Anyone Having success Measuring very small radial features??

[MJBolster]

I was hoping that the machine/software package(Global Image 7-10-7, 3.7MR3) could verify the odd features and locations thereof that we encounter everyday around here. Very short larger diameter cones where the length is less than 10% of the diameters. But I'm realizing that these things may be mathematically unfeasable.
I'm sure that experienced programmers each have their bag of tricks-
I certainly am in the market for some. Since 2006, even I have some
ways to "do" the "undoable" with fair certainty.
I think, in general that I've been forced to realize that CMM is not the silver bullet for every situation that I was hoping it was. Maybe a different
CMM/Software combo??
I enjoy the challenge of doing what others say can't be done, but most of the time my tongue is hanging out with little to show for it.
I've never been a drinker,but................................

Tks
Mike

[Paul Sarrach]

Have you looked into QuinDos? It is high end and not user friendly ( workable) but I believe it is what you are looking for.

[Wingman]

I was hoping that the machine/software package(Global Image 7-10-7, 3.7MR3) could verify the odd features and locations thereof that we encounter everyday around here. Very short larger diameter cones where the length is less than 10% of the diameters. But I'm realizing that these things may be mathematically unfeasable.
I'm sure that experienced programmers each have their bag of tricks-
I certainly am in the market for some. Since 2006, even I have some
ways to "do" the "undoable" with fair certainty.
I think, in general that I've been forced to realize that CMM is not the silver bullet for every situation that I was hoping it was. Maybe a different
CMM/Software combo??
I enjoy the challenge of doing what others say can't be done, but most of the time my tongue is hanging out with little to show for it.
I've never been a drinker,but................................

Tks
Mike

PC DMIS consistently tops the charts for accuracy and repeatability of CMM Software Programs.

With that said, calculating a radius from a small section is virtually impossible if the points takes were 100% accurate.

Use Profile. A trick to use when you cannot get Engineering to switch to profile is to translate your Origin to the theoretical center of the radius and take radial points (polar Vector points) along the surface. Report the MIN and the MAX Radial Distance.

Best is to get Eng to swith to profile

[Underspec]

If your engineers want you to check radii have them give you the coordinates of that radius from the datum and take points then do polar distance.

[MJBolster]

Unfortunately the engineers responsible for our designs have probably long retired from the Govt. The engineers in charge of the programs have little to do with the engineering. We are the receipt inspection dept. We simply want to verify that the hardware and assembly parts that are purchased for our programs meet the dwg. specs. We have to deal with 50 years of shifting GD&T standards and very strange drawing callouts.
Its a semi secure job but a really weird environment.

MJB

[Underspec]

Well there's always radius gages

[MJBolster]

Most of our "obsure" (for want of a better word) features also have positional callouts- my radius gages are the cheap kind - they can't do that very good-
or, maybe I just need more practice

MJB

[Wingman]

Most of our "obsure" (for want of a better word) features also have positional callouts- my radius gages are the cheap kind - they can't do that very good-
or, maybe I just need more practice

MJB

With a positional callout you have ALL you need.

Translate Alignment to Theoretical Center.
Measure Radial Points.

The tolerance (accept / reject) for the radial points is as follows:
± 1/2 the True Position + the Radius Size Tolerance (IF Callout is RFS)
OR
Same as Above but the PLUS tolerance gets TWO Times the Radius Size Tolerance with MMC


That will cover a TRUE Position and a Radius with +/- tolerances.

[MJBolster]

TKS Bill--

MJB