Reporting hole size

[Sean Steele]

OK, joking aside, I need to know how dmis figures the size of the measured hole. I believe it is a best fit calculation, correct? Is there a way to get it to report the min, such as when you put a gage pin thru the hole? I am currently measuring an assembly that has two halves. Each half has matching holes that don't totally line up. Since this part is bolted to another part, the engineer wants to know what size the thru hole is perpendicular to the part axis. My original thought was to take several hits on each part and project them to a nominal plane then construct a circle. Now I just need to know how to report the min dia of the hole.

[NZ CMM Girl]

When you construct your circle from the points, click the Best Fit radio button and choose MAX_INSC (maximum inscribed circle) from the drop down menu instead of LEAST_SQ. This will give you the maximum diameter that will go through the hole. If you were measuring a stud, and wanted to know the smallest hole that the stud would go into, you would use the MIN_CIRCSC (minimum circumscribed circle) option.

[rangerboat72]

When you construct your circle from the points, click the Best Fit radio button and choose MAX_INSC (maximum inscribed circle) from the drop down menu instead of LEAST_SQ. This will give you the maximum diameter that will go through the hole. If you were measuring a stud, and wanted to know the smallest hole that the stud would go into, you would use the MIN_CIRCSC (minimum circumscribed circle) option.

Right on the money...

[Sean Steele]

Thanks

Thanks NZ

New question same situation. I am using several hits at different levels inside the hole. I am using edge points so that the machine compensates for the location of the surface the hole is in. Is there a way to reference the surface sample of the first level then measure the second and third level. Taking a new sample hit every time makes the program run too long. I thought about setting the axis origin to the sample hit then taking the other levels but I don't want to mix alignment types since I am already using an iterative alignment in the program. Using an auto cylinder won't work because it won't be perpendicular to the cad nominal surface.
I would post my code but one hole worth of code is over 10000 characters.

[Paul Sarrach]

Can you construct a plane then 3D intersect the points to it?

[Paul Barriage]

In your autocircle box, do you have 'relative features' on the left about halfway down??

Reference the other levels to the first. 3 sample hits on the first would be better though.
http://baggy3.info/2centani.gifhttp://baggy3.info/signani3.gif

[Sean Steele]

Paul, I am using individual points. I will have to check on the relative feature thing. I would love to be able to take a surface hit on the first point of the level and then reference that for the point on the next two levels. Thanks for the insight. I will let you know if it works.