1. Girders fabrication: Difficulties to achieve tolerances and machining process Igor Madariaga (ESS-Bilbao) 13 September 2011 DTL mini-workshop, CERN

2. Outline 1.Introduction to DTL 2.Girder´s properties 3.Girder´s new machining process 4.Improvements of the new machining process

3. Introduction to DTL Main Parts of the DTL –Drift tubes –Tank –Girder

4. Introduction to DTL Parts –Drift tubes –Tank –Girder Drift tubes

5. Introduction to DTL Parts –Drift tubes –Tank –Girder Tank

6. Introduction to DTL Girder Spend time machining the girder avoid post - alignments

7. Girder´s properties Girder main functions: –Fix the position of the DTs with high precision Material –Aluminum EN AW-5083 H111 Dimensions –1924 x 150 x 177 mm 2 machining process –The old one does not achieve the tolerances between critical holes

8. Girder´s new machining process Main parts of the process –Rough milling Leaving 5 – 6 extra mm for each dimension –Stress releve Thermal treatment –Pre finish –Finish

9. Girder´s new machining process Rough milling –Machine: Centro mecanizado Soraluce –Be sure not to introduce any linear or torsional deformation Test with dial indicators –Avoid heating of the milling zone –Use 4 supports and 4 clamps Large quantity of coolant

10. Girder´s new machining process Definition oh holes and faces Stamp holes Top face Cooling holes Left/right face Fit into the tank (Girder key) Bottom face Girder key Hoist points

11. Girder´s new machining process Rough milling –Square the part to obtain parallel faces –Drill stemp and cooling holes (ø50 and ø40) –Mill girder key(80) Old machining process

12. Girder´s new machining process Pre finish –Machine: Mandrinadora SACEM-530 Precision: +/- 0,01mm –Control room temperature +/- 0,5° C to avoid thermal dilatations. –Be sure not to introduce any linear or torsional deformation Test with dial indicators –Use 3 supports and 3 clamping points (L/5 and in the middle)

13. Girder´s new machining process 3 supports and 3 clamping points supporting the part in top face –Finish-mill ø35 pocket –Tap M-12 screw holes –Finish-drill ø40 holes cooling holes –Pre-Finish face B Old machining process First low tolerance dimensions After high tolerance dimensions Top face Right face Hoist holes

14. Girder´s new machining process Turn table 180 ° –Finish-mill ø35 pocket –Tap M-12 screw holes –Finish-drill ø40 holes cooling holes –Pre-Finish face C Top face Left face Hoist holes

15. Girder´s new machining process 3 supports and 3 clamping points supporting the part in right face –Rough-mill 15k6 to 15,5mm –Rough-mill 80h6 to 80,5mm –Finish-drill ø12,5 holes –Tap hoist drills M-12 –Finish-boring ø49,5 –Finish-boring 50 H7 –Pre-finish face A Old machining process Girder key Stamp holes Right face Bottom face Hoist holes

16. Girder´s new machining process Turn table 180 ° –Finish-mill ø42 pocket –Rough-drill ø10H7 to ø8 –Finish-drill ø14 holes –Finish-mill ø35 pocket –Tap M-12 screw holes –Finish-mill ø70 –Finish-boring 50 H7 –Pre-Finish face D –Insert the bushes Old machining process Stamp holes Right face Top face Hoist holes

17. Girder´s new machining process Finish –Machine: DIXI 5S –Dimensions: Axis X 2m Axis Y 2m Axis Z 1m –Precision: Flatness 0,002 – 0,003 mm / 2 m 0,001 mm distance between holes Turn 0,0002 °

18. Girder´s new machining process Finish –Control of the temperature of the room +/- 0,25° C to avoid thermal dilatations. –Be sure not to introduce any linear or torsional deformation Test with dial indicators –Use 3 supports and 3 clamping points (L/5 and in the middle)

19. Girder´s new machining process 3 supports and 3 clamping points supporting the part in top face –Finish-mill face right face to high tolerance Reference face 3 supports and 3 clamping points supporting the part in right face –Finish-boring ø10 H7 –Finish-mill face D Top face Right face Right face Top face

20. Girder´s new machining process Turn table 180 –Finish-mill 80 h6 –Finish mill 15h6 –Finish-boring 40 H6 and 39,8 H6 Girder fit Stamp holes Right face Bottom face

21. Improvements of the new machining process –Better machine, with better tolerances –Temperature control: Better control of the room´s temperature Better temperature control in the milling zone Really important to avoid thermal dilatations –Different machining process Don´t leave the small drills for the final

22. Girders fabrication: Difficulties to achieve tolerances and machining process Igor Madariaga (ESS-Bilbao) 13 September 2011 DTL mini-workshop, CERN