Trouble with Y direction even though alignment appears correct

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  • Trouble with Y direction even though alignment appears correct

    We have created a program and are having trouble with the Y direction. We created two planes and a circle and created an alignment. The trihedron looks correct on the CAD file. After the alignment, we measured several holes and they are consistently off in the Y direction. The X and Z directions appear to be correct. We tried several other alignments, all of which appeared correct on the CAD, but they show off in the Y direction as well. We are relatively new to programming so any assistance/guidance would be greatly appreciated.

  • #2
    please post code
    SF7107(PCD), SF454(PCD), 152614(Quindos), 9159(Quindos), 7107(Quindos), B&S Manual, M&M Gear Checker

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    • #3
      Originally posted by DAN_M View Post
      please post code
      ...especially the alignment features and the alignment.
      PC-DMIS CAD++ 2o19 R1 SP11

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      • #4
        Have you verified by other means the holes aren't off in the Y direction?

        Automettech - Automated Metrology Technology

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        • #5
          Startup =alignment/start,recall:use_part_setup,list=yes
          alignment/end
          mode/manual
          format/text,options, ,headings,symbols, ;nom,meas,outtol,dev,tol, ,
          loadprobe/6mm_ruby_probe
          loadprobe/6mm_ruby_probe
          tip/tip1, shankijk=0, 0, 1, angle=0
          pln1 =feat/contact/plane/default,cartesian,none
          theo/<-17.954,69.86,-60.311>,<0,0,-1>
          actl/<29.129,-24.832,-1.694>,<0.1317461,-0.0811515,-0.9879562>
          targ/<-17.954,69.86,-60.311>,<0,0,-1>
          angle vec=<-1,0,0>,square
          show feature parameters=no
          show contact parameters=yes
          numhits=2,numrows=2
          spacer=0
          show hits=no
          pln2 =feat/contact/plane/default,cartesian,none
          theo/<-49.81,50.189,-55.309>,<0,-1,0>
          actl/<31.158,-19.714,4.271>,<-0.8680485,0.4964632,0.0040086>
          targ/<-49.81,50.189,-55.309>,<0,-1,0>
          angle vec=<1,0,0>,square
          show feature parameters=no
          show contact parameters=yes
          numhits=2,numrows=2
          spacer=0
          show hits=no
          workplane/zplus
          cir1 =feat/contact/circle/default,cartesian,in,least_sqr
          theo/<-39.67,50.189,-55.055>,<0,-1,0>,7.5
          actl/<29.882,-21.891,3.515>,<-0.8679139,0.4966968,0.0042072>,7.513
          targ/<-39.67,50.189,-55.055>,<0,-1,0>
          start ang=0,end ang=360
          angle vec=<1,0,0>
          direction=ccw
          show feature parameters=no
          show contact parameters=yes
          numhits=4,depth=0.3,pitch=0
          sample method=sample_hits
          sample hits=3,spacer=0
          find hole=disabled,onerror=no,read pos=no
          show hits=no
          a1 =alignment/start,recall:startup,list=yes
          alignment/level,zminus,pln1
          alignment/rotate,yminus,to,pln2,about,zminus
          alignment/trans,xaxis,cir1
          alignment/trans,yaxis,pln2
          alignment/trans,zaxis,pln1
          alignment/end

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          • #6
            The angle between your two planes is 90 degrees THEO (perpendicular), but 181.865 ACTL (almost parallel). No wonder you get funky results when rotating to the second plane...
            AndersI
            SW support - Hexagon Metrology Nordic AB

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            • NinjaBadger
              NinjaBadger commented
              Editing a comment
              I don't see that?

              Plane1 vector = 0.1317461,-0.0811515,-0.9879562

              Plane 2 vector = -0.8680485,0.4964632,0.0040086 (pointing more in XMINUS than YMINUS)

              There's quite a difference between plane 2 theoretical vector and actual but that shouldn't matter too much.

            • Douglas
              Douglas commented
              Editing a comment
              30° would be .86603 and 0.5000 for the vector so it is off by very close to 30° which is probably what the nominal should be... gonna need a drawing to know more

            • AndersI
              AndersI commented
              Editing a comment
              Sorry - I was too quick, and made the usual error of not setting the correct workplane before dimensioning "angle between"...

          • #7
            those circles are drill holes on the face pln2...?

            Change the holes to use sample hits on pln2 and add a depth to probe at. This puts measured hole location where the hole intersects the face, what you have now is a measured hole location at the center of the probed points... at some depth within the hole. That depth you are probing at multiplied by the sine of 30° is probably about what your error is in the Y... still totally guessing with no drawing though
            Last edited by Douglas; 01-08-2020, 02:47 PM.

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            • #8
              What would you recommend be done to correct the issue?

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              • Douglas
                Douglas commented
                Editing a comment
                1) change the workplane to 'pln2' where you have zplus for the circles.
                2) add sample hits, take them on pln2
                3) enter the depth to probe the hole in the depth field, how far in from the face

                This puts hole position where the cylinder intersects the face.

                or

                1) probe these holes as cylinders
                2) construct a point at the intersection of that cylinder and the face

                the constructed point will be your hole location on the face by either of these methods, using cylinders will eliminate the need for workplane concerns though

              • Douglas
                Douglas commented
                Editing a comment
                before all that correct the THEO IJK values in the pln2 and circle features... it would probably run and give you a result with the incorrect vectors using sample hits but best to make them proper

            • #9
              436801.pdf

              Attached is drawing. We are able to run older programs we have made and don't seem to have any issue. We have calibrated the machine and tips and everything is measuring properly. We took an older program that we have no problem running and saved it as a new program. We deleted everything past the alignment and then added the holes for this new part and it was still showing off in the Y direction. We have sample hits on the hole on plane 2. The hole is Datum C. Thanks for the help as this really has us scratching our head.

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              • #10
                looks like that angled face is the one... by your measured result it is at an angle of 30° from the top plane...? IJK 0,0,1 is straight up like the top face and is correct in pln1.

                if that face is indeed at 30° then THEO vectors IJK for should be -0.86603,0,0,500 for both that face and the holes on it, change that first

                I'm assuming by measured vectors that the part is sitting on your table like that bottom right view on the drawing

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