Tomelleri S.r.l. ® Copyright 2007 © ASTRONOMY AND RESEARCH July 23rd 2008 VST Meeting1

VST Project Primary Mirror Support System Progress Meeting Villafranca, July 23rd, July 23rd 2008 VST Meeting

The supply of the M1 Support System includes: Axial force actuators Axial fixed point actuators Astatic levers Lateral fixed points Absolute M1 Measuring System Safety devices Harness Prototypes of all devices Performance tests Subsystems integration on the M1 cell M1 Support System testing Integration of Auxiliary Units Documentation July 23rd 2008 VST Meeting3

The Executive Design of the Axial Force Actuators, the Axial Fixed Points, the Astatic Levers and the Lateral Fixed Points, has been delivered after approval, while the final design of Safety Devices will be carried out after the completion of the analysis for earthquake. The related Harness has been defined for the most part, and cables have been purchased. The first lot of 42 actuators has been assembled and tested with performances within requirement. One prototype of the Axial Fixed Points, of the Astatic Levers and of the Lateral Fixed Points, has been tested, modified where necessary. They all passed the tests on the related test bench and are now ready to be produced. The Mirror Cell, the Dummy and the Rotation System are in our facilities. The crane to perform the integration will be delivered to us within the first days of August. July 23rd 2008 VST Meeting4 PROGRESS SUMMARY

AXIAL FORCE ACTUATOR July 23rd 2008 VST Meeting5 The first 42 Axial Force Actuators have been tested and they all satisfy the requirements and particularly: - Maximum force range up 400 N can be obtained also when the sphere starts at a distance 1.6 mm from the mirror pad - Accuracy is better than 0.3 N with step 1 N. - Passive stroke is at least 3.2 mm when the actuator supplies 400 N, and the force is in any case less than 1500 N - Maximum force rate more than 20N/sec - Axial stiffness 200 N/mm - Maximum current < 0.1 A (nominal value 0.95A) Each actuator is certificated every 0.5 mm with the proper force- displacement diagram

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7 Load-displacement diagram (e.g.)

July 23rd 2008 VST Meeting8 Performance Test diagram (e.g.)

July 23rd 2008 VST Meeting9 42 Axial Force Actuators assembled and tested

July 23rd 2008 VST Meeting10 Items to assemble the next 42 Axial Force Actuators

In June one prototype of the Axial Fixed Point has been assembled and tested on the appropriate test bench. Some changes have been brought because the stiffness has been measured to be less than the required value 9000 N/mm (Ref. NCR-VST-TOM- 009) and they are: a)Only one piece between the springs and the load cell b)Massive sphere c)Steel pieces instead aluminium - Measured stiffness is now N/mm - Passive stroke 3.2 mm with maximum load less than 1500 N - Preload between 580 N and 700 N Accuracy has not been measured because the related software is not yet available but it has been verified that the two LVDTs measure the axial position with the required accuracy. July 23rd 2008 VST Meeting11 AXIAL FIXED POINT

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Axial Fixed Point on the Test Bench 14July 23rd 2008 VST Meeting

In June one prototype of the Astatic Levers has been assembled and tested on the appropriate test bench. Some changes have been done because it was found that the accessibility for calibration was difficult (Ref. NCR-VST-TOM- 008). Therefore the following changes have been done: a)Adjusting and locking the left-right screw by means of axial screws and special tools b)Locking of the counterweight by means of fork key Accessibility is now guaranteed. Performance achieved: - Accuracy better than + 5 N - Force adjusting range over 50 N 15 ASTATIC LEVER July 23rd 2008 VST Meeting

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July 23rd 2008 VST Meeting17 The previous solution The new solution

July 23rd 2008 VST Meeting18 Astatic Lever on the Test Bench

July 23rd 2008 VST Meeting19 Dummy to test accessibility

In June one prototype of the Lateral Fixed Points has been assembled and tested on the appropriate test bench. No change was required apart from the foreseen adjusting of the preload of the joint. Performance achieved: - Preload between from 600 up 800 N in both directions - Stiffness N/mm (requirement > N/mm) - Passive stroke 5 mm in all directions - Maximum force on the mirror is 1300 N 20 LATERAL FIXED POINT July 23rd 2008 VST Meeting

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July 23rd 2008 VST Meeting22 Lateral Fixed Point on the Test Bench

Load-displacement diagram 23 July 23rd 2008 VST Meeting

Before proceeding with the final design of the Safety Devices we are waiting for the verification results by BCV and the decisions by INAF. If necessary, it is possible to add 2 safety devices at the East and West positions, working axially on the top side and on the bottom side as well as on the lateral sides with two pads. Such devices can be brought back c.ca 100mm so to avoid any interference with the mirror handling. The two extra devices are foreseen to be moved from an accessible location; from this same position it is possible to adjust the backlash with the mirror when desired. 24 SAFETY DEVICES July 23rd 2008 VST Meeting

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The preliminary diagrams of the harness have been completed and in July cables and connectors, fulfilling the standard ESO, have been purchased, while the distribution boxes and repeaters have been delivered to us. Now with the mirror cell in our facilities the accomodation of the cables can be defined and carried out, and particularly cabling support shall be defined. 26 HARNESS July 23rd 2008 VST Meeting

The system integration and test activities of M1 cell will be performed at our facilities in a dedicated area. A crane, 3 tons capacity and 4 m radial stroke, equipped with non standard gearboxes to have a velocity of 1 m/min, will be installed. The handling of dummy is foreseen to be done by three adjustable tie rods and moved by a Hydra-set. The accuracy of mirror cell and of the dummy will be verified by two different articulated arm measuring machines ( Spazio 5000 and Metris 3000 ), both certificated. Particularly it will be verified if the position of the threaded bores is accurate enough to allow measurements related to the direction of the astatic levers in relation to the mirror. From the first rough measurements the dummy has the some dimensions as the real mirror and the dimensions of mirror cell is accurate enough. July 23rd 2008 VST Meeting27 INTEGRATION AREA

Integration Lay-Out June 5th 2008 VST Meeting28

Fondation ready to accept the crane July 23rd 2008 VST Meeting29

Mirror cell on supports during the first verifications verified July 23rd 2008 VST Meeting30

Dummy on three supports ready for verification July 23rd 2008 VST Meeting31

July 23rd 2008 VST Meeting32 Handling for dummy

Support and Rotation System July 23rd 2008 VST Meeting33

Gear and Shafts for the Rotation System July 23rd 2008 VST Meeting34

All procedures for mounting, adjusting, maintenance of all subsystems after the integration in the Support System are under definition, as well as the test procedures of the whole Support System. At the moment the complete procedure for the integration and calibration of all subsystems has been prepared, and together with the procedures to mount and dismount the dummy in the mirror cell are ready to be submitted to INAF. A complete list of these procedures is available. It is also foreseen to perform accessibility tests to all operations, as for adjusting and maintenance the M1 Support System in real conditions, by simulating the effective encumbrances. At the moment it has been decided to adopt special tools to allow access to eight astatic levers during mounting and calibration. 35 INTEGRATION PROCEDURES July 23rd 2008 VST Meeting

Procedures list 36 Axial force actuator assembling Axial Fixed Point assembling Astatic Lever assembling Lateral Fixed Point assembling Safety Devices assembling Verification of the mirror cell and dummy Dummy assembling Integration of the Axial Actuators Integration of the Astatic Levers Integration of the Lateral Fixed Points Intagration of the Safety Devices Integration of the Absolute Transducers Mounting and dismounting of Dummy Integration of Harness Verification and calibration of the Astatic Levers Verification and adjusting of the Safety Devices. July 23rd 2008 VST Meeting