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compensating for a vise when tramming

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  • compensating for a vise when tramming

    I have a Series I Bridgport and I need to tram the head. I think I remember reading once that Bridgeport recommends that the -Y postion should be .001 (?) high to compensate for the table deflection caused by the weight of a mill vise. In my case the vise is a Kurt D-688 and weighs about 75#. Is anyone familiar with this?

    Darren Delzell

  • #2
    tram it to your vise

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    • #3
      Might that also be a reason to consider the "E-Z Tram" or shop made equivalent tramming fixture that can straddle the vise?
      Cheers,

      Frank Ford
      HomeShopTech

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      • #4
        you want to compensate for your knee lock too.

        or tram the head for non use of knee lock ..or for use of knee lock

        or compromise .

        all the best.mark

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        • #5
          Originally posted by mochinist
          tram it to your vise
          I considered this and it is probably the best option as the Kurt has a nice flat machined area.

          As to the other replies:

          I am aware that I need to be consistent with the knee lock/unloked contition.

          Unless I am not understanding (possible) I don't think an "EZ tram" or equvilent would be practical with a vise because the vise covers up all of the "y" axis area on the table.

          I appreciate the fast responses as I am off today and wanted to get this done.


          Carbmaker
          Cyclone Carb LLC

          Darren Delzell

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          • #6
            Tram it to the table and pray the table is parallel to the ways. The head should be parallel to the axis of travel, not some random surface up above it.

            Load the vice. If the vice is off, shim it up. Or grind the vice to make the top surface parallel to the bottom.

            A trick guys at work taught me to use is to make up a ton of mild steel soft jaws for our vices. We stick them on the vice, clamp down on some scrap, and mill a step into the top of the vice jaw. This little step is now pretty much dead to rights parallel to the axis of travel regardless of the table or vice condition, and is more convenient than using parallels and some sort of parallel keeper. The guys who do this never have an issue maintaining very close tolerances on parallelism or perpendicularity in any direction.

            Most stuff that's +/- .005" won't care how you tram the vice as long as it's somewhere in the ballpark. But if you have to do any closer work or have geometry that must be preserved, tramming differently can cause you inexplicable errors and headache trying to figure out what's wrong.

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            • #7
              The bed of the vise isnt just some random surface, regardless either way will work, there is more than one way to do things. Personally I like to use parallels so I can remove them if I am milling or drilling real close to the edge of the part that meets the jaw.

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              • #8
                It is a random surface. It doesn't dictate the motion of the machine in any way, and is one more error stacked on top of the table, which already isn't parallel with the ways. It's just close. There's no inherent physical property or phenomenon that aligns the vice surface (or the table surface, for that matter) with the ways.

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                • #9
                  Unless I am not understanding (possible) I don't think an "EZ tram" or equvilent would be practical with a vise because the vise covers up all of the "y" axis area on the table.
                  Actually, the E-Z Tram is designed specifically to work over the vise. I got one a couple of years ago and it has improved my tramming experience because it allows the indicator to swing in a very wide arc.
                  Cheers,

                  Frank Ford
                  HomeShopTech

                  Comment


                  • #10
                    If you are working on the vise,tram off the vise.If you are working on the table tram off the table.If you are working on an angle plate,tram off the angle plate.

                    Since it's a B-port you will be tramming often so better get used to it.Just a fact of life I am here to say.
                    I just need one more tool,just one!

                    Comment


                    • #11
                      Neat trick

                      Originally posted by toastydeath
                      Tram it to the table and pray the table is parallel to the ways. The head should be parallel to the axis of travel, not some random surface up above it.

                      Load the vice. If the vice is off, shim it up. Or grind the vice to make the top surface parallel to the bottom.

                      A trick guys at work taught me to use is to make up a ton of mild steel soft jaws for our vices. We stick them on the vice, clamp down on some scrap, and mill a step into the top of the vice jaw. This little step is now pretty much dead to rights parallel to the axis of travel regardless of the table or vice condition, and is more convenient than using parallels and some sort of parallel keeper. The guys who do this never have an issue maintaining very close tolerances on parallelism or perpendicularity in any direction.

                      Most stuff that's +/- .005" won't care how you tram the vice as long as it's somewhere in the ballpark. But if you have to do any closer work or have geometry that must be preserved, tramming differently can cause you inexplicable errors and headache trying to figure out what's wrong.
                      That's a neat trick that will do me just fine for the stuff I do. Thanks for sharing that.
                      "When it comes to paradigms ... shifts happen" - Alain Rossman

                      Comment


                      • #12
                        Originally posted by wierdscience
                        If you are working on the vise,tram off the vise.If you are working on the table tram off the table.If you are working on an angle plate,tram off the angle plate.

                        Since it's a B-port you will be tramming often so better get used to it.Just a fact of life I am here to say.
                        Know here is some one who know`s what he is talking about. I have been in front of Bridge ports for 30 years . Tram the table then check every thing else. If your vise is not flat make it flat .if angle plate no square make it square. if it takes more than 5 minutes to tram head in you taking to long.Dont try to do it cranking on the worm bolts get it close snug the binding bolts and tap the head around with the palm of your hand up high on the pulley housing.1/2 thousand is close enough.Unless you trying to do jigbore work. And be ready to do it again after heavy cutting . some times 5are6 times a day.
                        Every Mans Work Is A Portrait of Him Self
                        http://sites.google.com/site/machinistsite/TWO-BUDDIES
                        http://s178.photobucket.com/user/lan...?sort=3&page=1

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