometers• Don’t loosen too much & loose balls

11/17-11/18/08

College of Optical SciencesThe University of Arizona

9

APOMA Fall 2008 Workshop

For the lab• Stages are labeled • Identify and note details of main components• Move stages and feel stiffness of adjuster• Note backlash or lost motion on each• Note how gibs are adjusted• Note center or rotation for tilt stages• Figure out scale reading on large rotary table• Note how hexipod works