Last updated: 12-19-01
Project: DEIMOS
Stage: Grating Tilt Stage #4
ID #: KDGC-004A
Engineer: J. Osborne
Mechanical Description of Stage:
6" X 8" grating rotator. Tilt angle is maintained even when out of position.
(e.g. no "Home"-ing required.)
Electronic Description of Stage:
Driven by Galil Controller #2 - Axis C - requires
EL-1272 #4 interconnect box.
1. Because of the reverse wiring of the motor,
the command CEC=8 must be included in the software.
2. Stage translation position is +3,228,000
Required setting accuracy:
0.14 arc-seconds
Performance requirements and design goals
| Component |
Requirements 1 |
| Motors:Galil #50-1000 |
|
| Gearbox: None |
|
| Limits 2: Microswitch BZ-RW822-A2 "primary" and DT-2RV22-A7
"secondary" |
|
| Fiducials: TRW #OPB-970-T55 (Optical) |
|
| Encoders: Gurley #8335-11250-CB-S-A, 900,000 counts/rev (Labeled
DEIMOS-2) |
|
| Air Cylinders:- None |
|
| Air Solenoids:- None |
|
| Lock/Clamp/Brake:- Yes |
See KDGS-002A
|
| Interlocks: See lockout schedule |
|
-
Speed, temperature, accuracies, electrical power, pressurized air,
lubricant, coolant, N2 purge, ...
-
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: |
|
|
|
| Gearbox: |
|
|
|
| Limits: |
|
|
|
| Fiducials: Optical |
|
|
|
| Encoders: |
|
|
|
| Air Cylinders: |
|
|
|
| Air Solenoids: |
|
|
|
| Lock/Clamp/Brake: |
|
|
|
Final Mechanical Assembly and Testing Results
Tests performed by: K. Dietsch 8-14-01 & C. Harper 1-3-01
Motor tuning parameters under different spacial
orientations and environment
| Parameter |
|
Set |
| PID Filter: |
KD: |
289
|
| KP: |
74
|
| KI: |
33
|
| Acceleration (pulses/sec^2): |
|
256000
|
| Deceleration (pulses/sec^2): |
|
256000
|
| Speed (pulses/sec): |
|
25,000 counts/sec
|
| Set: CN 1,1 CB 3 CEC=8 |
|
|
Motion Parameters
Rotary Stage (constrained)
| Distance from "home" |
Position |
Motor Counts
|
Gurley Counts
|
Time to Reach |
| Software Limits: |
Forward |
|
|
|
| Reverse |
|
|
|
| Total Rotation |
- |
|
36.9 degrees
|
|
| Primary (inner) Limits: |
Forward |
+258,750
|
+25,074
|
20 seconds @ 5000
|
| Reverse |
-645,361
|
-62,743
|
33 seconds @ 30000
|
| Secondary (outer) Limits: |
Forward |
+279,721
|
+26,997
|
24 seconds @ 5000
|
| Reverse |
-662,020
|
-64,307
|
35 seconds @ 30000 then 5000
|
| Defined Positions |
1 |
|
|
|
| 2 |
|
|
|
| 3 |
|
|
|
| 4 |
|
|
|
| 5 |
|
|
|
| 6 |
|
|
|
| 1 revolution |
CW |
|
|
|
| CCW |
|
|
|
| Gurley Index Position |
|
0
|
0
|
|
-
"Coarse" if from optical interupter, "Fine" if from an encoder index
pulse. Home is defined as zero counts.
-
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 |
- |
- |
11.1
|
| On Gurley |
- |
[1 Gurley count = 10.35 Motor Encoder counts.] |
2,500
|
-
Gear reduction function: Two stages of friction drive plus timing belt
and sprocket: 923.9 X 60/24 = 2309.75
-
Gurley Model #8335-11250-CBSA
-
Backlash:
-
Forward: 233
-
Reverse: -387
-
Repeatability:
-
Fiducial:
-
Encoder:
-
On motor: Zero to 40,000 and back = 0 extra counts.
-
On stage: Gurley lost 3 counts on above test.
-
Air Cylinders:
-
Air Solenoids:
NOTES:
Mechanical Drawing(s) #D4671 and #D0920
Electronic Drawing(s) #EL-3064 and EL-3065
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 Tilt #4 stage uses Controller #2, amplifier 2A and is connected
to the C axis.