1. TEST MODULE WG Cradles for CLIC module supporting system
H. MAINAUD DURAND, N. CHRITIN

2. SUMMARY Introduction: different types of cradles Requirements
Boostec cradles
Epucret cradles
Conclusion: next steps concerning cradles

3. Introduction: girders and MB quad support
Several components will be pre-aligned on supports:
 Along the MB:  Along the DB:
RF structures on girders  PETS + DB quad on girders
MB quad on interface plate
DB and MB girders will be interlinked with their extremities, based on so-called cradle. This allows a movement in the transverse girder interlink plane within 3 degrees of freedom (“articulation point between girders”). (Longitudinal direction adjusted thanks to a mechanical guiding).
MB quad is mounted on an interface plate, allowing an adjustment along 5 degrees of freedom (longitudinal position will be positioned manually).

4. Introduction: test module and cradles
Epucret S M
Boostec S M
Boostec S M
Epucret S M
S/M ? M S
M C M S
M C M M
Master side
Installed
Ordered S
Slave side
To be designed 4

5. Introduction: terminology
Girder
Ves
Targets for fiducialisation
Cradle
Linear actuators
Sensors
Longitudinal adjustment
Mechanical pre-alignment 5

6. Requirements : main data
Adjacent girders will be interlinked with their extremities (so called cradle), allowing a movement in the transverse girder interlink plane within 3 degrees of freedom (X, Y, roll)
Colinearity of mean axis of Ves on two adjacent girders: 5 um, along X and Y axes in the transverse girder interlink plane 6

7. Requirements : main data
Longitudinal positioning of +/- 0.3 mm will have no impact on the articulation point
Each extremity of a girder equipped with a cradle
On each cradle: several interfaces, positioned within 0.1 mm, and measured within 5 μm w.r.t mean axis of Ves.
Once one girder is installed, the second shall be installed from the top, with no interferences with supports and stretched wires already in place
Area protected : stretched wires
Interchangeability between cradles. 7

8. Requirements : interfaces
With sensors:
Each cradle hosts the following sensors:
1 cWPS, screwed on a 3 balls interface
1 oWPS, screwed on a 3 balls interface
1 inclinometer, screwed on a 3 balls interface
1 temperature probe, inserted in a hole with a diameter of 4.1 mm
Cradles must be rigid and stable in time, with no difference in their shape when equipped or not with sensors (deformations < 2 μm)
Slave and Master cradles equipped for test module. Once everything is validated, only master cradles will be equipped. 8

9. Requirements : interfaces
With girders:
Reference surfaces for Boostec: one side / one below
Reference surfaces for Epucret: one above / one side
Boostec
Epucret 9

10. Requirements : interfaces
With actuators:
Each cradle supported by 2 vertical linear actuators, already ordered, and on radial linear actuator.
Range of each linear actuator: +/- 3 mm, resolution < 1 μm
With mechanical pre-alignment:
Manual adjustment in longitudinal: +/- 0.4 mm, resolution 10 μm
With articulation point:
Constraints and external forces applied:
Vacuum
Waveguides 10

11. Boostec cradles
Design of the articulation point 11

12. Boostec cradles
Design of the Boostec cradle: 12

13. Boostec / Epucret cradles13

14. Epucret cradles 14

15. CONCLUSION
First cradles installed are being tested in 169. Results are promising.
Tests under progress
Qualification of concept of articulation point (Micro-contrôle versus Boostec/CERN:
Metrological evaluation
Behavior of the articulation point w.r.t micrometric displacements, w.r.t larger displacements (+/- 1 mm)
Impact at beam level
Impact of displacements on adjacent articulation points
Validation of algorithm of repositioning
Implementation of active pre-alignment 15

16. CONCLUSION
Rigidity and stress measurements on 3 pieces foreseen this summer, to validate the theoretical study
Epucret cradles received (under CMM measurements), other mechanical parts (mechanical pre-alignment, articulation points) ordered last week, to be delivered end of July 2011.
Technical note will be ready end of July. 16

17. Spare slides

18. For a force applied of 10 N (micrometric screw) at the level of the hole (blue area), we have a displacement of 7.5 mm. At the output, we have a displacement of 0.3 mm.

19. Elongation of 0.053 mm under a load of 400 kg
Constraints in “ailettes” under load, with a displacement of 2 mm

20. Pivot under load and inclined (one vertical actuator at 3 mm, the other one at – 3 mm)