1. Brussels Gantry Ê Problems with vacuum chambers in plate 4 mostly solved by the workshop in Aachen (thanks) Ë Problem with rotation motor (U-motor) 4 motor replaced and being commissioned now 4 with the help of Marco Giorgi (Peruglia) Ì We made 3 special modules with alignment sensors J.D’Hondt (for Brussels Group) CMS week – December 2004 J.D’Hondt

2. Vacuum problems in Aachen plates solved ~ 4 mm vacuum chambers in the plate plate : sandwich of two Al-layers glued together with Araldite (everywhere !!) leaks leaks : vacuum under 1 sensor  some force under other sensor Lots of plates affected → Aachen has cured the problem on almost all plates (open plate and re-glue them together)

3. Bias in applied angle : review RMS ~ 1.7 mdeg applied angle : 100 mdeg These plots are made in July 2004 and where still valied in August. XY initial angle Due to some crash 2 years ago, the initial angle is lost. 

4. Bias in applied angle : review applied angle : 100 mdeg RMS ~ 6.2 mdeg regular intervals ~15 mdeg shift Now we have replaced the U-motor

5. Problem with rotation motor (U-motor) : new motor New U-motor installed → with the help of Marco Giorgi who came to Brussels First tests indicate we have the ‘sine-wave’ feature as observed by other labs… zero position Applied angle from zero position (mdegrees) The systematic shift is not constant. Fortunately we apply always the same angle between supply and assembly position. Hence this ‘sine-wave’ effect in negligible !!

6. Problem with rotation motor (U-motor) : new motor Pick-up and put-down precision with new motor (parameters re-tuned) RMS ~ 0.9 mdeg Very good precision Remember that the ‘sine-wave’ feature has little influence on this.

7. Summary Plates Plates Ê Vacuum problems solved on most of the plates Ë Supply plate to be adapted for alignment sensors this or next week Rotation motor Rotation motor Ê Motor replaced Ë (In)famous ‘sine-wave’ feature observed Ì Angular precision problem solved (good precision) R5S module production ¶ Hybrids send to UCSB as we had to deal with the U-motor problem Future (december – january) ¶ Start determining corrections for each plate with new U-motor J.D’Hondt