Jump to content

Problem keeping base alignments


---
 Share

Recommended Posts

I am having problems with an Eclipse we have keeping base alignments. We will run a program, then the next day, putting the part exactly on the table as the previous run, and it will be .100 to over an inch off. It is like it does not remember where the part is exactly. I will then have to do a manual alignment, then it will run fine for the day, sometimes more. It does not happen all the time, but is happening more frequently over the last couple of months. Any thoughts as to what may be going on. We are running 2023 with the latest patches installed. It also happened towards the end of when we were running 2020 before switching to 2023.
Link to comment
Share on other sites

Are you running current alignment when you switch between parts? If so you need to choose the program alignment which is the third option (under Current Alignment) and it will perform the alignment without manual.
Hope this help
Link to comment
Share on other sites

Not running current alignment. Always running the program alignment. It is definitely a head scratcher for us. Thanks though.
Link to comment
Share on other sites

Please sign in to view this quote.

Fixture is always in the same spot. We have an X Y grid plate on our tables and we locate the same every time.
Link to comment
Share on other sites

Are you using the (CNC) variant of the alignment?

The Non-CNC variant will always reference your manual run, the CNC one will reference the previous CNC run and there is the potential for that to become an issue without it being obvious.

In general it's safer to use the Non-CNC variant although obviously both have their correct use cases.
Link to comment
Share on other sites

Are you running CNC version of the base alignment? that one moves if the part is a little bit off. It moves with the part. Could explain why after a day its off by .100
Don't use the CNC version of the base alignment.

Is another program using the same base alignment with the same name? Its possible you have a different part that has a base alignment with the same name so when you run the other part, it moves a little bit when you come back to the first part.
Link to comment
Share on other sites

Please sign in to view this quote.

Thank you. We are not running the CNC version of the base alignment. There is no other program using the same alignment name as the programs in question. I am at a loss as to why this is happening. I thought there could be another machine with the same base alignment, but the parts are being run exclusively on this machine and not the other machines. The other machines do not have the same base alignment name in them, so it is strictly this machine having the issues.
Link to comment
Share on other sites

Please sign in to view this quote.

Even if other machines would have used the same base alignments, this could hardly be the issue since base alignments (the measured ones, not the definitions) are always stored locally on the CMM computer.

If the amount of shift would have been small, I would have suggested to check the reliability and repeatability of the machine zero. We had issues with this in the past because of drifting end switches. But that could never cause a shift in the range of an inch.
Link to comment
Share on other sites

Please sign in to view this quote.


I would suggest a mini gage R&R.
Load the part and run it 3 times without touching the part.
Its possible that the fixture is getting moved every time it runs. This will check for that.


Then run it another 3 times but take it out and load it back up every single time.
Its possible that every time you take out the part and the fixture and put it back on the machine, it is never on the same spot which causes it to move.

That way you can see if it not just the fixture itself that is giving you the issue.

If you get repeatable numbers after this, then we can safely say the fixture is not the issue.


Another thing that could be is the alignment. Maybe you're probing features that vary a lot per part so it moves and crashes when it checks certain parts.
Link to comment
Share on other sites

 Share

×
×
  • Create New...