Filter Wheels

Drawing: RCT001/6
EOS Drawing:SCH-4025-1
Sketches: MM 10-3
Motor:  d.c. servo with 25:1 reduction
Motor Encoder: 
From Adrian's notes I see
Scale:  1183.033 for FW1 
Scale:  1182.261 for FW2
Rotation: Positive is left as viewed through access port. 
Overall Encoder: 1000 lines per rev. giving 1 arcminute
Limits: none although SCH 4028-1:3 shows limits
FW1 Controller: PMAC#12
FW2 Controller: PMAC#13
FW1 Drive Amplifier:Amp 9  
FW2 Drive Amplifer: Amp 10 
Homing: one per wheel connected to the HomeFlag 
The schematic show "detents", these notches are closed when the filter is
    in position.  They are connected to the +LIM.
Notes: FW1 
Positions per wheel: 9 (1,2,3,4,5,6,7,8,9)
There are nominal positions tabulated for each filter slot
Max Speed: 10 degrees per second  5 deg/sec/sec acc.

Filter Size:  4.5 inch
Thickness: 2-10 mm

Revised Oct 30, 2006 following error in filter wheel assignments.

The software should disable the wheels when not rotating them.

The numbering is 1-9 since the wheels are stamped with numbers and I want to be consistent with this.

The home flag is at about filter position 8.25.

Warning:There is a confusion whether as to the "Upper" and "Lower" filter wheel. I will follow EOS notation that the "Upper" filter wheel is actually the upper when taken out of the telescope. In the telescope it is the wheel closer the floor. It is FW1.

The "Lower" filter wheel is FW2 and on the telescope is farther from the floor. Because of this confusion, I will try not to use the terms Upper and Lower, but instead say FW1 and FW2.

Single Number Scheme

• EOS configuration file

Software

Photos