From cjd@roe.ac.uk Fri Jun 1 17:10:14 2001 Date: Wed, 23 May 2001 16:20:01 +0100 From: Colin Dickson To: "'A.Vick@roe.ac.uk'" Subject: Ultracam CDR [ The following text is in the "iso-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Andy, The following comments summarise my view of the mechanical, Ultracam, presentation. 1 General tolerancing requirements need specified, and any requirement generated for a particular telescope. This could be in the form of an error budget, and should make allowance for tolerances, thermal differentials, and flexure. The optics manufacturer ( SPECAC ) requirement specification must be checked for inclusion of operating temperature range etc 2 The Calcium Flouride optics ( approx 108.5 dia. x 15 thick ) need special consideration during instrument build, handling and operation, to protect them from physical damage, stress points ( already identified ), and thermal shock. 3 The truss structural model using LH/RH threaded, 'turnbuckle 'style, trusses should have a 'locking' element beween the truss members, and the spherical nodes of the structure, if they are going to be used to align the mounting plates. The model trusses were not 'locked', and could be rotated easily by hand. The spherical nodes did not have 'flats' around the truss attachment points to allow effective 'locking'. 4 Shimming is proposed for optical alignment, and if adopted for the spherical nodes/mounting plate interface, then the trusses may be simplified. 5 The Dichroic mounts require further investigation, and possibly, optical bench testing to determine an appropriate mount. Cheers, Colin PS I have copied this to Gary Rae. --------------Boundary-00=_L44U6ZW4EFJYM15EUX2Z--