Aux Tel installation notes

Feb 12, 2024, CWS

Looking at options inside Aux Tel dome. AC power is available on rotating dome, but unknown current limit. 

(note there are glitches in this 3d image)

vertical separation between structural tubes is about 3 feet. I need to measure tube diameter and back-side clearance. 
For scale, pupil diameter is 1.2 meters so about the same distance as the vertical spacing between the tubes. 

things to measure tomorrow: 
1) diameter of inner structural tubing: 1 inch OD
2) exact spacings: 36 inches
3) back-side clearances: nearly zero. Largest where clamped to vertical struts
4) size of mount railing on the bottom, for electronics boxes perhaps? 
5) see if intersection of telescope axes is at center of AuxTel dome, or not. I think not, since bottom of hemisphere is at floor level. Measure the vertical distance from dome center to elevation axis. 
distance from mid-plane of hemisphere to elevation axis is 37 inches, plus or minus 1 inch

First mounting ring of tubing is 39 inches above hemisphere plane

Dome radius is 4.57 m 

Note how flatfield screen is rotated relative to dome diameter vector:

possible clamp for inner wall tubing: 

(note from Feb 15 2024- we have clamps in Chile already. )

or:

Use these to mount Thor Labs MB648, 6" x 48" breadboard. 

Conceptual design for mounting to dome interior: 

The ti-tilt stages we plan to use have an adjustment range of +-4 degrees. Since a reflected beam rotates by 2 theta that gives us about +-8 deg adjustment range. 

Wrote a quick computer program to calculate offset angle as a function of elevation angle on dome, to point beams at elevation axis: 

offsetcomputer.m

So if we place the device at 45 deg elevation angle, 1.4 airmasses, we need to rotate the optical bench upwards by 10 degrees. 

That's an elevation of 1 inch additional on a breadboard width of 6 inches. 

Really rough sketch of tilted 90deg mount bracket:

Turnbuckles from McMaster:

Next steps: 

• review conceptual design for mounting
• make full system diagram
• fabricate sloped mount bracket
• order 2 x Thor Labs optical benches
• order turnbuckles and no-shoulder eyebolts with 1/4-20 threads
• 4 outlet 240V PDU for power management for example https://www.gridconnect.com/products/powerpdu-4c-smart-power-distribution-unit?variant=39308263522327#reviews (wait to hear from Fritz Muller about PDUs before ordering anything)

Feb 15 2024: 
Tried out mounting scheme on Aux Tel dome interior. We have appropriate hose clamps and 1/4-20 optical bench component. This is going to work fine I think.