False hits

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  • False hits

    Just checking to see if anyone has some insight on this issue. I have two "Global Image" machines. One is about 3 1/2 years old, the second is about 1 1/2 years old. The older of the two has been experiencing problems with taking hits while moving the probe downward and occasionaly upward as well. This problem seems to occur most often while in a A90 tip rotation.

    We have been having the problem for a long time now, but it seems to have gotten much worse in the last few weeks. Before, we could just slow down while doing anything manualy and it would be alright, but lately its becoming a real hinderance. In the past it only seemed to happen when manually moving the probe, but I suspect it is happening during DCC operation.

    We are getting the machines calibrated later this week and I wonder if it would be a mistake to calibrate before we get this thing figured out. Any suggestions would be greatly appreciated. Thanks.

    Aren
    Aren Winebrenner

  • #2
    You do not say which probe you are using or how long the tips are. Both greatly affect false hits. If you are using a tp2, there is a tension screw that may need slight adjustment. The recent increase in the problem could also be due to dirt. I presume you have cleaned often, but the calibration tech may be to do a better cleaning or made some adjustment to smooth out the z axis. HTH
    sigpic"Hated by Many, Loved by Few" _ A.B. - Stone brewery

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    • #3
      What size tip are you using and what type of module (if any)? It could be a number of things or even a combination of a number of things. I'd consider

      -Size of tip are you rotating a 6X50 or larger/longer?
      -Cleanliness of the drive system. Is there a lot of machine movement resonating through the machine?
      -Type of module. Medium force, standard force?
      -Operator astuteness. You say you get it a lot in manual mode, how smooth and deliberate are the operator's motions?

      This does not sound like the case because you say it is mainly with tip rotations but is your CMM near welding equipment? This too will create false hits.

      Craig
      <internet bumper sticker goes here>

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      • #4
        ANd if you are using a tp200 like me. Had any crashes lately? How much is the light flickering. as a Tp 200 starts to go south they take more false hits.
        sigpic

        B&S Global 544
        Using 3.7mr3


        Peace
        Greg


        Nothin left ta dew but :) :) :) !

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        • #5
          I know it is affected useing a tp20 with the length of your tips and size they get old and tired too. If useing a tp20 or tp200 try changeing the mods and see if that helps
          Tom
          sigpic
          if you had soap on a rope it would be tied to yer ankle

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          • #6
            We are using a TP200. Standard force. I try to clean at least once a week. Tip length doesn't seem to make a difference. We are using everything from a .5mm x 27mm --- 4 mm x 40 long tips. It doesn't seem to discriminate based upon length. Astuteness levels definitely vary by operator (3 of them), but it happens to me as well, even when moving deliberately, and slowly. Its unpredictable though.
            Aren Winebrenner

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            • #7
              We replaced the TP200 about 8 months ago as well. We had the original die, got a new one and the ball bearings for the module seat kept falling out, so we recieved yet another new one.
              Aren Winebrenner

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              • #8
                Originally posted by Arenw
                We are using a TP200. Standard force. I try to clean at least once a week. Tip length doesn't seem to make a difference. We are using everything from a .5mm x 27mm --- 4 mm x 40 long tips. It doesn't seem to discriminate based upon length. Astuteness levels definitely vary by operator (3 of them), but it happens to me as well, even when moving deliberately, and slowly. Its unpredictable though.
                As stated below, the module and/or probe are highly suspect. Also, how well isolated from external vibration is your machine? If there are other machines nearby shaking the floor, that will do it too. HTH.
                sigpic"Hated by Many, Loved by Few" _ A.B. - Stone brewery

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                • #9
                  Aren,
                  It sound like you may need your TP200 rebuilt. I have a global 9-12-8 and had to rebuild mine 2x's already. NO crashes either. I would like to ask you do you have any noise out of you X axis belts/gears up on top of your machine. I have had to have a gear and belt replaced once and now it is starting again. I think this is why I am having some of the problem I am having. BS is coming to look at my machine in a couple of weeks.
                  PCDmis 3.5mr2 CAD++

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                  • #10
                    Maybe I will switch the modules on the two machines I have and see if I have the problem on the other machine??? I guess that would be worth a shot.

                    There are a couple mills about 15 feet away, on the other side of the wall from where my machine is sitting, but we don't seem to have much noticable vibration-except when the guys have a crash(which happens more than we would like!)
                    Aren Winebrenner

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                    • #11
                      Originally posted by Arenw
                      Maybe I will switch the modules on the two machines I have and see if I have the problem on the other machine??? I guess that would be worth a shot.

                      There are a couple mills about 15 feet away, on the other side of the wall from where my machine is sitting, but we don't seem to have much noticable vibration-except when the guys have a crash(which happens more than we would like!)
                      You might also try switching the tp200s, after the module switch. It might help you identify either bad module, probe, or machine problem.
                      sigpic"Hated by Many, Loved by Few" _ A.B. - Stone brewery

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                      • #12
                        Originally posted by TRD_racing
                        Aren,
                        I would like to ask you do you have any noise out of you X axis belts/gears up on top of your machine.
                        I don't seem to hear anything that jumps out at me, but I may not be the best person for that job. Too many years of playing too loud and too long in nasty places have not been kind to my ears!
                        Aren Winebrenner

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                        • #13
                          The thing about your TP200 is that the probe is inside the TP200 unit itself unlike the TP20 which triggers through the module. The tech at Renishaw told me this. I have names and a number for Renishaw, they will check out you head if you like. I have done this 2 times. They haven't charged me for my TP200 the first time but the SP600 they charge me $90. That is how I found out that the belts and gears were bad, both my heads came back ok. This machine always had a noise up top so I thought it was normal because I had run different machines in the past. I had a BS saleman come in one day and told me that it didn't sound right.
                          PCDmis 3.5mr2 CAD++

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                          • #14
                            I don't seem to hear anything that jumps out at me, but I may not be the best person for that job. Too many years of playing too loud and too long in nasty places have not been kind to my ears!
                            You would be able to hear this. Now that I know it not right it sound loud now
                            PCDmis 3.5mr2 CAD++

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                            • #15
                              Well gentlemen, it's strange, but, I switched modules and now I can't get either machine to take false hits??? I'm perplexed. The only thing that I can think of is that maybe there was a bit of debris somewhere where the module screws into the PH10 and it was just enough to give me headaches.

                              I'm not sure how this will work out, but I REALLY appreciate all of your help and fast responses. You guys are great! Thanks a lot.

                              Aren
                              Aren Winebrenner

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