Scanning is less accurate because too much data confuses Calypso....

[[Ca...]]

I hear this one or two times a month. It's obviously nonsense.

Does anyone else have this problem?

[[Ch...]]

No but I wish I did. If I worked around people this stupid then I'd make up all kind of things Calypso can and can't do. Calypso doesn't work on Saturdays.

[[Ke...]]

Nope
..if it's true, Zeiss has a *terrible* business model 🤣

[[Jo...]]

It doesn't take a statistician to figure that out. Obviously a 2 point caliper measurement is superior to using 3 or 4 or 9992 data points.

[[Me...]]

I'm guessing an Engineer said this?

[[Ün...]]

Don't be surprised if the engineer in the production department said.

[[Jo...]]

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I had this demonstrated as the root cause in a production process. We had some parts that had bad form (6 lobed) from being clamped in 3 jaw chuck. They then went to mill for bolt pattern in flange. Mill probed in 4 places to find center, and ALWAYS had a true position error.. They needed a divisor by 3 to properly center the mill..

[[Ow...]]

Once upon a time in a different company, 15 years ago we replaced our touch trigger single points CMM with a Zeiss scanning CMM. We had over 3500 programs to convert/replicate so, in the transition we kept the touch trigger CMM checking everything until programs could be made on the scanning CMM. This took about 2 years and we kept the single points CMM around to check stuff when the scanning CMM was busy checking other stuff.

There were several instances where we were finding stuff we thought was good and used to use that was actually not-good because of distortion/bad-form.
During the transition when we checked parts that were rejected on the scanning CMM, production would ask us to check the same part on the single point CMM to see if it was good. 🤣
Needless to say, we ended up improving a lot of machine and fixture problems and ultimately had less troubles in assembly of product, less 2nd article checks because the production process was now more repeatable and less warranty.

[[Ri...]]

There is definitely truth to this for some cases.
Take Step Points for instance.
Too much scan data can and will cause errant values, it can crash Calypso (Hang forever).
I have ran into this far too many times using Step Points and its related features having too much data.
I've seen results vary by over .050 (inch) and location results (True Position) off by an astounding .400 (Inch) plus.

I was just working on this today.
Two features, each 2d Lines, had about 1501 points in a .180 (Inch) length.
The results were so far from consistent it became ridiculous to even consider if the result was good.
Then add the delay of upwards of 3 minutes per Step Point calculation, just to calculate a bad result.
Editing the 2d Line features to a .050 length and about 500 points has create stability in the reported results that now seem to match a manual layout within a high percentage of accuracy.

[[SH...]]

Scanning is very important for me, my customers are demanding scanning. They came to my plant and changed the program to scanning , one time I remember.

If there any brainstorming problem my Production people came to CMM room and ask the part to scan and give the graph to them ,to understand the root cause.
If we use proper strategy and evaluation scanning will not give bad result, I think.