Notes from Bill McBride's Visit

Owned by Gary Foster
Sept 08, 2022
2 min read

Ground Floor

Vibration isolation is critical. Look for and report anything that bridges across the Enclosure to Coude or TMA.

Mezzanine Level

Coude Cable wraps have 2 cables in one slot.

Cables can get dirty and bind. Cables in the cable wrap should be cleaned on Preventive Maintenance (PM).

Bill changed mount cable wrap. Coude wrap should be changed to match.

Delta chain between tower and cable wrap for tension relief. Probly ahould do a PM to test delta chain operation.

Cable wrap auto-greaser near the ladder. Needs PM to check grease operation.

Coude Azimuth Encoders

There are 4 Heidenhain linear encoders to report Coude position. We can implement logic in the controller to to compare opposite sides to calculate runout.

Encoder tape should be cleaned on PM. Remove all covers. Find the procedure.

There's an installation fixture and procedure. Heidenhain will loan rollers for tape installation.

Qty 4 3 axis Accelerometers are installed on coude. Connect to a DAC in rack 6. NI system is networked to a switch. There's another one on the mount. Need the subnet connection info.

Lightning detector near mezzanine door. Battery is dead.

Crane at clean room door is connected to coude and enclosure. transmits vibration. Needs to be fixed.

Utility level
Cable wrap
Dust causes cables to bind.
Cables need to be cleaned on PM. Cables need cleaning.

Delta chain has excess slack. Needs to be fixed. See photo.

Air knife is vibration concern

Enclosure cable wrap rollers can rust and sieze. Causes dragging and vibration. Can detect by seeing scratches on the wrap bed.
Need to inspect cable wrap rollers on PM.
Need to inspect truck rollers on PM.

Cables and slots need to be cleaned on PM.

There's a Heidenhain alignment fixture and unit somewhere.

There's a procedure to align mount motor gear to the drive wheel somewhere. Also must adjust commutation of the drive.

Telescope level
Cooler cabinet hard bolted to deck without vibration isolation.

Mount has multi position locking pins. 2 pin positions, check for balance before removing pin.

Shutter crawlers should be greased on PM.

Enclosure azimuth lightning brushes resistance should be checked on PM.