hexagon logo

Manual vs DCC alignment

I have taken the basic 1 week PCDMIS course from Hexagon.

Currently I have only modified part programs written by the programmer at our parent company location to run on our cmms.

I work with version 3.7 on cmm 2 and 2014 on cmm 3.

Cmm 1 has Measuremax which I am not sure how to program. This question is regarding cmm 2.

I think I may be a little confused about the purpose of running the dcc alignment after the manual alignment has run. I was under the impression that the manual alignment was to locate the part on the cmm, and the dcc alignment was the "fine tuning" and would adjust for very slight placement changes.

We have a fixture that is bolted to the fixture plate. The part is then mounted on the fixture and screwed into place using 1 screw. The part is secure, but due to different cavities with different die conditions may sit slightly different in the fixture each time. We are measuring the true position of a bore on the x minus side of the part with respect to the plane and bore at the x/y/z 0 position that is used to set the part alignment.

What we have noticed is that when we run the first part with the manual alignment the true position is within tolerance (.04mm). When we run a second part, if I mark all but choose not to mark the manual alignment portion, we see true position values between 0.1mm and 0.2mm.

If I then run the program on that same part again using the manual alignment without moving the part the true position values are again within tolerance. From what I read online yesterday after lots of digging it looks like the dcc alignment serves only to ensure the alignment features are properly probed and defined.

Is there any way around running the manual alignment each time? I don't mind if it's necessary for different cavities or runs, but for a 300pc cpk it's quite time consuming. Thanks in advance for any answers and/or suggestions. Oh, and I'm well aware of the noob hazing here. I have thick skin Slight smile.

Amber
Parents
  • Just a general note. I have never used manual alignments in 15+ years of programming.

    My suggestion is avoid the manual alignment. There is no good reason for the DCC alignment to give you poorer results. If this is the case then as stated above there is a difference in the alignments, or probe points. A DCC probing should always give you better results.

    I suggest using a READPOINT, and letting the machine do the rest. Inserting a pic of the probe at the start position, or readpoint, into your operator comment is easy and very helpful. I have just stepped into a situation where manual alignments with no pics, and then dcc alignments based from MCS are used in most, if not all the programs, and it is nothing short of a mess.

    I understand you may not be in a position to change the way programs are started, but if you can get that change made you'll be glad you did.
Reply
  • Just a general note. I have never used manual alignments in 15+ years of programming.

    My suggestion is avoid the manual alignment. There is no good reason for the DCC alignment to give you poorer results. If this is the case then as stated above there is a difference in the alignments, or probe points. A DCC probing should always give you better results.

    I suggest using a READPOINT, and letting the machine do the rest. Inserting a pic of the probe at the start position, or readpoint, into your operator comment is easy and very helpful. I have just stepped into a situation where manual alignments with no pics, and then dcc alignments based from MCS are used in most, if not all the programs, and it is nothing short of a mess.

    I understand you may not be in a position to change the way programs are started, but if you can get that change made you'll be glad you did.
Children
No Data