IMACS progress report no. 23 B. Bigelow 29 February 2000 1) Project Status Currently scheduled tasks: Status: a) Filter server fabrication early start b) Long camera mech. design (Bond) re-scheduled c) Shutter fabrication (Storts) late start d) CF guider mech. design (Hare) late start e) Mask server fab. (Kowal) late start f) Collimator mech. design (Bigelow) late g) Dewar fab. (Luppino) on schedule h) Science array controller fab (Burley) late i) Motion control electr. fab (Carr/Berger) on schedule j) Control software design (Birk) on schedule Details: b) Mech design of the long camera will be rescheduled in March. c) Late availability of machinist delayed start. e) Mask server fab delayed by early start of FSS fab. f) Late finish of Coll. prelim design is delaying design start. h) Controller design is running 2+ months late Other project progress: Robert Storts officially joined the project in the first week of February. A new PC was purchased for Robert to run the MasterCam CAD/CAM package, and he converted the tooling and readouts on his NC mill to metric units as required for IMACS. Some fab time will be lost in March as Robert attends Mastercam training. George Berger, our consulting electronics tech, finished the prototype motion control chassis' (power supply and stepper chassis') in February. The complete control system for the filter server will be tested in March. Mechanical design of the long camera opto-mechanics has been delayed until the collimator prototype cell has been demonstrated. Tim Bond has started design of the disperser server, which is probably the most complicated and challenging mechanism in the instrument. The project schedule will be revised in March to reflect the changes. 2) Optics (Sutin) Optics: 1) Three more gratings have arrived. We now have one 300 l/mm, one 300 l/mm (6th order), one 600 l/mm (blue), and one 1200 l/mm. We are expecting another 600 l/mm (red) soon. 2) Alignment sensitivities for the entire spectrograph were computed. The numbers were, as expected, not very large; ie, the alignment tolerances are not very tight for the most part. The numbers were post-massaged by B. Bigelow, who has the results. 3) Flexure sensitivities for the entire spectrograph were computed. These numbers were also post-massaged by B. Bigelow, who has the results. 4) The material for coating test samples was ordered from Ohara. 5) The quote from Coherent for coatings came back at about $250,000. We are therefore looking for alternative coaters. 6) Because the coating house is unknown, the field lens will be shipped to OCIW. Optics TODO List: 1) Coatings, again 2) Baffle analysis 3) TV Camera designs 4) Filters 5) Asphere fabrication 3) Electronics (Carr) Controls for the filter server are nearly complete. Testing should start in the first part of March. The motion control computer has been assembled and is working. The first version of Greg Bredthauer's control software had a minor bug that has been fixed. The program now appears to be work as expected. George Berger completed the two motion control prototype chassis. Currently complete electronics hardware: - motion controller PC - motion control power supply chassis (prototype) - motion control stepper indexer chassis (prototype) Computer control of the filter server motion stage, using the above electronics should occur in the first half of March. 4) Software (Birk) Dave and I setup the motion-controller computer. After installing and debugging the communication software (by Greg Bredthauer) Dave installed one motor controller board. Although we are not driving motors yet, I can send out pulses to an oscilloscope. This allows me to test acceleration/deceleration ramps, setting of speed, pulse train length, etc. For March: Drive stepper motor for filter changer prototype. 5) Mechanics Tim: February saw the completion of all of the drafting required for the filter server mechanism. This included finalizing the IMACS drawing numbering and revision control system. All of the filter drawings were modified to the new system, and the drawings are now available on the server. The parts for the filter server are progressing through the shop. After the filter server work was completed, I began working on the disperser server system. For March: Design of the disperser server grating cells and cell support/tilt mechanisms. Tyson: Camera Shutters: 1. The camera shutter design is complete. Assembly drawings are needed to complete the drawing package - Mary is working on them. 2. A meeting was held in February to discuss motion control and motor electronics issues with electronics engineering. A request was made to consider adding proximity switches to the design to aid in motion control. 3. The linear motors and associated components, minus the power supplies, have arrived. Fasteners are still on order. 4. Parts manufacturing has begun. Shop time estimates; including programming, setup, and machining, have come in at approximately 100 hours per shutter. 5. Fabrication of the first shutter has started. Guide Cameras: 6. After further consideration, the redesign of the center field guide camera mechanical layout looks promising. Initial designs for a cantilever arm on which the optics would mount and rotate in and out of the field have been examined. Space availability in the front of the instrument is now being investigated. 7. The optical design and layout has been discussed. It is proposed that a configuration similar to the Shack-Hartman camera be used for the center field guide camera as well. For March: 8. Future work on the center field guide camera includes developing solid models for the proposed cantilever mechanism, further analysis of layout and space constraints on the instrument solid model, and continued opto-mechanical design work. Bruce: Error budgets were completed in February for image motion and initial alignment, for the instrument plus long camera, and plus short camera. In general, the alignment allowances are readily achievable, while the image motion allowances will be much more challenging. The budgets are posted on the IMACS website. Preliminary design of the collimator opto-mechanics continued in February. A conceptual design for a flexure-based lens cell was posted on the website, and a "virtual design review" was held. Comments were received from several of our PDR reviewers. The primary suggestion was that we prototype the fabrication, alignment, and assembly of a lens/cell unit. A prototype assembly was then designed and drawings were completed in Feb. RFQ's for fabrication of the parts will go out in early March, as our internal resources are used up at the moment. Material selection for the slit masks has entered the final stages. The two finalists are 304 stainless steel (for thermally insensitive masks) and titanium (for thermally sensitive masks). An order was let for hydroforming tooling, and for 12 prototype masks to establish final thickness of the mask materials. Slit mask server fabrication started in February with the contracting of the mask frames to Rettig Machine in Redlands, Ca. Dewar flexure testing was planned to start in Feb, but has now slipped into March. A pair of 1-micron resolution displacement sensors were purchased to facilitate testing of the CCD array assembly and are now in-house. For March: - Fabrication of the flex cell prototype parts - Schedule revision - Collimator cell / barrel design - Dewar testing Gerry Luppino: No report this month. 6) Detector Systems (Thompson/Burley) Guider cameras -------------- 1 - The guider camera housings were sent for dip brazing, and should be back this week. (They arrived 2/29) 2 - the next thing to do is still to measure the low-speed read noise and to implement MPP mode imaging. Array cameras ------------- 3 - the dsp_timing pcb, the clock_driver pcb, the sig_proc pcb, and the power_utility pcb were completed, and sent for fabrication. 4 - both backplane versions were completed (one 4 slot version for the single chip cameras and the 4k x 4k array, and a 10 slot version for the 8k x 8k array), and will be sent for fabrication this week. 5 - some details about the shutter were sorted out. The CCD controller will provide an RS-232 level signal to open/close the shutter (and will time the exposures) and the shutter controller will send an RS-232 level status/error signal back to the CCD controller. The shutter motion profile will be set by the linux box that interfaces with the ccd controller, using its serial port to talk to the shutter motion-controller. 6 - the next thing to do is start the design of the internal header boards, and begin ordering parts to populate the circuit boards. 7) Meeting notes: Next IMACS meeting: 10:15, Weds. 3/29/00, new conf. room. Progress reports included above. Vince to help Robert get up to speed with Mastercam - in progress.