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  • New Member Intro

    Hello all. I was doing a search tonight on Google about Atlas lathes and it led me to this site.. decided to join and then realized that I had already joined a few years ago.. I sure don't remember though..

    Anyway I am into mechanics in general and have gotten into lathes during the last few years. I currently have an Atlas 12/36 which despite countless hours and years, I am pretty much unhappy with. I can live with poor finishes, but when I turn a piece, it it off a couple thousands or so within 2 or 3 inches.. Maybe this is the norm for these lathes (?). I am restoring a SB 10L that I have had for too long.. I started working on it a while back, but got side tracked.. I am modivated now to continue due to my dissapointment with my Atlas. I know that maybe I am overlooking something, and shouldn't blame the machine, after all, I am pretty green.. My first late was an Atlas 6/18 that I wish I still had. I would post some pics, but I guess pics are not allowed in this section of the forum. Thanks for reading my intro!

  • #2
    Welcome back Chuck. I'm surprised you are unhappy with your 12/36 but seem to have been happy with the 6/18 Atlas. Bigger is usually better. Have you checked your 12/36 for twist in the bed? Check for level, sure, but twist could probably better explain the poor accuracy. Be sure to keep us updated with your SB 10L progress. For pictures, I usually upload them to photobucket and then copy/paste the link into my post here.
    Cheers,
    Gary

    Comment


    • #3
      Thanks Gary.. Well to be honest, the 6 inch Atlas was my first lathe. It was pretty crusty when I got it, so I did a restore. I had fun with it, but never really used it to it's full potential..I didn't have it too long. I saw the 12" on Craigs List and grabbed it. Where I live, lathes are hard to find. I got rid of the 6" soon after. Knowing what I know now, I wish I had that little lathe to push to it's limits... I never gave it a chance.

      I have the 12/36 pretty much level with no twists, as far as I can tell.. many hours spent on doing this.

      As far a the pics, when I look below, it states " You may not post attachments" and "HTML code is off".. let me give it a try though..

      here is my 6" when I got it:



      Click here for Youtube video after I was done.



      well, I guess it does work! Should I post some more pictures here or is there a better section for that??

      Comment


      • #4
        [QUOTE=
        well, I guess it does work! Should I post some more pictures here or is there a better section for that??[/QUOTE]

        This would be the place, we love pics. I'd suggest being very specific describing your frustration with the Atlas to us. This group can offer a lot of advice on stuff to check. After a thorough restoration, big DC motor with speed controller, and so on, my 12 inch Atlas is my lathe of choice most of the time. After adjusting bearing tightness, ways and slide work, and meticulous leveling and alignment, I can expect very good results now.
        The above question on bed twist was certainly a valid first question because the lathe is quite able to do that and results in diameter differences, but are the headstock bearings properly adjusted? The tailstock was in use, wasn't it? Are the gibs snugged up? ....you get the pic.

        Comment


        • #5
          My biggest concern is when I use the tailstock with a 10" (X 1 1/2" OD) piece or chuck up a short 6" piece of the same diameter, by itself and turn it, it is not concentric. . The diameter is smaller towards the tailstock. I usually turn about 4 inches of the piece, and within that distance, there is about a .002 difference. I have tried taking light cuts (.004) and deep ones.

          I know my ways have some wear towards the headstock and I can lift my carriage up about .007. No way to shim this tighter. Adding shims will give it more play. The one shim that was in there has been removed.

          I have checked the headstock spindle with a dial indicator for up and down play/runout and can detect no play. Just thinking, maybe I should check the runout while I am turming something (if possible) ??

          Maybe this .002 difference should be expected?


          I have spent time leveling. I made it as level as I could without tightening down the bases under the bed too tight as not to do any twisting. . They are nice and snug and the legs are tapconed to the cement floor. I have redone this a couple of times using a short percision level.

          I have tightened all gibs enough to to remove all the play.. even tried them too tight just to see what would happen.

          I know my tailstock isn't aligned perfect. I was going check it with a 60 degree cut 2X4 piece chucked up in my 3 jaw and a dial indicater. I saw this method somewhere.. I don't see how this method would work though if the chuck allows .003 runout(?) or any other method it the tailstock isn't aligned to begin with, short of buying an alignment bar.

          My finish isn't that great either, but I am just learning to sharpen HSS bits and am really not too concerned with this. I also have some welded carbide and some inserts that I have used.

          Here is an older picture of my lathe. I have since bought an Aloris AXA QCTP and no longer use the turret type. I also now have it screwed to the floor.

          Comment


          • #6
            My noodlelathe cuts very well over a few inches. Your's is far nicer than mine - mine's a featureless 1937 model.

            There no reason for your lathe to be inaccurate. The gang here can help you diagnose it.

            Welcome back to the site.
            Last edited by Tony Ennis; 02-20-2013, 01:37 AM.

            Comment


            • #7
              Originally posted by ChuckB View Post
              My biggest concern is when I use the tailstock with a 10" (X 1 1/2" OD) piece or chuck up a short 6" piece of the same diameter, by itself and turn it, it is not concentric. . The diameter is smaller towards the tailstock. I usually turn about 4 inches of the piece, and within that distance, there is about a .002 difference. I have tried taking light cuts (.004) and deep ones.

              I know my ways have some wear towards the headstock and I can lift my carriage up about .007. No way to shim this tighter. Adding shims will give it more play. The one shim that was in there has been removed.

              I have checked the headstock spindle with a dial indicator for up and down play/runout and can detect no play. Just thinking, maybe I should check the runout while I am turming something (if possible) ??

              Maybe this .002 difference should be expected?


              I have spent time leveling. I made it as level as I could without tightening down the bases under the bed too tight as not to do any twisting. . They are nice and snug and the legs are tapconed to the cement floor. I have redone this a couple of times using a short percision level.

              I have tightened all gibs enough to to remove all the play.. even tried them too tight just to see what would happen.

              I know my tailstock isn't aligned perfect. I was going check it with a 60 degree cut 2X4 piece chucked up in my 3 jaw and a dial indicater. I saw this method somewhere.. I don't see how this method would work though if the chuck allows .003 runout(?) or any other method it the tailstock isn't aligned to begin with, short of buying an alignment bar.

              My finish isn't that great either, but I am just learning to sharpen HSS bits and am really not too concerned with this. I also have some welded carbide and some inserts that I have used.

              Here is an older picture of my lathe. I have since bought an Aloris AXA QCTP and no longer use the turret type. I also now have it screwed to the floor.

              ]
              Well, some things can probably help you. The lathe bed is the toughest. When worn, typically the outside half inch of the front way and worse at the headstock, a taper is to be expected. Also, the slop resulting in the carriage allows hog in issues when the force of the cut lifts the carriage that much in front. I corrected this on my first Atlas 10 inch without having the whole bed ground by a combination of light grinding with a fixtured appliance and scraping, but my objective was simply to create even wear down the entire front of the way and keep it as precise as I could by using mikes and straightedges with die blueing. Took a long time, but I had to do something and a professional grinding of the bed would have cost me more than the lathe. When the bed was uniform, I could take a few leafs off the shim stock allowing the carriage clamp to close tighter on the bed. Twerked well!
              I think you refer to two types of issues on the diameter, though. You say the chuck runs out. A couple thousandths runout on a 3 jaw is quite normal, even good for some chucks. That will not affect the method of setting tailstock position with a chuck mounted indicator because there is no change in the relationship of the indicator and the chuck, so it will rotate about the lathe center fine. Another method I have used is with a sturdy piece of all thread, center drilled both ends, a washer clamped between two nuts on each end of the all thread. Drive it between centers with a dog. Turn the washer to a diameter at one end, move to the other washer without adjusting the cross slide and turn that washer. The difference in diameter is twice the tailstock offset. The only advantage of a precision set up bar is more rigidity than the all thread has, but take light slow cuts and this method works fine. Thinking out loud I wonder if this tends to compensate for carriage droop on a worn carriage?
              Working on stock in the chuck with no tailstock support can be a problem aggravated in the smaller lathes. Any bearing slop or flex will allow the work to be pushed away from the bit, then the bit gets a bite and digs deeper as the chuck pulls back on center. The result is a rough finish. If this sounds familiar, check your bearing adjustment in the headstock. If it has been a long time since it was set up, the bearings might need a bit of tightening up. Snug them with the adjustment nut on outboard end of spindle until the headstock (belt very loose) rotates firmly without play but not stiff. Check your work by running a few minutes and feeling the headstock for warmth, if they get hot they are too tight. Those Timkin bearings should be just fine in that nice looking lathe.
              Some stuff to think about. Hope it doesn't make you sorry you dropped by.

              Comment


              • #8
                Thanks Gary, (and Tony), Some good info here. I will procede with the tailstock alignment, but will check the headstock first. It does sound familiar..

                I remember when I first got this lathe a while back, I took the headstock apart for a repair. I tightened it up, but not by using the procedure you mentioned. Hmmm... definitely something to check out. I will let you know how loose it is.

                As far as the bed goes, when I took the shim out of the rear of the carriage, it was too tight.. had to put it back in. The front is a different story.. no shim and still too much play. Might attempt something down the road, but maybe not. I will continue the restore of the South Bend but play with this one in the meantime.

                Im glad to be here, thanks!

                Comment


                • #9
                  "My biggest concern is when I use the tailstock with a 10" (X 1 1/2" OD) piece or chuck up a short 6" piece of the same diameter, by itself and turn it, it is not concentric."

                  Actually it is concentric, but it's tapered. Everything you turn on the piece without changing the setup will be concentric.


                  "The diameter is smaller towards the tailstock. I usually turn about 4 inches of the piece, and within that distance, there is about a .002 difference. I have tried taking light cuts (.004) and deep ones."

                  Sounds like the tailstock is out of adjustment. There's a screw near the base of the TS that moves it toward or away from the tool. If the TS is too far away, the work is larger at that end. Too close, and it's smaller. You only need to move the TS one half the difference between the chuck end and TS end diameters.

                  The height of the TS has very little effect on taper because of the trigonometry involved.
                  Last edited by winchman; 02-20-2013, 03:00 AM.
                  Any products mentioned in my posts have been endorsed by their manufacturer.

                  Comment


                  • #10
                    Just an update. I tightened the spindle play until the bearing got warm, then I back off till it was no longer warm. I then checked the alignment of the tail stock using dead centers. I found it was sitting very low. Now I have been told that the up and down alignment is not important, its the side to side alignment that counts, but If I drilled a hole using a chuck in the tailstock, it would be crooked. I took it apart and measuring the base, found that the front was up to .0015 worn compared to the back. I cut 6 different sized shims and compensating for the JB weld, positioned them. After rechecking, it was much better. I then aligned the tailstock from side to side. I have been practicing with different speeds and also spending time sharpening HSS. I now realize that with an old machine and just learning, that things might not be perfect, but with effort, they will work out. I made a quill lock for my old drill press and it came out pretty good. The cut still seems a little rough, but I can clean it up with emory cloth. I will keep praticing and should get better with time.

                    I had one to copy from my other drill press, which is on the right:

                    Comment


                    • #11
                      Originally posted by ChuckB View Post
                      Hello all. I was doing a search tonight on Google about Atlas lathes and it led me to this site.. decided to join and then realized that I had already joined a few years ago.. I sure don't remember though..
                      How about adding your location to your information? There may be some one just around the corner who could be of assistance to you.
                      Bill

                      Being ROAD KILL on the Information Super Highway and Electronically Challenged really SUCKS!!

                      Every problem can be solved through the proper application of explosives, duct tape, teflon, WD-40, or any combo of the aforementioned items.

                      Comment


                      • #12
                        I saw a YouTube video about feed rates for Atlas lathes and the person states that .0042, the slowest rate for my lathe, is too fast a feed rate for a really smooth finish. This person made an independant motor drive for his lead screw so he could make the feed rate slower.

                        Maybe I need to grind a bit a with a little wider cutting area to compensate for this?


                        Here is a video I made last night:

                        Comment


                        • #13
                          Sounds like you headed in the right direction. Finish didn't look too bad, but video isn't the same as seeing it first hand.

                          I prefer a few strokes with a file rather than abrasive paper to keep the abrasive out of the lathe, as far as possible. Or I cover up the ways before I break out the emery cloth.

                          You are correct that slower feeds and/or higher speeds or both tend to improve surface finish. The type of steel or other alloy also has a huge influence on what you can get for surface finish. Some steel is so stringy/tough the surface finish looks like crapola no matter what you do. The bigger, the more massive, the more rigid you machine is, the better the surface finish can be. But there's only so much you can do until you buy a different machine. Three phase motors tend to give a little advantage over single phase. Sharp acute angles on the tool definitely make a coarser finish.

                          Welcome back by the way.

                          doug

                          Comment


                          • #14
                            I bean here a while but never posted so i hope i dont get chewed out for doing this wrong
                            Just this past saturday i brought home a south bend lathe, it is still on the trailer but tomorrow is the unload day.
                            I have realy bean diging hard to find out how old this lathe is, so far nata.
                            Hopeing some one here can help me. The numbers on the tail end of the bed are: 1376HKR8 the R8 is clear to me
                            On the front cover is a brass factory pate with this info : Swing 16, Bed lenght 7' , Catologe No. 8117D i did find what the D stands for, it means Raised with a larger head bore. The bore dia. is 1 1/2 "
                            Can some one help me ?
                            If i miss posted please give me proper derections
                            Thanks
                            GEP

                            Comment


                            • #15
                              Originally posted by ChuckB View Post
                              I saw a YouTube video about feed rates for Atlas lathes and the person states that .0042, the slowest rate for my lathe, is too fast a feed rate for a really smooth finish. ......................Maybe I need to grind a bit a with a little wider cutting area to compensate for this?
                              ]
                              I agree that the slow feed rate on the Atlas is faster than one wants for a really fine finish and for that reason I usually hand feed the last pass. It is, however, possible to change a gear or two ahead of your quick change to slow down the drive train, but then you'd have to change back to get the threading speeds right and it's not worth it to me.
                              While you're experimenting, try adding the tailstock to the work. Many times it will surprise you how much the outboard support improves the finish.
                              A 1/16 radius on the tip should be more than enough for a nice finishing tool. I grind a typical left hand cutting bit and then add a chip breaker radius groove down the leading edge. A nice generous radius even bigger than 1/16 at the tip causes the right edge of the bit where it intersects the chip breaker radius to present a shearing edge almost 40 degrees IIRC to the work. With this bit I can make a deep rough cut toward the chuck and without changing the slide I slowly wind the bit back off the work. The shearing edge makes a glass smooth finish on aluminum and very good on some steels.

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