Question Regarding Radius and Profile

[[Ra...]]

Please view the image file.

Can i achieve this radius as shown by measuring a profile of the line in the desired area.

or

What is the best way about achieving this measurement.

1.jpg

[[Ji...]]

Having it toleranced for your profile is the best bet. You can pull the radius out by using recall in a new circle and lasso the points. If you are not getting at least 45 degrees of the 360 degrees to make up the diameter your results will not be very accurate. We just had a Zeiss pro in last week over this very issue. He said what I had being telling our engineers all along. Those cases is why curve was invented.

[[Jo...]]

So the banana shaped or crescent tolerance zone discussion should begin any time...

[[Ra...]]

When I define circle on cylinder on the above shown area where the arrow points. I take the radius measurement characteristics, use the circle. As nominal the value displays what im looking for 72.5. But when i go to actually measure its way out of spec 100+.

Any advice?

[[Ri...]]

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Short arc radii will require you to constrain the location to get a better approximate of the radius. If you are already measuring a Curve on there, here are some things that I have done that I've had pretty decent success.

- Measure the feature as a Curve
- Inside the Curve, turn on Best-Fit, and create an Alignment from that Best Fit
- Measure a Circle at the same height as your Curve on that surface
- Use the Curve Best-Fit Alignment as the Alignment for the measurement
- Only measure 3-4 single points on the surface
- Constrain the Location (X,Y,Z) of the Circle
- Evaluate the Radius
-Good luck