Gaging Exploration (Applications)

Transcription

1 Gaging Exploration (Applications) PMPA Technical Conference Tomorrow is Today - Conquering the Skills Challenge Chicago, IL April 24, 2018 Gary K. Griffith Corona, California

2 Gary K. Griffith 50+ Years Experience Automotive, Aerospace, Medical Engineering Manufacturing Quality ASQ Hromi Medal 2018

3 Reference

4 Most Challenging Dimensional Inspections Geometric Tolerances Equipment CMM Ferrell Arm Surface Plate Setups Functional Gages (I/A) Comparators (limited) Vision Systems (limited)

5 Your Ability to Inspect Products Your ability to inspect a product depends on: The skills of the Observer Blueprint Reading & GDT Measuring & Gaging Equipment The equipment at hand

6 Setups include Surface Plates and Accessories Parallels Blocks Gage Blocks Knee Precision Vise Sine Plate Surface Gage Height Gage

7 Flatness Optimum plane setup Jack screws shown Once leveled, F.I.M.

8 Flatness Fixed plane method Three Indian Pins (equal height) F.I.M.

9 Circularity (Roundness) V-Block Method Use correct V angle Rotate the part on itself Use the equation to correct the F.I.M. value V ANGLE = n Circularity Radial;.003 = = = FIM 1+ Csc A

10 Circularity (Roundness) Rotab Method Check jaw runout with a gage pin (10% Rule) Put the diameter in the jaws Rotate the part for a F.I.M.

11 Straightness Surface Elements Each line element must be straight Jack screw setup levels the part at top-dead-center (each end) FIM using top-dead-center Zero Set (each end) readings

12 Straightness Surface Elements Each line element must be straight within.002" Measurement is a F.I.M. Two equal gage block stacks establish the optimum line Move in and sweep across another straight line

13 Parallelism Offset Datums Offset Multiple Datums Surface plate contacts A Gage block contacts B F.I.M. Measurement

14 Parallelism Multiple Datums Multiple datum Inspect the datum profile control first Surface plate contacts high points Surface plate simulates datum plane A F.I.M. Measurement

15 Parallelism Hidden Datums Datums are offset Two blocks (shown) (or twin parallels could be used) Mount datums on blocks F.I.M. on the surface

16 Parallelism of an Axis The axis must be parallel to datum A Using a slip-fit gage pin, measure the F.I.M. Zero Set Difference

17 Parallelism Axis to Axis Slip-fit pin in datum A Datum pin in the V-Block Zero at one end on top-deadcenter Setup See the difference at the other end Check other directions Zero Set Difference

18 Perpendicularity Only datum A is mounted F.I.M. is best fit Rotate part (clockwise / counter clockwise) until smallest F.I.M. is found

19 Perpendicularity Mount datum A Right angel plate aligns datum B F.I.M. across the entire surface Part is aligned, no manual alignment is necessary (or allowed)

20 Perpendicularity Surface to Axis V-notches in precision vise establish datum B Rotate the setup F.I.M. on the surface

21 Perpendicularity Slip-fit gage pin in the hole Part datum A mounted on a right angle plate Top-dead-center readings over the distance Check again in a different rotation Zero Set Difference

22 Perpendicularity Axis to Axis Slip-fit gage pin in datum A Datum pin mounted in V-Block V-Block setup rotated Find zero at top-dead-center on one end Measure the difference at the other end Zero Set Difference

23 Angularity A Sine Bar (shown) or Sine Plate Mount datum A on the Sine Bar Setup the angle using the sine of 30⁰ times the length of the bar F.I.M. across the entire surface Rotate and sweep for best fit F.I.M.

24 Circular Runout Tri-Roll (shown) or V-Block if necessary to mount and rotate the part on datum A F.I.M. at the surface of circular sections

25 Circular Runout Slip-fit gage pin simulates datum A Pin is resting in matched V s Part is rotated on the simulator F.I.M., at different circular sections, must be equal to or less than.001"

26 Circular Runout V-Block mounts datum A Dial indicator is placed at on circular section Part is rotated for F.I.M.

27 Circular Runout - Counterbore Datum A is pinned Pin is resting in the Tri-Roll Dial indicator is placed at one circular section Part is rotated for a F.I.M. Move to another circular section and repeat

28 Total Runout Datum mounted Indicator must traverse across One F.I.M. value for entire surface

29 Total Runout Datum is in the Tri-Roll Indicator (guided) on top-deadcenter (TDC) Indicator is traversed while part rotates TDC Traverse

30 Profile Datums - Comparator Contour profile with two datums Comparator stage moved up to align with horizontal crosshair Right angle plate (on the stage) moved over to align with vertical crosshair Stage is then indexed away by the basic.190 dimensions

31 Profile Datums - Comparator Overlay is placed on screen and lined up with crosshairs Part is mounted on stage and against right angle plate Index into zone This part is out, rejected

32 Profile - Coplanar Level three points on both surfaces using jack screws Once level, find the F.I.M over both surfaces

33 Profile - Coplanar Part datum is mounted in a setup Indicator is set at zero on the simulator Run indicator across the Zero surface for a This is not a F.I.M.

34 Concentricity Differential measurements required to find axis eccentricity ( E ) Two opposing indicators Rotate the part to find E Very problematic measurement

35 Symmetry Differential measurements Measure from both sides to find the centerplane symmetry error (E) Centerplane cannot deviate from datum A more than.002 in either direction M2 M1

36 Position Three Datums Mount datums A, B, and C using simulators Measure each coordinate and find the deviations Calculate the actual cylindrical zone Bonus tolerance may be available

37 Position - CMM Probe the simulators Mount datums Measure the coordinates Allow appropriate cylindrical zone (with bonus I/A)

38 Position Surface Plate Setup Mount datums against simulators Measure coordinates Calculate actual zones

39 Position Best Fit Lower frame inspection CMM Either CMM or a Surface Plate Setup Measure directly from axis to axis Best fit the data Surface Plate Measure

40 Position Best Fit Inspection is complete Data (deviations) recorded

41 Position Best Fit Lower frame inspection Paper gage shows that the part is acceptable (best fit)

42 Questions? Need Training?