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Help - stuck chuck, stripping gears on Craftsman 6x18

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  • Help - stuck chuck, stripping gears on Craftsman 6x18

    Hello all.

    I have come upon a conundrum, folks. I have a Craftsman/Atlas 6x18 lathe, and I decided to try to take the chuck off. I'm looking at trying to find a new chuck, and some other things, so I thought I might try to check what size threads are on the spindle.

    So after reading a little about how to remove a chuck from a threaded spindle, I went at it. I engaged the back gear and pushed on the chuck using the chuck key, in the opposite direction of normal rotation... well, that didn't work! I huffed and puffed and strained and grunted, and nothin'.

    So, I stepped it up a notch. I put a crescent wrench on one of the jaws. I tapped on it lightly with a hammer, sprayed the chuck with some WD40... well, nothing.

    After that, I decided to just put as much pressure as I could on the wrench. Now, here's my problem: in doing that, I've chipped off about three teeth from both the back gear and spindle gear. It still works and I rarely use the back gear anyhoo, but uh...

    Thing is, if the chuck hasn't come loose and yet it's stripping gears... what the heck do I do now? It's like a catch-22.

    Looking for a little advice, fellas. I know stuck chucks come up pretty often, but... this one's a little different. Thanks, all.

  • #2
    Looking at your chuck from the tailstock, your chuck will come off counter clockwise. It is a right hand thread like a common bolt with a nut. I find that a solid rap with a heavy hammer gives a better impact to loosen a stuck chuck. Since you have already chipped the back gear teeth, I would use them to loosen the chuck. After that I would not use them until you replace the gear. It would be bad to lock up the gear train while using the lathe. Mike

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    • #3
      If you already broke teeth on the back gear, what's the point in trying again?? I've had good luck using a plumbing strap wrench on the cone pulley and a big piece of hex stock in the chuck. Use a breaker bar and socket on the hex stock, and allow the strap wrench to butt up against the machine casing. Put some plywood over the ways so that when the breaks loose you don't bash the ways with the breaker bar. If you don't have access to the hex stock, you can put a bar across between the jaws, but that's less desirable. I'd also mark the chuck and squirt penetrating oil onto the end of the spindle inside the chuck. Let it sit for a while, then rotate the chuck a quarter turn and repeat.

      Another method that I've seen discussed is to cut a block of wood the length of the space between a horizontal jaw on the chuck and the bed ways, and turn the cone gear.

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      • #4
        Personally I would chuck up a hex bar in the chuck and stick an impact on it without the backgear or lead screw gears engaged.
        Andy

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        • #5
          Originally posted by Mike279 View Post
          Looking at your chuck from the tailstock, your chuck will come off counter clockwise. It is a right hand thread like a common bolt with a nut.
          Oh, you guys are gonna hate me, heh... this was my problem all along. I had read somewhere the exact opposite, and figured the lathe would turn the same direction as tightening the chuck, so I went with the opposite of that... bah. I got it off easy-peasy. Just a few light taps and off it came... I put it back on basically with the same, hand-tight and then half a dozen light taps with a hammer and wrench. I assume that is sufficient?

          Thanks for helping me out, all. Sorry for taking up your time with such a dumb mistake, agh.

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          • #6
            Don't beat yourself up too badly, we have all been there. Joe

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            • #7
              It's an expensive lesson that you have learned. For a tight chuck I put the short arm of my biggest Allen key in the chuck and tap the long end. I did it recently on a lathe that had not had the chuck removed for around ten years, one tap with a hammer was all it took.

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              • #8
                Paging Sir John! Could you please come to the front and advise this poor man.
                How to become a millionaire: Start out with 10 million and take up machining as a hobby!

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                • #9
                  Clumsy bastard
                  .

                  Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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                  • #10
                    Originally posted by TN Pat View Post
                    ... I put it back on basically with the same, hand-tight and then half a dozen light taps with a hammer and wrench. I assume that is sufficient?
                    When installing the chuck, don't wap it, tap it or slap it. Just bring it up hand tight.

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                    • #11
                      Nice to hear you got it off. I like to get the chuck almost to the register and give it a quick snap of the wrist to bring it home. A little less than a eighth of a turn. This has been plenty to hold them on and not enough to make them hard to get off. From an old College shop class. Mike

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                      • #12
                        When you re install take a lesson from the oil patch and use a good anti-seize compound not grease which is slick. If you encounter this problem again leave it out of gear grab some hex stock and a good impact. 3/4 impact works best.
                        Byron Boucher
                        Burnet, TX

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                        • #13
                          Originally posted by Boucher View Post
                          When you re install take a lesson from the oil patch and use a good anti-seize compound not grease which is slick. If you encounter this problem again leave it out of gear grab some hex stock and a good impact. 3/4 impact works best.
                          Originally posted by vpt View Post
                          Personally I would chuck up a hex bar in the chuck and stick an impact on it without the backgear or lead screw gears engaged.
                          This has been my experience as well. Anti-seize on the threads and on the register, then just hand tighten until the chuck/backplate meets the spindle.

                          A good 3/4" air impact and piece of hex shaped stock in the chuck will do wonders for removing a stuck chuck. The sharp impacts do the work so the more rigidly you can secure the spindle the more successful this approach will be.
                          You have unfortunately already found out why not to use the back gears for this purpose but it warrants repeating for others that those parts of the lathe were never designed for that purpose. Do whatever it takes to secure the spindle solidly without damage.
                          Home, down in the valley behind the Red Angus
                          Bad Decisions Make Good Stories​

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                          • #14
                            I also broke some teeth from the back-gears because I didn't realize it would climb out of complete engagement. I held it in place and stuck a crowbar in the jaws and whacked it with a hammer. It came loose. Fortunately a nice guy in Tulsa was given (2) 9" SB lathes he had no use for. He gave me the "A" apron, gear-change box, and back gears to upgrade my model "C" change-gear lathe. A friend milled the groove in my lead screw to run the power cross-feed. My spindle is 1-/2 X 8. He even gave me the gear that enables me to cut metric threads.

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                            • #15
                              I will repeat something worth remembering for safety-A friend's father who owned a machine shop was gutted and thrown over the lathe because he broke his own safety rule trying to remove a HUGE chuck by putting the chuck wrench into the socket and turning the lathe on, but accidently hit reverse while it was in front. It hooked him under his rib-cage. UGH !

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