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  • Restoring Atlas 9 inch lathe: So close but . . .

    I am restoring an old 9 inch Atlas/Metalcraft lathe that was given me, with the advisement of a number of you on this site. The only part I found “terminal” was one of the bevel gears in the lead screw gearbox. The other two gears in the gearbox were fine. I spoke with the folks at Clausing, and the closest they had was the similar gear for a 10 inch Atlas. It arrived today ($68 later). Best I can tell visually, it has an identical gear pattern, and holding it adjacent to the mating gear it seems to mesh fine. While the 10 inch Atlas has a 3/4 inch leadscrew, and my 9 inch has a 5/8 inch leadscrew, I was told (correctly) the end of the screw upon which the gears ride is the 5/8 diameter, because that in fact is the ID of the gear. So everything fits. See photo #1 . . . Good news!




    But now the rest of the story. The bevel gear top design, that forms the socket that the sliding shift collar mates with, is quite different . . . See Photo #2. For comparison, I'm showing the new gear, and the other "old" gear that is still in good shape. (Hope I'm explaning this well enough)



    What do you think? Can it be modified, ie can material be removed from the “toothed” design to accept the almost half circular shift collar male “tab”. Not knowing better, it looks like if I had a mill, I could open up the teeth to make the same socket design. What do you think? Alas, I don’t have a mill. Is it feasible? Could I ask someone to help me on this? Or should I send it back to Clausing? I’m at a crossroads here and I sure could use some advice/help. Thanks.

  • #2
    Wow! I'd send it back. For $68 I'd cast a new gear myself. What's wrong with the old gear? (Besides a little wear) I use my crossfeed for facing and that's about it. If you want to keep the new gear, I think it would be much easier to make a new shift collar to fit the new gear.

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    • #3
      I'm down in Hillsborough and have a mill, but the question that jumps to mind is if the gear is hardened.

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      • #4
        Originally posted by Wess
        I'm down in Hillsborough and have a mill, but the question that jumps to mind is if the gear is hardened.

        I aint Paul but No atlus gears are made of zammick a pot metal material alum. and zink and i dont know what else cuts easy but cant weld.Some body close help this new guy I would but to far away.
        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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        • #5
          If I am not mistaken, those are the two gears which drive the lead screw. The 9" lathe does not have a power crossfeed. The shift collar slides back & forth for forward & reverse of the lead screw. I believe the used gear in the photo is the remaining good gear of the two originals.

          Without having the gearset in hand, it looks as though the new gear can be modified by milling to match. It should not be difficult to do on a milling machine, the gears are not hardened.

          With that said, probably 90% of lathe work is done with the carriage travelling from right to left, and some lathes do not have a reversable lead screw, reversing being done by adding another idler gear in the gear train. It would not be too much of a loss to simply eliminate the gear box alltogether and use a solid coupling to join the stub shaft to the leadscrew. The reversing gearbox is one of the weak points on the Atlas lathes, and was ultimately replaced with a set of tumbler gears for reversing.
          Last edited by JCHannum; 01-12-2007, 10:43 PM.
          Jim H.

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          • #6
            Paul,

            There's a yahoo discussion group devoted to the Atlas/Craftsman lathes and you might find better specific help there. That group is http://groups.yahoo.com/group/atlas_craftsman/ .

            The newer gear is a nicer design for the dog clutch, but the best shot is probably to modify the one you've got to match the old parts. (The alternative being buying another bevel gear and central shift part.) You can actually contrive to do some light milling on the lathe and it might be sufficent for this job, particularly given that the part is Zamak. As a for instance, you could mount the new gear on a short shaft matching the leadscrew stub, mount that in a boring tool holder that has a straight hole, clamp vice-grips to the outboard end and you've got a two-bit rotary table. The milling cutter of course is chucked in the lathe spindle. There's more to it, but you get the idea.

            jm
            .
            "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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            • #7
              Paul_NJ,

              Can't tell for sure what would be involved from the photos but is it possible to make a new replacement for the shift collar and match one side to the new gear? The collar seems like it would be easier to make without any special tooling. It also appears to have an integral key but if the new part was made from steel the key could be silver soldered in.
              Last edited by Mike Burdick; 01-13-2007, 01:04 AM.

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              • #8
                Originally posted by JCHannum
                If I am not mistaken, those are the two gears which drive the lead screw. The 9" lathe does not have a power crossfeed. The shift collar slides back & forth for forward & reverse of the lead screw. I believe the used gear in the photo is the remaining good gear of the two originals.

                Without having the gearset in hand, it looks as though the new gear can be modified by milling to match. It should not be difficult to do on a milling machine, the gears are not hardened.

                With that said, probably 90% of lathe work is done with the carriage travelling from right to left, and some lathes do not have a reversable lead screw, reversing being done by adding another idler gear in the gear train. It would not be too much of a loss to simply eliminate the gear box alltogether and use a solid coupling to join the stub shaft to the leadscrew. The reversing gearbox is one of the weak points on the Atlas lathes, and was ultimately replaced with a set of tumbler gears for reversing.

                You've deciphered correctly what I failed to explain clearly. The "other" part I showed is the "forward" gear, which attaches to the change gear and drives the leadscrew - I showed it only give a look what the end "socket" looked like on both gears. Here's the way they are arranged in the gearbox:



                Actually there's a third gear on top which I suppose is an idler gear. Excuse the pencils and screws . . just trying to hold the gears from rolling while I took the photo. This old lathe is my foray into metal working which I really hope to use for learning . . .but my only metal experience right now a cutting torch and a drill press: and neither skill seems particularly applicable toward this current dilemma. So making my own gears or remachining the shift collar aren't options. I haven't even run this lathe yet.

                But you told me something I didn't know . . . I didn't realize the gear I'm trying to replace is the reverse direction gear . As you said, perhaps I should save the $68 and a lot of trouble, and just use the lathe's forward automatic cutting capability, then shift to neutral, and crank it back by hand with the wheel handle. Gee, am I interpreting the situation and your words correctly? Is there any other reason I'd want to go backwards automatically? If not, then why bother replacing it? Perhaps that's what the previous owner had done all along as the damaged worn gear had been actually turned around backwards on the lead screw.

                Thanks

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                • #9
                  I'm still confused. I have a Manual for the lathe, and while it tells next to nothing about how to set up the lathe, it does have a parts blowup. And the blowup labels both gears as leadscrew reverse gears, "left reverse" and "right reverse" gears. Oh brother, what's up with that? (Interestingly those gears cost $.40 back in 1930).

                  Are we sure the right side gear is reverse and the left forward? I'd sure hate to send the new gear back and discover it was the forward gear.

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                  • #10
                    Paul,

                    Keep the gear...$58.00 is NOT that much. Measure and detail the shift collar and then put the lathe back together with the old parts. Now you can use the lathe to make the collar. Make one side to fit the new gear and the leave the other side as is. It looks like all you'll need is the lathe, a hacksaw, and a file. It'll be a good first project and you'll learn alot. Nothing teaches better than when one "has to do something"! Be glad you have this opportunity!

                    The gear is $58.00 today and will probably be $100.00 when you decide that you need it to make left hand threads, etc. (and you will).

                    You might have to make the part several times before you get it right, but believe me, after you get the part to work you'll never look at a broken tool the same again. Yep, you'll start thinking junkyards are shopping centers!
                    Last edited by Mike Burdick; 01-13-2007, 01:58 AM.

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                    • #11
                      Myself, if I already had the gear in the garage, I'd go ahead and mod it, but if I were buying it, I'd have to look for the right one, unless I could find one that was as easily modded as this one for a lot less.

                      A Dremel type tool, would work nicely to remove the lugs if you don't have access to a mill, one corner would need file and knife/scraper work to make the corner directly but if all other aspects are the same it should work nicely.


                      May be better to look for the correct gear, check ebay, and people on the atlas group, someone may have one.

                      My grandkids played around in the garage and left a gear from my atlas out in the driveway where I ran it over, and someone on PM emailed me and said he had a few gears for the atlas lathes, don't remember who though, and I think I purged my emails, but I'll look.

                      My atlas has the same reversing box as yours does, keep it lubed, I understand it needs to be turning when switching, and use gentle but firm pressure, everything in there seems to be the same zamak material, haven't broken mine yet, but I'm not rough with it, seems you need to develope a feel for it, mine was difficult at fiirst to engage, but wiuth practice you learn the right pressure. think mine's a 'war' model, no chrome on it anywhere, but every one I've seen that's similar has chrome wheels etc.

                      The way the gears are set up, if you can not get that box fixed or find the right one, you could place another gear with the same tooth count as the spindle gear in the train to reverse the leadscrew if needed.

                      the other bevel gear is the drive gear, the broken one is the actual reverser, no matter what direction your turning the one with the long shaft is engaged with the thread gears, as long as that one will engage the collar, it will turn the screw.
                      Slipping a gear in that's the same as the spindle will reverse it at 1:1 so the gear charts will read correctly, if you need the 'reverser' gear in the thread setting, double up one of the other gears.

                      Then use the box as just an 'on - off' switch untill you can find the correct gear.

                      Ken.

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                      • #12
                        name of the guy over on pm is Rex TX

                        a fairly recent posting from him regarding the shifter box is here:

                        http://www.practicalmachinist.com/ub...c/25/1792.html


                        ken.

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                        • #13
                          Ken: Thanks for the clarification on how this lathe works and the ideas. I'm learning more each time, and saving postings like yours into my own "operators manual".

                          Mike: Thanks for the suggestions and particularly the encouragement.
                          but believe me, after you get the part to work you'll never look at a broken tool the same again. Yep, you'll start thinking junkyards are shopping centers!
                          . I like that thought . . . I would really like to be able to accomplish that capability! I'll keep the gear and give it a try.

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                          • #14
                            Can't you use a file on it?

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                            • #15
                              Originally posted by Al Messer
                              Can't you use a file on it?

                              Not sure what you mean . . .

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