hexagon logo
Register Sign in
  • Replies 6 replies
  • Subscribers 223 subscribers
  • Views 80 views
  • Users 0 members are here
Options
Related

Readpoint in front of an iterative alignments?

METROLOGY_GUY76
Hello fellow Metrologist!
My question is going to be geared more to the Gurus here on PC DMIS forum; I have an aerospace part that has target points A1,A2,A3,B1,B2,C1 ....I know how to create an iterative alignment...however, what I usually do is make a readpoint in a location where I can do a small alignment, changing the location of the trighedron...However, the customer has supplied the CAD and wishes for us to keep the location were it is....its in a place you could not create a readpoint without going through the part.
How do i create a readpoint that goes directly into the iterative?
Thanks in advance.
Parents
  • Hi, If you select a feature from the CAD, I.e. a hole and note down the XYZ. Create your readpoint and origin it, then create an alignment and offset (normally negative) your XYZ so that your origin is back in the CAD alignment, then in theory you should then be able to start your alignment feature measurement. Note that it's only the XYZ affected with no rotation or level so would only really work with a 'flat, square' part.

    I can confirm that this method works. It can also work if you need to rotate the alignments - if the origin of the part is not in the same orientation as the part as it sits on the CMM.

    When doing this, I find it helpful to import a model of a cube into the model assembly and translate the corner of that cube to the origin of the part model. Also translate the rotations of the cube to match the part model. Then, there is reference point that can be selected to ensure that all of the alignments worked out properly in the end.

    Be sure to use nice big prehit and retract values on the iterative alignment hits to help find the part. All of this assumes that you have a good fixturing method that orients the part in a reliable manner.​
Reply
  • Hi, If you select a feature from the CAD, I.e. a hole and note down the XYZ. Create your readpoint and origin it, then create an alignment and offset (normally negative) your XYZ so that your origin is back in the CAD alignment, then in theory you should then be able to start your alignment feature measurement. Note that it's only the XYZ affected with no rotation or level so would only really work with a 'flat, square' part.

    I can confirm that this method works. It can also work if you need to rotate the alignments - if the origin of the part is not in the same orientation as the part as it sits on the CMM.

    When doing this, I find it helpful to import a model of a cube into the model assembly and translate the corner of that cube to the origin of the part model. Also translate the rotations of the cube to match the part model. Then, there is reference point that can be selected to ensure that all of the alignments worked out properly in the end.

    Be sure to use nice big prehit and retract values on the iterative alignment hits to help find the part. All of this assumes that you have a good fixturing method that orients the part in a reliable manner.​
Children
No Data
© 2024 Hexagon AB and/or its subsidiaries. Privacy Policy | Cloud Services Agreement