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  • I think I may have solved a puzzle,

    For the past week or so I have been trying to bring a badly robbed and long disused Atlas Horizontal mill back to life.
    I was plagued with problems on the X axis. Initially the telescoping screws were rusted together and it took a lot of force and heat to get them to behave.
    However, even after they were moving smoothly the slide would, at random tighten up, stay tight for a while then , on reversing its movement and reversing it again slacken back.
    I would add that it is obvious the machine had seen a lot of use, its owner bought it for $ 35 as junk.
    After a lot of dismantling, head scratching and a few wrong diagnoses I found that the turned down ends of the gib adjusting screws were smaller than the recesses drilled roughly ( Chewed, worn ,created by aliens)?? ! in the gib strips and the strips were moving slightly lengthways thus they simply could not hold adjustment the screws and one in particular climbed and fell on the recess as the slide moved.
    My cure was to flat bottom the recesses in the gib strips with a slightly larger end mill and make new adjusting screws to fit .
    I simply do not have the skill, time nor energy to rescrape the slides for my friend, they all get a bit slacker in the middle of their movement, however, at least Z now does noe virtually seize at random now.
    I hope this will encourage and help someone, Regards David Powell.

  • #2
    Sorry meant to write Z axis, Getting old sucks. David Powell,

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    • #3
      Good job!

      I had to do similar with my milling machine, on the x-axis. The slot for the adjuster was malformed and a bit wider than the head of the screw.
      Peter - novice home machinist, modern motorcycle enthusiast.

      Denford Viceroy 280 Synchro (11 x 24)
      Herbert 0V adapted to R8 by 'Sir John'.
      Monarch 10EE 1942

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      • #4
        Nice find and fix! Gonna share any pics of the mill?
        Andy

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        • #5
          Thanks for the tip, David! Something for all mill owners to keep in mind.
          Jim

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          • #6
            Those recesses for the adjustment screws are always flat from the factory as far as I know. The several Atlas machines I have had apart have always had flat recesses, certainly.

            If they were drill-pointed, that suggests the gibs were either modified, or replaced by someone later.
            CNC machines only go through the motions.

            Ideas expressed may be mine, or from anyone else in the universe.
            Not responsible for clerical errors. Or those made by lay people either.
            Number formats and units may be chosen at random depending on what day it is.
            I reserve the right to use a number system with any integer base without prior notice.
            Generalizations are understood to be "often" true, but not true in every case.

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            • #7
              I know this would not be a proper fix for the getting tight at the ends problem but could you stone or otherwise thin the gib strips near the ends to avoid the tight spots at the ends of travel? Again, not the proper way but maybe a quick fix.

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              • #8
                Originally posted by wdtom44 View Post
                I know this would not be a proper fix for the getting tight at the ends problem but could you stone or otherwise thin the gib strips near the ends to avoid the tight spots at the ends of travel? Again, not the proper way but maybe a quick fix.
                An easier method to do the same thing would be to slack the gib screws at the ends of the gibs. Either would avoid the tightness at the ends of travel, but might create a "rocking horse" type looseness at all positions, where the slide can twist side to side. There's really no substitute for straight, flat, ways.

                I see the idea, though.
                CNC machines only go through the motions.

                Ideas expressed may be mine, or from anyone else in the universe.
                Not responsible for clerical errors. Or those made by lay people either.
                Number formats and units may be chosen at random depending on what day it is.
                I reserve the right to use a number system with any integer base without prior notice.
                Generalizations are understood to be "often" true, but not true in every case.

                Comment


                • #9
                  The jib screws on Myford lathes have one screw which fits in a hole in the jib to ensure that it moves with no slop.

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                  • #10
                    Originally posted by old mart View Post
                    The jib screws on Myford lathes have one screw which fits in a hole in the jib to ensure that it moves with no slop.
                    BY being very patient in adjusting the screws I have got all three slides to the point that the handwheels are slightly tight to turn at the ends of the slides travel, yet there is no major amount of looseness at the middle of the movements.
                    There is still a minor but perceptible " Bump" to the Z handle.s movement when the telescoping lift screw moves on to the next section.
                    I am hoping the machine's owner brings along a couple of strong friends to haul it away complete, otherwise we will have to dismantle it to get it up my basement stairs
                    Regards David Powell

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                    • #11
                      Winch it up, how heavy can it be ?

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                      • #12
                        Yes, getting old does suck. But the alternative sucks more.



                        Originally posted by David Powell View Post
                        Sorry meant to write Z axis, Getting old sucks. David Powell,
                        Paul A.
                        SE Texas

                        And if you look REAL close at an analog signal,
                        You will find that it has discrete steps.

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                        • #13
                          Unfortunately because of the vague title, this thread will likely never see the light of the day after it leaves the main page and the info will be lost.

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                          • #14
                            Originally posted by old mart View Post
                            The jib screws on Myford lathes have one screw which fits in a hole in the jib to ensure that it moves with no slop.
                            It sounds like the Myford is designed with a tapered gib that slides longitudinally for adjustment. The Atlas machines are straight gibs with several screws along the length, a simpler and less elegant solution. The tapered gibs could also be subject to jamming if the the slot for the screw head (or two opposing screws) are maladjusted. In one direction it could drag the gib along, closing the clearance and possibly freezing travel altogether.
                            .
                            "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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                            • #15
                              I'm sure I wouldn't have been the first guy to put knurled thumbscrews on (lathe) gibs, and adjust them while the machine's feeding to make up for wear...

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