Reporting Sphericity

[gibsonridge]

im not finding a way to report Sphericity in pc-dmis
i need to evaluate the form of a sphere. am i just missing it ?

[Sora5]

"The Insert | Dimension | Circularity menu option determines the roundness of a circle, sphericity of a sphere or the conicity of a cone."

Per the PCDMIS help file.

[InspectorJester]

I had imagined it would be a Circularity dimension, but I was not able to research or provide any facts...
+1

[gibsonridge]

the best thing i have come up with is to measure a sphere, datum it x,y,z then report the center point distance to each point measured around the sphere.
thoughts ?

[Schrocknroll]

the best thing i have come up with is to measure a sphere, datum it x,y,z then report the center point distance to each point measured around the sphere.
thoughts ?

Or you could use circularity which will check the sphericity of the sphere as Sora5 mentioned. I've tried it and it works.

[InspectorJester]

Have you tried it?

[gibsonridge]

yes , and im still tinkering trying to get the best definition , to give the operator the best definition of true form.

[gibsonridge]

when viewing the graphical it appears to be evaluating the circularity of a diameter (2D) in the current working plane only.
i need to see the error in a 3D , basically im trying to check a qual sphere.

[michaelwildschutz]

You can dimension the Form only of the sphere and even show it graphically if so desired

[Mike Ruff]

What type of probe are you using? If it's a TP20, I highly doubt you'll be able to get down to .0004" Form because the springs cause error, so I switch out the TP20 for the scanning head here when I need very high accuracy

[gibsonridge]

tesa Star leitz scanning head,
i found that a two mm probe is giving me the best results. ( proofing it all out on my qual sphere.)
reporting profile of a surface - form and location checking at .000027" on cmm qual sphere

[InspectorJester]

Well done!