Straightness measurement using auto collimatorFull description
FLATNESS MEASUREMENT
ALEX P.M. 0206
FLATNESS ?
FLATNESS ?
Flatness measurement : jackscrew method
Jackscrews are preleveled using a height gage .
Part is mounted on jackscrews jackscrew s
jackscrew method :
Part surface has been leveled to the surface plate. Comparing the surface to
Flatness measurement : wobble - plate method
Leveling Wobble plate in use.
Flatness measurement : fixed - plane method
Part resting on three equal pins.
FIM being obtained from the inverted surface.
Flatness measurement : direct - contact method
Direct - contact method Mastering the probe with a precision parallel
Inspecting the part.
Optical flatness inspection
Viewing the bands on the surface of the part with a optical flat.
Optical flatness inspection
Wedge method
Contact method
Interpreting the Bands for Flatness Error
Straight, parallel & equally spaced bands shows that the surface is flat.
One band of error equals 11.57 millionths out of flatness.
Interpreting the Bands for Flatness Error
Concave : out of flat by 2 bands.
Spherical concave : out of flat by 2 bands
Interpreting the Bands for Flatness Error
Spherical convex : out of flat by 2 bands (23.14 millionths).
Peaks & valleys : out of flat by 5 bands (57.85 millionths).
STRAIGHTNESS MEASUREMENT
ALEX P.M. 0206
STRAIGHTNESS ?
STRAIGHTNESS MEASUREMENT
Axis Vs surface element straightness
Straightness of surface element : cylindrical parts
Straightness of surface element : jackscrew method
Jackscrews are preleveled using a height gage
Establishing zero on the part surface at one end.
Straightness of surface element : jackscrew method The indicator is traversed along the surface elements of the shaft (at the top dead center) for straightness error measurement
Straightness of surface element : Precision straightedge method
A precision straightedge can be used when tolerances are relatively loose.
Straightness of surface element : Comparator method
Straightness of surface element : Two - Block method
The part is placed on top of two equal height blocks.
Dial indicator indicates line elements of the surface.
Straightness of surface element : Noncylindrical parts
Jack screw method Precision straightedge method Conical parts
