Creating different strategy for features in the same measurement plan - STL part to measure

[[Au...]]

Hello friends,

I'm trying to create an automatic measurement plan starting from a CAD file with PMI included - see files in attachment. All this on a scanned part, STL file

the biggest problem I face is that when I'm running the measurement plan created automatically from PMI I have many features which are not calculated correctly: points outside interested area, lines on edges...etc

I had chose a general strategy from "resources-save/ load default" but does not fit all features: some planes are much larger than others and an grid strategy which is good for a big plan does not go to a small plan. Or for a cylinder. Of course they can be corrected manually.

So, is there any way to to somehow set a measurement strategy which can be programmed according to feature to be calculated? I can create different strategy's, planes for examples, in the same measurement plan? or maybe you can give me some advise...

I haven't had yet a discussion with the designer who created this PMI, maybe some problems could be improved (will follow)

there is someone else who works with PMI? maybe we can share our results 😎

Thank you

grid on plane - not OK.JPGCAD with PMI .JPG2d line5 on STL.JPG2d line5 on CAD.JPG

[[No...]]

The variable strategy editor (Extras -> Settings -> Variable startegy editor) might be able to do part of what you need. I can't provide you with any advice however, as I'm currently preparing to move from Calypso 2018 straight to 2021, so I had no chance to try it out yet. But the description sounds as if it can adapt strategies to feature size.

However, issues like lines being placed on edges are not a strategy problem. These have to be taken care of by modifying the nominals. Since we don't use PMI in our models, I can't give you any advice here either. I suppose that either your designer has to change the PMI definition or you'll have to correct such features by hand. I'm not aware of a way to define a line strategy that is offset from the nominals (that is, only along the direction of the line, but not "sideways")

[[Au...]]

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great advice, thank you. I'm using 2020 version, variable strategy editor is incorporated

[[Me...]]

How did you get the STL in Calypso? I wasn't aware of that ability!

[[Ow...]]

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Exactly!
I'd be very interested in knowing what type of scanner was used to create the model and what software was used to make the STL with PMI? Every scanner I've worked with leaves a lot of junk that is very time consuming to correct in 3D cad software.

To your questions, I haven't worked with PMI or the variable strategy editor Norbert mentioned and that may be the way to go. If you knew the exact size of feature before running the program you could use mini-plans.

[[Au...]]

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I'm using a scanner from Zeiss, COMET: https://www.zeiss.com/metrology/product ... lin3d.html / it's true about junk, a lot of light reflexions that must cleaned. With this software - Colin 3D - after you make the alignment with CAD, you can cut what is outside CAD (you must set a few mm in plus).
The PMI is integrated in 3D drawing not in STL. in my example is a .prt file and I think was done with CREO by designer

[[Au...]]

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after I make the scan with this equipment https://www.zeiss.com/metrology/product ... lin3d.html in measurement tab it is window "STL Setting" where the STL file can be imported like you import a CAD file. after you align the CAD with STL and perform measurements with high points density

[[Ri...]]

You have to have the Calypso Manual option to be able to use STLs natively.

You also have to setup your machine as an STL.

In addition, you can create a Point Cloud, bring in your STL, and then when you extract your features, tell it to use the STL instead of the CMM. See below.

Having said all of that - Calypso isn't really the best tool for inspecting an STL file. Since Zeiss has acquired GOM, I would recommend using GOM Inspect. The free version is extremely powerful.

[[Au...]]

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Calypso work's fine with STL files, but regarding the scanning equipment... yeah, GOM seem's to be the right choice. I'm very discontent with Comet from Zeiss. I'll probably go for it, at least for the scan

[[No...]]

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😱
This feature must be in there for at least 4 years now. But I agree, it is well hidden.
I don't know if you need the MAN option for it to work, all I know is that it definitely doesn't work on an offline seat.
Funny fact, I set up an STL machine on all of our CMMs a few years ago, but then we bought a GOM scanner and I never used it (the Calypso feature) since then. I refuse to even imagine how gruesome it must be to evaluate anything useful out of an STL with Calypso. Considering how many parts we measured with GOM in the last few years, I guess if I'd have had to do all of this with Calypso, you could now visit me at the nuthouse 🤣
I guess Zeiss knew very well why they bought this company - and why they ditched the Comet scanners (or did they? At least I find no more reference to them anywhere on the Zeiss site.).

[[Ri...]]

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It works fine sure, but the problem with using STLs with Calypso is that you still have to setup all of your strategies, and evaluations. Calypso was designed for CMMs, and STL integration was later added.

GOM Inspect was designed for STLs. 🙂

[[Au...]]

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I didn't know that, so we were fooled because we don't have a CMM... only the scanner 🤣 I installed GOM on my workstation, need to learn it

[[Me...]]

I didn't realize everyone was talking about the Vision systems...So theres that.

[[Ri...]]

It's not a vision system. The Comet was a blue-light scanner. It works off the principle of fringe projection. Pretty neat technology.

We had a Comet for a couple of years - it was an amazing machine. We now have a T-SCAN Hawk which is also awesome to use.