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  • Atlas cross slide malfunctioning

    So I've been learning some basic machining on the Atlas/Craftsman Commercial 12" lathe. Lately I have not been able to bring the crosslide back very well. It feeds forward smooth, but it takes significant pressure to bring it back. Sometimes it will come back smoothly but this is getting to be more rare. Feels like something is binding or I'm not sure. I loosened the gibs on the cross slide and actually took the compound and the nut that moves the compound off to see if that could be causing the problem, but was still having the same problem. I oiled the oil holes.

    Any ideas of what could be going on? Is there a gear that the power feed mechanism uses which could be causing the problem? Thank you in advance.

  • #2
    When you retract the crosslide toward you, the pressure on everything is opposite what it was for cranking it forward. Specifically, the dial side of the screw bearing has pressure on it. That includes also the dial, as the stackup includes the dial on most Atlas, IIRC. If the area behind the dial is not oiled, or if it has dirt in it, that will certainly change the friction.
    1601

    Keep eye on ball.
    Hashim Khan

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    • #3
      My HLVH has a long tapered wedge on the cross slide. If it is not tightly held by the adjuster at each end, it can move forward and back when the cross slide is reversed, causing exactly what you describe. This happened when first adjusting the machine after cleaning - seems stuff I buy has always sat long enough to need a near complete disassembly and cleaning.

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      • #4
        I'm hoping I won't have to take it all apart but If I have to to clean it then I probably will. The hard part is getting it all back together and working properly. You do learn quite a bit with disassembly and reassembly.

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        • #5
          An Atlas lathe does not have a tapered gib like a Hardinge.
          It is like comparing Yougo to a Ferrari.
          The Atlas has 3 set screws on the compound gib.
          When I owned my POS Atlas, I added 2 more,
          for a total of 5 set screws. This was to help with rigidity.
          Is your gib cast iron? I have seen some late Atlas lathes
          with nylon plastic and also steel gibs. I seem to have read
          somewhere that the 600 Group was passing off mild steel
          strips as Atlas gibs. This trash just won't work, even on a
          POS lathe.

          --Doozer
          DZER

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          • #6
            I had a Craftsman Commercial about 15 years ago. In many ways it 's the best of the Atlas lathes, the heaviest bed, yadda,yadda. This does NOT include the gibs, which, at least on mine were some sort of nylon/plastic material.

            Your best bet would be a disassemble and inspection of the cross slide, and gib. I found my gib had cracked in the area of the adjusting screw seats. I made new ones from scratch from brass strip. I sawed 'em from some plate, filed the angles, and used a transfer punch to mark the dimples where the adjusting screws
            seat. I cut the seats with my drill press and whatever size drill it needed. It was a pretty crude fix, it reflected my abilities and equipment at that time. What a difference!

            I didn't experience the same symptoms as you, I was having trouble with overhanging tools. (boring bars) Sorry I can't remember what size stock I used, the machine has been gone a long time now, probably 12 years or so.

            Best of luck, and keep us posted on what you find
            TC
            I cut it off twice; it's still too short
            Oregon, USA

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            • #7
              I think the gibs are ok because I was still getting the problem with the compound removed from the lathe. I will likely try to take the apron/cross slide off the lathe and try to disassemble it and clean it. To me it seems like the problem must be close to the handle but I guess you can't see inside it until it's disassembled. I did in fact remove the handle along with the dial but this didn't solve the problem either.

              It's just a weird problem because sometimes it will work fine, but then other times I have to use all my strength to be able to retract it.

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              • #8
                Check the nut under the ballcrank on your slide. If loose and not secure, it can/will tighten against the dial when the screw is turned counterclockwise to retract the slide.

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                • #9
                  Originally posted by Gary Paine View Post
                  Check the nut under the ballcrank on your slide. If loose and not secure, it can/will tighten against the dial when the screw is turned counterclockwise to retract the slide.
                  I think this solved it. I just went out and tightened the outermost nut from the handle and it seems like it is working again. Thank you so much!

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                  • #10
                    Hey Dooz.....

                    What's wrong with mild steel on that type gib?

                    What do you think is better?

                    Lots of machines use that, and it works. I've even used brass. The material's not very critical, even the plastic ones probably kinda work.
                    1601

                    Keep eye on ball.
                    Hashim Khan

                    Comment


                    • #11
                      He's in the wrong forum. He believes that unless you have the best of everything, your tools are trash. Many forget this is a Home Shop machinist forum.

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                      • #12
                        Yabbut, what is actually "not the best" about them?

                        I surely do not think cast iron would be better it would probably shatter. if not that, then what?
                        1601

                        Keep eye on ball.
                        Hashim Khan

                        Comment


                        • #13
                          "What's wrong with mild steel on that type gib?"

                          Mr.Tiers, scrape some mild steel.

                          Brass, bronze, cast iron all good. Hard steel, well that takes some work.

                          Dunno plastic. It gets better all the time but I wouldn't use it in this app.

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                          • #14
                            Originally posted by Carm View Post
                            "What's wrong with mild steel on that type gib?"

                            Mr.Tiers, scrape some mild steel.

                            Brass, bronze, cast iron all good. Hard steel, well that takes some work.

                            Dunno plastic. It gets better all the time but I wouldn't use it in this app.

                            OK, so what is wrong with mild steel for this useage? I've had loads of lathes and other machines with gibs made out of mild steel, usually around 1/2" -3/4" x 1/8" or 3/16". cast iron would be no good here, too thin. I've never found one with brass or bronze gibs. Yes, thicker, taper gibs are a better design, but in the case of a thin strip gib, IMO, theres nothing wrong with mild steel. Theres more issues with the detailing, like how many adjusting screws, what thread on the adjusting screws, what the end shape of the adjusting screws is, dowelling of the gib to prevent unwanted longitudinal movement, than there is in the material.
                            'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger

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                            • #15
                              i have taken apart, scrapped, some machines over time
                              old fashioned reasonable quality machines
                              i have yet to find one single, rather thin, non-tapered gib made out of cast iron, brass or bronze
                              they all were, rather mild, steel, either planed or milled or ground ,none of them had scraping
                              all of them had more wear near where the setscrews were
                              none of them were really flat any longer

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