True position issues with round slot

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • True position issues with round slot

    Good morning everybody.

    I'm trying to figure out why pc dmis is not using the MMC bonus tolerance on Round slots.
    Does anyone knows why? may be I'm doing something wrong.
    See attached pictures to meet requirements and part of the report,
    Attached Files

  • #2
    You may have to create a generic feature (circle) that uses the LF value as diameter/measured diameter and use the generic circle for position evaluation.
    You will need one circle for WF and another for LF.

    Look at the related topics below here, this has been covered several times already and you should be able to find more information in these threads.
    PC-DMIS CAD++ 2o19 R1 SP10

    Comment


    • #3
      Looking at your print, I do not call the FCF's TP. One FCF notes one direction, the other notes the other direction. There is no diametrical callout in the FCF, so my opinion is your tolerance will be ± .05 for both. Can anyone else confirm this?

      Comment


      • #4
        Of course it's a TP, it's even two of them - but you must set the Planar zone correctly so PC-DMIS knows which direction should be checked. But it seems PC-DMIS will only use the smaller of the WF and LF bonuses, so you may still need to do as vpt.se says if you want to use the larger bonus in one direction.
        AndersI
        SW support - Hexagon Metrology Nordic AB

        Comment


        • #5
          have you ever used the constructed with tool ??? that's how i would dimension TP for a feature like this measure with 2 half circles (make sure you use an odd number of points and make sure your circles are 180 deg and you with width you should be a ble to do what the print is asking

          Comment


          • #6
            TP is the perfect center of the feature as far as I understand. PCDMIS only TP the diameter size, such as a hole or width of a slot. If a slot can be diametrically toleranced in width and length to the standard, then the powers at PCDMIS should develop the software to calculate out the location as per the standard. There should be no doing it this way or that way. If you can click a circle feature and get all the TP info, then a slot should be done the same way, click it and report. So I am asking the power that oversees this forum, "why can't PCDMIS TP a slot with one click like it can a hole?" Simple answer please.

            Comment


            • #7
              well a slot is more like a line with a defined length and if you look at the print the slot TP in x has its own call out and so dose Y location have its own call out its not a diametric TP.

              Comment


              • oddam
                oddam commented
                Editing a comment
                I agree with your statement, which is why I mentioned earlier, each axis should get only a ± .05 tolerance. I have seen programmers TP the width and TP the length separately, saying this is correct. My question to them is, which reading is correct, the width or the length? The TP formula takes into account both location axis. Would the axis reading introduce possible error? I knew a programmer that actually took both readings, width and length and calculated the TP of the slot from the them. He said the minor axis would be minimal in error, not sure, I am not a math guru. I was always told the width of a slot is the primary concern for location, the length gives that movement to locate if needed.

              • Matthew D. Hoedeman
                Matthew D. Hoedeman commented
                Editing a comment
                IF you do NOT have PERP-TO-CL marked, Pcdmis ONLY uses the axis used in the dimension for calculating position.

            • #8
              if the slot only had 1 TP call out then yes that would be right but since this slot has 2 call out each TP call out really only use the axis its controlling are you using xact measure?? if so you will see on your report that your true position target frame is a square and not a circle so one call out controls up and down and the other controls left to right so basically what ever your off from nominal you just double it and that's your TP in that axis, and you dont need to do the generic feature circle trick because they are each controlled by its own call out.

              Comment


              • #9
                Assuming that Datum A constrains the plane which the slot goes through, as I understand it, that would give an implied perpendicularity call out to the thru hole (again, assuming it IS a thru hole, as I see no depth call out). Also assuming that Datum B constrains the X dimensions and C constrains the Y, then the Relation of WF to C is immaterial, as there's no callout there. Given a perfect location in one dimension allows for 1/2 of the given GD&T tolerance in the opposing datum's dimension. Concurrently, the Relation of LF to B is immaterial, as there is no callout there as well, and only 1/2 the GD&T tolerance for C applies.

                Therefore, before bonuses for MMC, I would agree with the .005 tolerance in both dimensions.

                If I see the issue incorrectly, and I may, I believe it's prudent to err on the side of caution, and hold to a tighter tolerance, which in this case I would be.

                Of course, programming the CMM to give you that report may be another matter all together. I've got a couple TP calculators that I like, and generate reports with them as necessary.
                Last edited by Quality ish; 05-28-2019, 11:04 PM.

                Comment


                • #10
                  Originally posted by vpt.se View Post
                  You may have to create a generic feature (circle) that uses the LF value as diameter/measured diameter and use the generic circle for position evaluation.
                  You will need one circle for WF and another for LF.

                  Look at the related topics below here, this has been covered several times already and you should be able to find more information in these threads.
                  I did it but is a pain in the *** because are a lot of slots to report

                  Comment


                  • #11
                    Thanks a lot guys you are correct and as much I can see there's no a default way in pc dmis to report as the drawing calls.
                    I appreciate your answers.
                    You are the best.

                    Comment


                    • #12
                      This is the method that I use. (see attached image)
                      Attached Files

                      Comment


                      • Mike Ruff
                        Mike Ruff commented
                        Editing a comment
                        Shouldn't the LF be checking the Y-location? The bonus of a slot width/length only applies along the axis it will affect

                    • #13
                      A tip is to use pointers/referencing the nominals as well as the actuals. This way you won't have to change the generic circle the day the slot nominals change.

                      Code:
                      NOM/XYZ, <SLOT1.TX, SLOT1.TY, SLOT1.TZ>
                      Also, for rounded slots you can use the LENGTH and DIAM properties for the length and the width.
                      PC-DMIS CAD++ 2o19 R1 SP10

                      Comment


                      • #14
                        I'm using 2019R2; I have tried to TP the length of the slots but not getting any 'bonus' value for the variation in size.

                        Code:
                        SLTR1        =FEAT/CONTACT/ROUND SLOT/DEFAULT,CARTESIAN,IN
                                      THEO/<16.101628,4.000037,0>,<0,0,1>,<0,-1,0>,0.205,0.305
                                      ACTL/<16.110837,4.027289,-0.071034>,<-0.0039757,-0.0003417,0.999992>,<0.010797,-0.9999417,-0.0002988>,0.203561,0.299239
                                      TARG/<16.101628,4.000037,0>,<0,0,1>,<0,-1,0>
                                      MEAS ANGLE=150
                                      SHOW FEATURE PARAMETERS=NO
                                      SHOW CONTACT PARAMETERS=NO
                        SLT1_W       =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,IN,$
                                      NOM/XYZ,<SLTR1.TX,SLTR1.TY,SLTR1.TZ>,$
                                      MEAS/XYZ,<SLTR1.X,SLTR1.Y,SLTR1.Z>,$
                                      NOM/IJK,<0,0,1>,$
                                      MEAS/IJK,<0,0,1>,$
                                      DIAMETER/0.205,SLTR1.D
                        SLT1_L       =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,IN,$
                                      NOM/XYZ,<SLTR1.TX,SLTR1.TY,SLTR1.TZ>,$
                                      MEAS/XYZ,<SLTR1.X,SLTR1.Y,SLTR1.Z>,$
                                      NOM/IJK,<0,0,1>,$
                                      MEAS/IJK,<0,0,1>,$
                                      DIAMETER/0.305,SLTR1.L
                        
                        SLTR2        =FEAT/CONTACT/ROUND SLOT/DEFAULT,CARTESIAN,IN
                                      THEO/<13.748867,6.740778,0>,<0,0,1>,<0,-1,0>,0.205,0.305
                                      ACTL/<13.751486,6.761948,-0.029351>,<0.0063702,-0.0265497,0.9996272>,<0.0130732,-0.9995598,-0.0266312>,0.200652,0.300986
                                      TARG/<13.748867,6.740778,0>,<0,0,1>,<0,-1,0>
                                      MEAS ANGLE=150
                                      SHOW FEATURE PARAMETERS=NO
                                      SHOW CONTACT PARAMETERS=NO
                        SLT2_W       =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,IN,$
                                      NOM/XYZ,<SLTR2.TX,SLTR2.TY,SLTR2.TZ>,$
                                      MEAS/XYZ,<SLTR2.X,SLTR2.Y,SLTR2.Z>,$
                                      NOM/IJK,<0,0,1>,$
                                      MEAS/IJK,<0,0,1>,$
                                      DIAMETER/0.205,SLTR2.D
                        SLT2_L       =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,IN,$
                                      NOM/XYZ,<SLTR2.TX,SLTR2.TY,SLTR2.TZ>,$
                                      MEAS/XYZ,<SLTR2.X,SLTR2.Y,SLTR2.Z>,$
                                      NOM/IJK,<0,0,1>,$
                                      MEAS/IJK,<0,0,1>,$
                                      DIAMETER/0.305,SLTR2.L
                        
                        SLTR3        =FEAT/CONTACT/ROUND SLOT/DEFAULT,CARTESIAN,IN
                                      THEO/<18.44206,7.52316,0>,<0,0,1>,<0,1,0>,0.205,0.305
                                      ACTL/<18.441513,7.556696,-0.026147>,<0.0017901,-0.0119928,0.9999265>,<-0.005764,0.9999113,0.0120029>,0.201364,0.30085
                                      TARG/<18.44206,7.52316,0>,<0,0,1>,<0,1,0>
                                      MEAS ANGLE=150
                                      SHOW FEATURE PARAMETERS=NO
                                      SHOW CONTACT PARAMETERS=NO
                        SLT3_W       =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,IN,$
                                      NOM/XYZ,<SLTR3.TX,SLTR3.TY,SLTR3.TZ>,$
                                      MEAS/XYZ,<SLTR3.X,SLTR3.Y,SLTR3.Z>,$
                                      NOM/IJK,<0,0,1>,$
                                      MEAS/IJK,<0,0,1>,$
                                      DIAMETER/0.205,SLTR3.D
                        SLT3_L       =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,IN,$
                                      NOM/XYZ,<SLTR3.TX,SLTR3.TY,SLTR3.TZ>,$
                                      MEAS/XYZ,<SLTR3.X,SLTR3.Y,SLTR3.Z>,$
                                      NOM/IJK,<0,0,1>,$
                                      MEAS/IJK,<0,0,1>,$
                                      DIAMETER/0.305,SLTR3.L
                        Last edited by brian.freeman; 01-03-2020, 08:09 AM.

                        Comment


                        • RanDawgg
                          RanDawgg commented
                          Editing a comment
                          If you are just finding the TP of the length of the slot, you probably have to specify the planar zone to just y or x within the position characteristic. It really depends on how the drawing calls it out. Is there a ø symbol in the TP callout? Is there a separate TP callout for the length and width?

                        • brian.freeman
                          brian.freeman commented
                          Editing a comment
                          Tried in both planar zones and still no 'bonus' in the length segment. But width segment there is bonus.

                      • #15

                        Still not bonus in length, but there is bonus in width.
                        Last edited by brian.freeman; 01-03-2020, 08:10 AM.

                        Comment


                        • KIRBSTER269
                          KIRBSTER269 commented
                          Editing a comment
                          C2_11 =FEAT/CONTACT/CIRCLE/ADAPTIVE_CIRCLE_SCAN,CARTESIAN,IN,LEAST_SQR
                          THEO/<-5.6415,-9.741,0.459>,<0,0,1>,0.188
                          ACTL/<-5.6402,-9.7392,0.459>,<0,0,1>,0.1878
                          TARG/<-5.6415,-9.741,0.459>,<0,0,1>
                          START ANG=270,END ANG=450
                          ANGLE VEC=<1,0,0>
                          DIRECTION=CCW
                          SHOW FEATURE PARAMETERS=NO
                          SHOW CONTACT PARAMETERS=NO
                          C2_12 =FEAT/CONTACT/CIRCLE/ADAPTIVE_CIRCLE_SCAN,CARTESIAN,IN,LEAST_SQR
                          THEO/<-5.6785,-9.741,0.459>,<0,0,1>,0.188
                          ACTL/<-5.6764,-9.7395,0.459>,<0,0,1>,0.1881
                          TARG/<-5.6785,-9.741,0.459>,<0,0,1>
                          START ANG=90,END ANG=270
                          ANGLE VEC=<1,0,0>
                          DIRECTION=CCW
                          SHOW FEATURE PARAMETERS=NO
                          SHOW CONTACT PARAMETERS=NO
                          POINT1 =FEAT/POINT,CARTESIAN,NO
                          THEO/<-5.6415,-9.741,0.459>,<0,0,1>
                          ACTL/<-5.6402,-9.7392,0.459>,<0,0,1>
                          CONSTR/POINT,CAST,C2_11
                          POINT2 =FEAT/POINT,CARTESIAN,NO
                          THEO/<-5.6785,-9.741,0.459>,<0,0,1>
                          ACTL/<-5.6764,-9.7395,0.459>,<0,0,1>
                          CONSTR/POINT,CAST,C2_12
                          PNT0 =FEAT/POINT,CARTESIAN,NO
                          THEO/<-5.66,-9.741,0.459>,<0,0,1>
                          ACTL/<-5.6583,-9.7393,0.459>,<0,0,1>
                          CONSTR/POINT,MID,POINT1,POINT2
                          DIM DIST5= 2D DISTANCE FROM CIRCLE C2_11 TO CIRCLE C2_12 PAR TO XAXIS,ADD_RADIUS UNITS=IN,$
                          GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
                          AX NOMINAL +TOL -TOL MEAS DEV OUTTOL MAX MIN
                          M 0.2250 0.0020 0.0020 0.2242 -0.0008 0.0000 0.2242 0.2242 -----#------------
                          F13 =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,OUT,$
                          NOM/XYZ,<-5.66,-9.741,0.459>,$
                          MEAS/XYZ,<PNT0.X,PNT0.Y,PNT0.Z>,$
                          NOM/IJK,<0,0,1>,$
                          MEAS/IJK,<0,0,1>,$
                          DIAMETER/0.225,DIST5.MEAS
                          DATDEF/FEATURE=DATUM_B1,B1
                          DATDEF/FEATURE=DATUM_C1,C1
                          DATDEF/FEATURE=DATUM_A1,A1
                          FCFLOC6 =POSITION : F13
                          FEATCTRLFRAME/SHOWNOMS=NO,SHOWPARAMS=NO,SHOWEXPANDED=NO,
                          SIZE TOLERANCES/1DIAMETER,0.225,0.005,0.005
                          PRIMARY DIMENSION/POSITION,<D>,0.007,MMC,A,B,C
                          NOTE/FCFLOC6
                          FEATURES/F13,,

                          Make generic circle like you would the other way, except when you report position take away the diameter symbol and report the correct direction, slots don't play well with position

                        • brian.freeman
                          brian.freeman commented
                          Editing a comment
                          @KIRBSTER269
                          Doesn't have diameter symbol in it (FCF). But will try with distance.
                          Tried separating (making generic circles) the width and length, no help.
                          Maybe this will (distance).
                          Thanks

                      Related Topics

                      Collapse

                      Working...
                      X