Last updated: 12-17-01

Project: DEIMOS
Stage: Science Filter Wheel
ID #: KDSF-001A
Engineer: V. Wallace

Mechanical Description of Stage:

Seven position: two are "user" positions, so can be selected and exchanged manually.

Electronic Description of Stage:

Standard unconstrained rotary stage with seven positions. This stage uses a standard EL-1236 Stage Interconnect Box, a Galil 50-1000 motor and a single Cherry VN101501 magnetic fiducial. The position can be selected by any one of three means. First, the computer can instruct the wheel to either home the wheel or move to a discrete position. By selecting manual control from the manual paddle connected to Galil controller #1, the filter wheel can be jogged in slow or fast speed, homed, or moved to a discrete position. Finally, the filter can be moved by the push button station that lives on the side of the electronics ring adjacent to the filter access hatch. When moving via the push buttons, the wheel is moved so that the filter slot that is selected is moved to the unload position instead of into the beam.

Required setting accuracy :

Performance requirements and design goals
Component Requirements 1
Motors: Galil #50-1000  
Gearbox:- Bayside 23-50 (Ratio = 50:1) + Drive / spur gear (Ratio = 5:1)   Total Ratio = 250:1
Limits 2: None (unconstrained)  
Fiducials: Cherry VN101501(Magnetic)  
Encoders: Motor encoder: 4000 counts/rev  
Air Cylinders:- None  
Air Solenoids:- None  
Lock/Clamp/Brake:- None  
Interlocks: Yes, 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    
Gearbox:  Bayside 23-50    
Limits:  None    
Fiducials:  Cherry - VN101501 (Magnetic)    
Encoders:  Motor encoder: 4000 counts/rev    
Air Cylinders:  None    
Air Solenoids:  None    
Lock/Clamp/Brake:  None    

Final Mechanical Assembly and Testing Results

Tests performed by:
                                                                                                            C. Harper 3-21-01
Motor tuning parameters under different spacial orientations and environment
Parameter    Set
PID Filter: KD:
Acceleration (pulses/sec^2):  
Deceleration (pulses/sec^2):  
Speed (pulses/sec):  
Other: CN 1, -1     CB 11    
  1. Uphill defined as motor (or driven end of shaft) in lowest position.

Rotary Stage (unconstrained)
Distance from "home"  Position Motor Counts  Physical Units Time to Reach
Position # 1
1 revolution CW
  1,000,000 counts
  1,000,000 counts

Resolution of Stage
Encoder Counts/Inch Counts/Millimeter Counts/Degree
On Motor - -   11.1 counts
On Stage - -   2,778 counts


Mechanical Drawing(s) #D5315

Electronic Drawing(s) #EL-3056, EL-3073

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 Science Filter Wheel stage uses Controller #1, amplifier 1B and is connected to the G axis.