Making Scans Parametric

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  • Making Scans Parametric

    I was interested in finding out if anybody has managed to make scans parametric in a PCDMIS program. I have 10 sizes of part that all have different types of scans, all scanning from the nominal Cad file. I can make all the prismatic features parametric by using external text files, but not the scans, which I have to adjust by programming each one seperately. TIA
    3.7mr3CAD++ / 2011mr1CAD++/2012mr1CAD++/QUINDOS7

  • #2
    I have not personally made scans parametric exactly, but I have used automation to write the hits into the scan, and consequently have it measure whatever I want.

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    • #3
      Basic scans, all day.
      Only problem is certain fields cannot accept a typed variable, such as IN/OUT field in basic circle scan.
      If you truly need to vary between In and OUT circles then you end up making much more cumbersome branches with different features.

      I've got a program running at a customer that has dozens of basic line scans fully parametric for start, direction, end, boundary, IJKs, etc.
      The variables are calculated on the fly based on some input parameters. Works like a charm.

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      • #4
        Originally posted by Don Ruggieri View Post
        I have not personally made scans parametric exactly, but I have used automation to write the hits into the scan, and consequently have it measure whatever I want.
        Thanks Don, could you outline the basic process & script for reading the automation you are using?

        I think you can only read a file into a 'FreeForm Scan'. Is that what you mean. I possibly need to automate Linear open, Patch Scans and also Freeform as well.
        3.7mr3CAD++ / 2011mr1CAD++/2012mr1CAD++/QUINDOS7

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        • #5
          Originally posted by Josh Carpenter View Post
          Basic scans, all day.
          Only problem is certain fields cannot accept a typed variable, such as IN/OUT field in basic circle scan.
          If you truly need to vary between In and OUT circles then you end up making much more cumbersome branches with different features.

          I've got a program running at a customer that has dozens of basic line scans fully parametric for start, direction, end, boundary, IJKs, etc.
          The variables are calculated on the fly based on some input parameters. Works like a charm.
          Thanks Josh - No it's not basic scans based on geometric features.

          Its Linear Open, Patch, Freeform Scans etc...used to check various surfaces on the parts, some surfaces being checked are flat planes (so maybe basic lines, constructed into sets might work, but patch scans seems less code in the program), albeit at compound angles, but some are freeform surfaces, curved in all directions.
          3.7mr3CAD++ / 2011mr1CAD++/2012mr1CAD++/QUINDOS7

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          • #6
            I did it with Linear open scans myself. My example is too fragmented and project specific, meaning it would take me too long to make it meaningful for you to follow. I think the best way to start is to write a simple measurement routine with nothing more than maybe an alignment and a scan. Make sure you do not put too many points in the scan for this exercise. Then choose File - Export - BASIC. Save this (text) file and open it with notepad to check out the syntax. You can replace the scan XYZIJK values with your own variables to make it more parametric.

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            • #7
              Do you need/want them to be defined path scans or are you ok to use undefined(relearn) scans? Defined path can be done as Don describes where you use automation to stuff points into the scan. I recommend that you use freeform scans with this approach and then stuff in whatever scan path you want. Freeform scans have the fewest parameters to set and they can accept any path. There is a new scan command under the INSERT=>Modules menu called "FreeFormLine". This command can supposedly read in scan paths from external files during execution. I have never tried it.

              If you are ok with relearn scans you can do as Josh describes and just use a basic line scan and variablize all of the parameters. Then you read in the parameters for a specific part configuration from an external file and the scan executes based on these read in parameters. Many airfoil programs are written this way.

              Defined path scans execute much faster and are much more reliable in many circumstances so I tend to favor that approach over the relearn approach.

              One problem that you will run into is that if you want to use FINDNOMS there is no way to select which CAD surface to compare against using automation. I have asked for this ability as an enhancement but not available yet.
              2013MR1 SP6
              Global Frames, Tesastar-M Heads, LSP-X1M/H Probes

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              • #8
                Originally posted by DaSalo View Post
                Do you need/want them to be defined path scans or are you ok to use undefined(relearn) scans? Defined path can be done as Don describes where you use automation to stuff points into the scan. I recommend that you use freeform scans with this approach and then stuff in whatever scan path you want. Freeform scans have the fewest parameters to set and they can accept any path. There is a new scan command under the INSERT=>Modules menu called "FreeFormLine". This command can supposedly read in scan paths from external files during execution. I have never tried it.

                If you are ok with relearn scans you can do as Josh describes and just use a basic line scan and variablize all of the parameters. Then you read in the parameters for a specific part configuration from an external file and the scan executes based on these read in parameters. Many airfoil programs are written this way.

                Defined path scans execute much faster and are much more reliable in many circumstances so I tend to favor that approach over the relearn approach.

                One problem that you will run into is that if you want to use FINDNOMS there is no way to select which CAD surface to compare against using automation. I have asked for this ability as an enhancement but not available yet.
                I need them to be Defined paths (to many issues with Relearn, Scans). Just tried the freeform Scan method - was able to export both a linear open scan and a patch scan to XYZ files, clean up the files - then import them back into the freeform Scan and it worked - offline at least. Will it search for the XYZ each time, or just needs it imported the once?

                Tried the Insert Modules method - You import in your XYZ file to form a points list - then chose a free form path from the points or perimeter path from the same points, seems again to be working offline.
                3.7mr3CAD++ / 2011mr1CAD++/2012mr1CAD++/QUINDOS7

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                • #9
                  The scan functions within the auto features - in my case circle scan for autoplane - did not play well with variables. I guess your mileage may vary, but I never got it to work.

                  I needed the autoplane circle scan to be done on different heights, depending on the part. Using a variable for the Z-height for THEO Z, TARG Z and hit THEO Z didn't work. The scanpath never updated to reflect the new values, I had to F9 the scan and change a setting (any setting) on the tab where I can set the amount of rings, then it would "read" the variable and update the scanpath accordingly.

                  So, running the program and using different values for the Z did not work.

                  This is a major drawback compared to what it would be if it DID work.
                  PC-DMIS CAD++ 2o19 R1 SP11

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                  • #10
                    All scan commands store the nominal path internally. As long as you do not modify the command the nominal path will remain unchanged. You do not need to read in points for a freeform scan each time, it retains the last path that you read in. How do you plan to handle the nominals method issue? You can use Master if you just need to collect the data and don't care about evaluating deviation relative to a model. You can use FindNoms but unless your CAD is always the same you can't use the "only selected" option, which adds some risk that it could find nominals on the wrong surface.
                    2013MR1 SP6
                    Global Frames, Tesastar-M Heads, LSP-X1M/H Probes

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                    • #11
                      There should be a parametric feature built into PC-DMIS to handle parametric changes to the program features. Solid Works has an Equations, Global Variables, and Dimensions dialog box. Also an Excel add in module Design Table for Parametric design changes. Fusion 360 also has a built in Module for parametric design changes. Just more reasons for a new UI added to the list.

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                      • #12
                        There should be a parametric feature built into PC-DMIS to handle parametric changes to the program features. Solid Works has an Equations, Global Variables, and Dimensions dialog box. Also an Excel add in module Design Table for Parametric design changes. Fusion 360 also has a built in Module for parametric design changes. Just more reasons for a new UI added to the list.
                        ?? Variable parameters can be applied to nearly 100% of the scope of the software as it exists today. There are only a very few things that can not be dynamically modified via variable parameters. The selection of CAD surfaces is one of these things. Adaptive scans embedded in auto features is another.
                        2013MR1 SP6
                        Global Frames, Tesastar-M Heads, LSP-X1M/H Probes

                        Comment


                        • #13
                          Originally posted by davehocum View Post
                          There should be a parametric feature built into PC-DMIS to handle parametric changes to the program features. Solid Works has an Equations, Global Variables, and Dimensions dialog box. Also an Excel add in module Design Table for Parametric design changes. Fusion 360 also has a built in Module for parametric design changes. Just more reasons for a new UI added to the list.
                          Dave,
                          Could you spell out your vision for a 'built-in parametric feature' UI for an automated coordinate inspection system such as PC-DMIS?

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                          • #14
                            Originally posted by DaSalo View Post
                            ?? Variable parameters can be applied to nearly 100% of the scope of the software as it exists today. There are only a very few things that can not be dynamically modified via variable parameters. The selection of CAD surfaces is one of these things. Adaptive scans embedded in auto features is another.
                            Well, yes and no.
                            Two things about the current parametric system are that it only exists in the Edit Window and can only be interfaced with by manually typing in variable names to replace numerical values in fields. If you F9 an auto or measured feature that's had all that tedious work done to it - you see nothing but numerical values in the edit autofeature dialog.

                            In this system all the connections between the features and the variables are 'imaginary' or doodled on a sketchpad next to the keyboard. If you've ever had to open up a super-tricky parametric program that you've never seen before, you know that it can take forever to fully unravel the tangled web of relationships and branches that were probably crystal clear in the original programmer's (possibly over-caffeinated) brain. I usually leave plentiful $$ program comments in my tangled webs to alleviate that somewhat, but still the web construction process is tedious and can be broken with a single typo.

                            The problem is that we really can't take CAD Design 'parametric control' and apply it to our stuff. We need a system that's intuitive for the task of programming variable robotic movements around 3D objects chock full or varying hard reality, a system that allows parametric tree connections between inputs and moves, features, and dimensions - but with modifiers in each case if needed.

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                            • #15
                              Originally posted by Josh Carpenter View Post
                              Dave,
                              Could you spell out your vision for a 'built-in parametric feature' UI for an automated coordinate inspection system such as PC-DMIS?
                              Josh,
                              This depends on PC-DMIS UI. The current PC-DMIS UI this could be done with an added dialog window similar to the Mini Routines were the measured features or dimensions location and size is controlled by the Parts description.
                              Now if PC-DMIS was to have a new UI this could be applied in different ways and incorporated to flow of the UI. But still will change the program measured features or dimensions location and size by the Parts description.
                              Last edited by davehocum; 02-01-2016, 11:00 AM.

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