Night Shift Blues !!

  • Filter
  • Time
  • Show
Clear All
new posts

  • Night Shift Blues !!

    Can any of you guru's out there help me out, not sure if I am just having a typical nightshift meltdown or I have a problem with PC Dmis

    I have a simple part which I have aligned to both manually and in DCC mode using itterative alignments and everything works fine. I then perform a patch scan on the flat face that is my level plane using the following criteria

    Direction 1 Tech - Nullfilter
    Nominals - Findnoms
    Execute - Relearn

    I am using a CAD model and a 4mm dia probe so have set the find noms tol at 3mm.

    When I run this offline everything is OK. When I run it online it stops and I get a message which says PC Dmis cannot find nominals for the hits it has taken and do I want to change the find noms tol, if i just accept the 3mm value I already had the program runs and the scan is within 0.025mm all over which I would expect as this is the datum.

    I cannot understand why

    a) It cannot find nominals for the hits but will if I accept the same value it is questioning
    b) It asks this every time I run the program

    PC Dmis V3.7MR3
    Global Performance 7-10-7 using SP25M

    4.30am in the morning and my head is done in, help


  • #2
    When you mark the surface to scan on the model,are'nt you already finding the NOMS for each hit? I myself just got off nights. I worked them for ten years.


    • #3
      Well, if you have CAD data, do NOT use FINDNOM or RELEARN.

      FIND NOMS is for use when you CHANGE the cad data to a new revision
      RELEARN is not really for checking, but for reverse engineering.


      Then, once you have defined your boundaries, click on GENERATE and Pcdmis will pull all the XYZIJK values from the cad data and you are set to run.
      Originally posted by AndersI
      I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.


      • #4
        Scanning blues

        I have the same issue with the patch scans and using a constant touch probe finding the nominals...I dont know the answer. Matts post was telling you to use a regular touch probe..Using Matts idea will work and you wont have the issues that you are currently having. As for the patch scan and an SP25 I think that it is a software issue. When I have this issue, I end up making a sieries of linear open scans and creating a feature set.
        "You cant vote 'present' as the President of the United States"


        • #5
          Thanks for the replies all

          Matt - Maybe I am wrong but when scanning with a constant touch probe such as the SP25M my understanding was the CMM collected the data and then went back and pierced the CAD to collect the nominals for each point it took, this is what I was taught anyhow. If I was scanning using touch trigger probing I would agree as the nominals would be generated from the CAD and the CMM would just drive to these nominals

          Boomer - I have noticed that Linear Open Scans always work so maybe I will just use this and hope Hexagon will get back to me with an answer, wont hold my breath though



          • #6
            One thing that I noticed. When a patch scan is created, if you select the CAD surfaces that it is to use for finding nominals and you replace the CAD data aftethe fact, PC-DMIS cannot find the nominals because the number value associated with that particular surface has changed. Now you know and I know that this is an issue, I believe WILCOX does/did becaue I believe (don't know for certain) that this was corrected in 4.0/4.1. Anyways recreate your scan without choosing surfaces and that may take care of your problem.

            Also, what about increasing your find nominals tolerance?

            Here is another one for you in, 4.0/4.1 you can go into the clip planes dialog box, and unchoose "two sided shading", at that point you will see all CAD features that are not properly vectored. After doing this a new option is provided to the programmer called EDIT>>CAD VECTOR. Box select the entire model and hit ok. This will "fix" any vectors that are improperly represented. This representation doen't really effect the normal type of operations, like a auto-vector point or auto-circle, but does have an affect on continous scan operations. See? I am good for something and so is 4.1.

            Now all you people can ask me how this all works and I'll tell you "I don't know, I just know it works". Read the help files in 4.1 (you have down loaded 4.1 right?).

            James Mannes


            • #7
              I always select the surfaces so will try without selecting them on Monday and let you know how I get on.



              Related Topics


              • Roberto
                Patch Scanning_Find Nom.
                by Roberto
                Hola amigos!!

                I don't do much scanning, so please give some help.

                I'm trying to add a patch scan on a curved surface right...
                11-03-2009, 02:49 PM
              • DrBudman
                by DrBudman
                When you insert a scan, on the scan dialog box you have a pull down menu with that has findnoms on the left side then on the right side there is a button...
                05-19-2006, 11:29 AM
              • womer
                by womer
                Here is the problem. I write a program off line then run program live after it is done I have to go and change the Nominal's back to match the Print....
                09-04-2014, 08:20 AM
              • mattias
                scanning Couldn't find nominals
                by mattias
                anybody knows how to fix this error? How to avoid this this problem
                " Could not Find Nominals for hit(s) Do you want to delete hits in this...
                05-06-2016, 12:15 PM
              • Jeff Hunt
                Scan in a DCC program
                by Jeff Hunt
                I have what is probobly a simple question. I am using PCDMIS 2010 & I have a program where I have written in section scans throught some areas of...
                07-09-2010, 10:15 AM