Swing Arm Mechanics

• wiki: Swing arm mechanics overview
• wiki: Swing arm beams
• wiki: Swing arm axis
• wiki: Swing arm mounts
• wiki: Swing arm T-gusset
• wiki: Swing arm Habour - drawings missing (TODO), SX harbor top has to be changed.
  
• wiki: Swing arm LBT-interface
• wiki: Swing arm test stand
• wiki: Swing arm MPIA installation
• wiki: Swing arm verification
• wiki: Swing arm LBT installation
• wiki: Swing arm installation calibration
• wiki: Swing arm incident

End Stop position monitoring:

Side	Date	PP	WP	Ambient T	Remarks
DX		18884	5872		after first calibration unit alignment
DX	2014-11-30	18884	5862		overwrote the park position -> not parked
DX	2015-02-xx	--	5872
DX	2015-12-11	18870	5854	3.8C	Park position switch was replaced with mechanical one in between
SX	2015-12-11		18662
SX	2016-02-24		18662	2.21C
DX	2016-02-24		5854	2.21C
SX	2016-05-15		18661	8.00C
DX	2016-05-15		5854	8.00C
SX	2017-04-28		18663	1.8C	The working pos switches have been changed to mechanical
DX	2017-04-28		5854	1.8C	The working pos switches have been changed to mechanical
DX	2017-12-02		5854	3.5C
SX	2017-12-02		18664	3.5C

Issue Tracking

• 2016-02-24 SX Working Position Switch: The working position switch was not changing to set after reaching working position.
  • 2016-03-08 Investigation on the switch showed that it was not initialized properly. This is a known issue with the electronic switches. When after a power cycle the 24V is not applied fully but to low for some time the switch does not initialize and remain in a fail state (fast blinking LED). Investigation: The switch was tested manually (climbing up) and monitored on the web interface. No reaction seen. Opening the switch the LED was found blinking. Resolution: The 24V line was detached and attached again. The switch was properly initialized and working again.

2016-10-16 DX CalUnit vignetting: The DX CalUnit showed strong vignetting in the yellow pupil of the WFS. Re-alignment of the DX Cal-Unit was considered as solution. The DX Calunit tilt was rotated toward park position of ~3 mm. This relaxed the positioning of the secondary but did not remove the vignetting. Further investigation lead to the conclusion that one fiber was loose. Investigation: Taking picture into the CalUnit on horizon. The picture show different illumination of the holograms. Resolution: Fixing loose fiber on the back of the CalUnit.

Left side: In the yellow circle, the not fully illuminated hologrom due to the loose and tilted fiber. Right side: The same with the fiber fixed

Swing Arm Electronics

• wiki: Swing arm motor controller
• wiki: Swing arm white light source
• wiki: Swing arm green laser source
• wiki: Swing arm interlock

Known Issues:

• Setup router.
• Change the power lamp on front panel.

Malfunctions:

• Green laser source had connection errors. Low temperature problem of the LED board?
• White light source didn't connect and work. Low temperature problem?

Calibration Unit Mechanics

• wiki: Swing arm holder
• wiki: Swing arm lense tube
• wiki: Swing arm fiber plate
• Alignment

Open issues:

• Test of fiber plate with bigger holes (0.2mm). Pre-aligned test plate is already at LBT.

Calibration Unit Optics

• wiki: cal unit optics design
• wiki: cal unit aspheres
• wiki: cal unit lenses
• wiki: cal unit hologram
• wiki: cal unit fibers
• wiki: cal unit 227 new
• wiki: cal unit 227 old

Tenon

• wiki: Tenon mechanics

Calibration Unit Verification

Verification Matrix

Calibration Unit Alignment

Side	Date	X	Y	Z	RX	RY	Comment
DX	2015-02-21	-2.52	-3.77	4.35	-471	56
DX	2015-04-28	-2.77	-8.90	-2.00	51.0	103.0	after crash
DX	2015-04-29	-2.59	-8.84	-1.96	46.9	109.6	day
DX	2015-04-30	-2.94	-8.18	-2.08	-150	12	day
DX	2015-05-01	-2.94	-8.18	2.08	-44	62	day
DX	2015-05-01	-1.00	-6.50	-2.10	-310	215	night
Side	Date	X	Y	Z	RX	RY	Comment
SX	2015-12-10	4.87	-0.03	7.80	215	-57	Focus to be adjusted later in the run (Done 20151213)