Can excessive temperature damage machines?

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  • Can excessive temperature damage machines?

    Our lab is currently 86 deg F. I know our measurements at this point arent worth a dime but that does not seem to matter to management "Keep Running". So my question is: Can excessive temperatures actually damage a machine like cause air bearings to swell or something along those lines. I have 4 global images & i know there are many different materials on this machine each having there own thermal coefficient????

  • #2
    Originally posted by spazus_maximus View Post
    Our lab is currently 86 deg F. I know our measurements at this point arent worth a dime but that does not seem to matter to management "Keep Running". So my question is: Can excessive temperatures actually damage a machine like cause air bearings to swell or something along those lines. I have 4 global images & i know there are many different materials on this machine each having there own thermal coefficient????
    WOW!!!!
    I don't know if you can get damge (others might know). But, I had to remark because it appears you have 4 CMMs but Mgt won't cough up the jack to control the climate? WTF!!!???
    Bill Jarrells
    A lie can travel half way around the world while the truth is putting on its shoes. - Mark Twain

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    • #3
      I run 4 CMMs on the shop floor in heat anywhere up to around 90º 24/7. So far so good. Have been running non-stop for about 6 years now. We measure parts right off the machine. I can not afford to take a part in the lab and let it sit half a day to soak at ambient temperature.
      <internet bumper sticker goes here>

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      • #4
        Good question....the biggest thing I would think is the humidity with high humidity & temp the machine will for lack of a better word start sweating & you will have to wipe it down or the bearings will seize & other things will rust

        Had an old starrett years ago & we would have to wipe it down each morning.
        sigpic.....Its called golf because all the other 4 letter words were taken

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        • #5
          Originally posted by spazus_maximus View Post
          Our lab is currently 86 deg F. I know our measurements at this point arent worth a dime but that does not seem to matter to management "Keep Running". So my question is: Can excessive temperatures actually damage a machine like cause air bearings to swell or something along those lines. I have 4 global images & i know there are many different materials on this machine each having there own thermal coefficient????
          Good point. There is something called: temperature related backlash. Which means that after a large temperature swing, the mechanical structure does not quite get back to its original shape. So eventhough your machine may be perfectly functional at 86 and back at 68, it may be that you lost sqaureness without knowing it.

          At the very least, you ought to run planar diagonal ball bars or a machine checking gauge (from Renishaw) to verify whether your machine is still square. If it is, you're probably good to go. But don't be surprised if you see some of the axes to be out of sqaure and then you will need to re-calibrate the machine.

          My gut feel is that 86 is not too bad. But it is certainly borderline.


          Jan.
          ***************************
          PC-DMIS/NC 2010MR3; 15 December 2010; running on 18 machine tools.
          Romer Infinite; PC-DMIS 2010 MR3; 15 December 2010.

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          • #6
            Thanks for the replies. They finally got the air back on but we are going to implement a shut down procedure for temps above 85. This will include using the machine checking gage for squareness verification as Jan suggested.

            Well gotta go wipe the sweat off the machines....Man its miserable in here!

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            • #7
              Never heard of temp doing any damage. Same as craiger, had machines out in 100 degree temps. Only real damage Hot Temps have is on Attitudes.
              sigpicSummer Time. Gotta Love it!

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              • #8
                Originally posted by craiger_ny View Post
                I run 4 CMMs on the shop floor in heat anywhere up to around 90º 24/7. So far so good. Have been running non-stop for about 6 years now. We measure parts right off the machine. I can not afford to take a part in the lab and let it sit half a day to soak at ambient temperature.
                WOW!! The main reason I started doing this 16 years ago was for the air conditioning. I'd have to seek employment elsewhere under those conditions!!
                Bill Jarrells
                A lie can travel half way around the world while the truth is putting on its shoes. - Mark Twain

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                • #9
                  Originally posted by Paul Sarrach View Post
                  Never heard of temp doing any damage. Same as craiger, had machines out in 100 degree temps. Only real damage Hot Temps have is on Attitudes.
                  Not true. Damage can be as much as 10 to 20 arcsec's, depending on how high the excursion was.

                  However, it also depends a lot on the mechancial design of the machine. Some machines are really bad at this because of the way the vendor bolts the dissimilar materials together. I have worked on machines that would change squareness at a rate of 10 arcsecs' per 10 degrees. Awful!

                  Now, if you have a machine at 90, you calibrate it there and you leave it at 90, I agree with Craiger, no real problem. But if you have a machine at 68 and it goes to 90 for an extended (like overnight) period of time and you come back, ALWAYS check your sqaureness because that will go out first.


                  Jan.
                  ***************************
                  PC-DMIS/NC 2010MR3; 15 December 2010; running on 18 machine tools.
                  Romer Infinite; PC-DMIS 2010 MR3; 15 December 2010.

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                  • #10
                    Good point WingMan....The problem is there doesnt seem to be as many cmm programmer jobs as there were say 2 years ago. What the heck happened?

                    Jan your a sharp cookie. I am glad you dont work here I would be fired instantly

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                    • #11
                      Originally posted by spazus_maximus View Post
                      Good point WingMan....The problem is there doesnt seem to be as many cmm programmer jobs as there were say 2 years ago. What the heck happened?

                      Jan your a sharp cookie. I am glad you dont work here I would be fired instantly
                      I personally blame PC DMIS for that with it's "So easy a Cave Man could do it" looking interface. There are an awful LOT of PC DMIS 'Programmers' out there. Whether they ALL actually know what they are doing is a matter for debate - but it doesn't matter as long as they can make the machine move around the parts , go beep, and spit out a report, right? On top of that, the trend is going toward the CAD guys picking what they want measured and the software automatically generating the code to inspect it. Just hope the trade holds out for another 15 years!!

                      Luckily, even here in the Rust Belt Capital of Ohio there are still plenty of CMM Jobs to be had.
                      Bill Jarrells
                      A lie can travel half way around the world while the truth is putting on its shoes. - Mark Twain

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                      • #12
                        More stuff to consider...

                        Jan seems to have the warpage/out of square side of things covered so I won't talk about it.

                        I would guess that depending on your machine's construction there are other things that could happen. We also need to look at two conditions:

                        1) Temperature is high or low but relatively steady
                        2) Temperature fluctuates constantly

                        I would think that at a high stable temp, the only thing (aside from warpage/out of square) you would need to worry about is shorter life span from things like motors and belts and electronics. All of those are probably insignificant.

                        If the temp. is constantly changing I think that I'd worry more. Aside from the warpage/out of square, when you change the temp, things made of different materials have to flex/stretch/compress in order to stay bolted together. The greater the temp swing, the more flex/stretch/compress the parts are subjected to. It would seem that things could very easily become loose or suffer fatigue failures if the temp is constantly changing.

                        Also, consider the machine and parts. We all know that the parts should 'soak' in the lab to get up or down to the lab's temp. Now, what if the lab temp goes way up (to 86º)? Well, if they fix the air, and at that time you bring in some 6" square parts and set them on a table to 'soak'. Tomorrow the air temp is back to 68º - you figure those 6" square parts are at the air temp. Maybe not so with that 1 ton chunk of granite that your machine is based on. Sure, the bridge and other thin metal parts may be back to 68º pretty quick but the granite is going to take a lot longer. In that case, your x and z values (scale attached to metal bridge/ram) might be back to normal but your y values (scale attached to granite) might still be 'stretched'.

                        Simply because of its 'thermal mass' your machine is probably going to take a lot longer to stabilize at one temp. and be back to 'normal'

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                        • #13
                          Originally posted by Jan d. View Post
                          Not true. Damage can be as much as 10 to 20 arcsec's, depending on how high the excursion was.

                          However, it also depends a lot on the mechancial design of the machine. Some machines are really bad at this because of the way the vendor bolts the dissimilar materials together. I have worked on machines that would change squareness at a rate of 10 arcsecs' per 10 degrees. Awful!

                          Now, if you have a machine at 90, you calibrate it there and you leave it at 90, I agree with Craiger, no real problem. But if you have a machine at 68 and it goes to 90 for an extended (like overnight) period of time and you come back, ALWAYS check your sqaureness because that will go out first.
                          Jan.
                          The CMM's I have used and seen that are on shop floors and are working in extreme conditions have all been checking to tolerances where that type of change is accecptabe. I would not check anything with a tight tolerance under those conditions nor with those CMM's
                          sigpicSummer Time. Gotta Love it!

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                          • #14
                            Originally posted by Wingman View Post
                            I personally blame PC DMIS for that with it's "So easy a Cave Man could do it" looking interface. ...... Just hope the trade holds out for another 15 years!!

                            I can not believe cmm programmers will be needed in ten years. Technology moves entirely too fast. Look the advances in metrology over the last ten years..............

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                            • #15
                              Jobs may become fewer, but we will still be needed. I have maybe 13 years to go.
                              sigpic


                              Was
                              Pc-dmis 3.5 MR1 B & S 2009 MR1

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                              2010 MR3

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