Machining compensation experiment – progress report

1. Machining compensation experiment – progress report J.Huopana 28.5.2008

2. Main idea • CAD/CAM-softwares are used to design the geometry and the manufacturing • Machining of the piece • Measuring the machined surface • Results of the measurements are analyzed and the reasons for the errors determined. Based on these findings a new geometry will be created in the CAD/CAM environment to compensate the found errors. • A new piece will be machined • Result: better accuracy compared to the first

3. Toolbox Experience & ideas Mitutoyo Series 355 Euro Apex Strato 9166 X-axis range 905 mm Y-axis range 1605 mm Z-axis range 605 mm Resolution 0.0002 mm Accuracy 1.7 605 mm Resolution 0.0002 mm Accuracy 1.7 µm Hermle C30U +/- 3-5 µm

4. Toolbox Experience & ideas Mitutoyo Series 355 Euro Apex Strato 9166 X-axis range 905 mm Y-axis range 1605 mm Z-axis range 605 mm Resolution 0.0002 mm Accuracy 1.7 605 mm Resolution 0.0002 mm Accuracy 1.7 µm Hermle C30U Hermle C30U +/- 3-5 µm

5. CAD/CAM design Test piece • Shape has been extracted from VG1 (CLIAAS110001) • Green surfaces are designed for metrology • Shape tolerance goal better than +/- 5 µm • Modeled in CATIA and in MasterCAM

6. Machining • 5-axis machine • One axis is used to tilt the test piece to have more material to remove • After the tilting (5 deg), machining is 3-axis • the machine is stabilized (respectively) • Air condition, 6 hours of operation before starting the machining

7. Contact Measuring Machine • Five profile measurements • 45 deg profile (shape1) • Profile from the right (shape 2) • Profile from the left (shape 3) • 45 deg profile to the opposite direction (shape 4) • Profile from the bottom of the cell • (shape 5) Shape 4 Shape 5 Shape 1 Shape 2 Shape 3

8. Tests • 2 main strategies to machine the piece (surface) • Both were machined and measured to determine the ”right” method

9. Test piece 1

10. Iris 2

11. Cross-section

13. Test piece 1 • surface quality, considering Ra 0,2, is not achievable with current cutting speed of 18000 rpm (not a goal in this study) • problematic connection of surfaces visible, might be possible to fix with changes in CAM • burrs visible, also possible to improve the situation by changing CAM-design

14. Test piece 2

15. Test 2, Iris 2

16. Cross-section

18. Test piece 2 -changes were made for the tooling directions and movement to have smoother surface in the iris area and to remove burrs -changes were made according the first test -a error of 6 µm visible in every shape => Tool length (0.006 mm)

19. Test 2 + 6µm (y) (simulation)

20. Test 2 + 6µm (y), Iris 2 (simulation)

21. Test 2 Cross-section + 6µm (y)

22. Results of the first two tests

23. What happens when you compensate to the wrong direction?

24. What happens when you compensate to the wrong direction? This Test 3

25. What happens when you compensate to the wrong direction? This Test 3 MURPHY'S LAW §15. ”In an instrument or device characterized by a number of plus-or-minus errors, the total error will be the sum of all the errors adding in the same direction.”

26. Test 3 - 12µm (y) (simulation)

27. Future work • Compensate the tool length • Compensate the bending of the piece • Measuring and verifying the effectiveness of the method

30. That’s all folks.