Problem with probe contacting parts.

[Simon.Duncan]

Hi Guys,

I am new to CMM programming and I am having a little trouble at work with parts we are getting from the line to measure. I was given a 'perfect part' to measure and have this set as a base reference for all the other parts I measure, which is all fine and dandy until we are getting parts massively out of specification and when I am running the program with these certain parts been bent more pc-dmis is telling the probe to go further down to measure the vector point but the part is bent upward and the probe comes in contact with it but instead of getting a reading it is giving me an error message as if the arm has crashed into something. I can hit f9 and change the point location by 0.1 and it runs fine but then this sticks to the report and does not specify how far the part is truly out. Is there A setting in parameters I can change ? maybe a range of hitting distance ? I have checked but could not see anything.

Thanks.

[BKulpa]

Under F10 adjust your prehit and retract distances slightly.

[NinjaBadger]

There are many solutions.

What BKulpa suggest will work, but will slow your program down (unless you adjust the prehit/retract just for certain parts in your program).

Instead of changing the THEO value for the vector point, you change the target instead (THEO is what the MEAS will be compared to for reporting purposes, the TARGET tells the CMM where to take the point.

Obviously if your parts bend one way and the other this isn't very good.


The other thing you can do is to control measurements relative to other features, so you could take a hit at the base of a bore, and use that hit to control where the hits in the bore occur.

[ALousyUser]

When I write the prehit/retract code after the first alignment, they're applied to the rest of the report. How do I stop the two commands from executing for some features?

[LostL]

I use relative measurement for parts like that.

[gibsonridge]

in addition to the prehit & retract adjusting the search distance (check distance) can also be helpful