Self-Center Probing

[[Cl...]]

Can someone tell me if this is correct?

My print nominal is; 0.788 to the intersection of the cylinder and cone. I'm using a self-centering point locking X&Y.
Is it simply a matter of probing the point, entering the print nominal in the point, then does Calypso use the nominal
CAD data (cone angle/depth) to calculate the result?

[[Mi...]]

You're probing a point, Calypso doesn't know its a cone anymore. If it's a critical depth and you can measure the cone, measure the cone... but if the cone is too small to measure do something like this.

Do the math to figure out the distance from the mid point of your probe to the effective depth of the hole. 0.722556 in my example

Measure your self centered point, set evaluation to mid point.

Use a result element to add both values.

Note: This assumes the drill point angle is always good, and doesn't change, dangerous if the tolerance is tight. The way to avoid this would be to measure the cone... but if that could be done in my example I wouldn't need self centering points. I periodically re-trace the angle of the holes and adjust the values based on the new results. They like to make tooling changes without informing me, the example here used to be a standard 120 degree hole.

Blind Hole Depth.PNG

[[Jo...]]

I wouldn't clamp any axis, that defeats the self centering. Michaels method is what I use to get drill point depth.

Another crude method to get the full diameter intersection:
Select a gage pin that fits, then meaure that depth with caliper or micrometer. Use the difference in your result element formula.

[[Cl...]]

Works great, thanks guys!

[[Da...]]

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What should clamping be doing anyway?

[[Jo...]]

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I believe it restricts that axis. In his case, if the hole were not in nominal x,y position the probe would travel in z until it touched. With all 3 axis available it would follow the slope down until maximum z travel was reached. I haven't read the documentation in awhile.

I've used a large stylus diameter to find the location of very small holes with this method, then used the coordinates to send in a very small stylus to measure without risking breakage.

[[Jo...]]

[[Ri...]]

Clamping is great if you are self-centering inside of something like a spline or gear tooth. I typically will restrict the height axis (typically Z), so that it doesn't try to "walk-up" the feature.

In your case, you would not want to restrict any axis as you are trying to the find the low point based on finding the center, so you need to "hunt" in all three axis.

I also suggest to always use mid-point for the point evaluation for self-centering points. In addition, you might try to increase the probing force to ensure that you are accurately finding the bottom.

[[Cl...]]

Thank you for all the help everyone!