Last updated: 12-19-01

Project: DEIMOS
Stage: Grating Slide
ID #: KDGS-001A
Engineer: J. Osborne

Mechanical Description of Stage:

Delivers one of four items: 3 gratings and one mirror.  Has a 200 pound counterweight moving on it's own linear stage.

Electronic Description of Stage:

Two fiducial schemes: Main (Bit 4) and Primary Reference Mark (PRM) (Bit 38).
Find the main fiducial edge, set position = 0. Drive to slider, find PRM and back off (X distance) to clamp position.

Required setting accuracy:

TBD but we assume about 0.006"

Performance requirements and design goals
Component Requirements 1
Motors: Galil #50-1000  
Gearbox: Two stages of chain/sprockets plus spur gear set then ball screw.  Counter weight slide:  Main stage has 1 stage of timing belt/sprocket then ball screw.  
Limits 2: Microswitch BZ-2RW822-A2 "primary" and DT-2RV22-A2 "secondary"  
Fiducials: TRW #OPB-970-T55 (Optical)  
Encoders: BEI #MX213-25-1000 (4000 quadrature counts/rev)  
Air Cylinders:-  
Air Solenoids:-  
Lock/Clamp/Brake:- Yes
   See KDGS-002A 
Interlocks: See interlock schedule  
  1. Speed, temperature, accuracies, electrical power, pressurized air, lubricant, coolant, N2 purge, ...
  2. Primary (inner) and secondary (outer) limits. These can be magnetic, optical, or physical contact

Manufacturer's specifications and limitations
Component Maximum Operating Condition  Safe Ops Condition  Requirements 
Motors: Galil 50-1000 3750 RPM, 205 oz-in peak torque    
Air Cylinders:      
Air Solenoids:      

Final Mechanical Assembly and Testing Results

Tests performed by:

Motor tuning parameters under different spacial orientations and environment
Parameter    Set
PID Filter: KD:
154 (old)   200 (new)
  29 (old)     20 (new)
  27 (old)       2 (new)
Acceleration (pulses/sec^2):  
Deceleration (pulses/sec^2):  
Speed (pulses/sec):  
 75000 cps Maximum
Other: CN 1,1 
CB 4 (home) or CB 38 (PRM) fiducials

Motion Parameters

Linear Stage (constrained)
Distance from "home" 1 Position Motor Counts  Physical Units Time to Reach
Software Limits:  Forward
Primary (inner) Limits:  Forward
Secondary (outer) Limits:  Forward
Position # (@ 270 Degree Position Angle) 2 (Mirror)
-9,323,055 (Go To)
     +28,652 (Offset)
-4,218,400  (Go To)
     +57,586 (Offset)
+126,012    (Go To)
  +51000    (Offset)
  1. "Coarse" if from optical interupter, "Fine" if from an encoder index pulse. Home is defined as zero counts.
  2. Primary limits signal the controller to stop motion. Secondary limits cut motor power and require intervention to move out of them.

Resolution of Stage
Encoder Counts/Inch Counts/Millimeter Counts/Degree
On Motor    
On Stage


Mechanical Drawing(s) # D0920, D4100 and D4189

Electronic Drawing(s) #EL-3066

Sign conventions are such that a positive motion of the motor turns the motor in a CW direction as viewed from the drive shaft looking back into the motor, and will drive the stage towards the forward limit.

The Grating Slider stage uses Controller # 2, amplifier 2A and is connected to the D axis.