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  • Gorton 9J Mill Help

    I've had a Gorton 9J mill sitting in storage for many years and decided to power it up to check everything out. The motor is absolutely quiet but the drive pulley on top of the spindle is making a knocking sound. Put an indicator on bottom of spindle nose and got 0.0005"-0.0007" runout so it didnt appear to be the bearings. Removed the belt guard and the pulley has some wobble to it where I can take my hand and move it. Took the top cap off the spindle where the splines are and there is a large spanner nut with lock washer that looks like it should tighten down on the pulley.

    Now my question,

    Do I attempt to tighten this nut snug enough to remove the play in the pulley and will this have a negative affect on the bearings? I'm not too experienced with spindle work so decided to leave it alone until I could get some expert advice.

    I've never had this machine powered since buying it so not sure how this nut could have backed off with the lock washer.

  • #2
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    • #3
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      • #4
        The nut didn't back off. It has a conical angle on the underside that makes it look like it did.
        Kansas City area

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        • #5
          The pulley bearings nut has nothing to do with spindle run out.
          In my 9-J manual, it lists the spec. for the spindle run out to be
          "less than .001", which yours seems to be.
          I would absolutely not worry about it.
          For your information, my spindle is #10 Brown & Sharpe taper
          that I have a shop made sleeve in, that converts it to R-8 taper.
          It is super nice. Just change the drawbar to 7/16-20 also.
          I lucked out on my 9-J. It was a war baby but somehow the
          scraping on the ways is in perfect condition. Super low use.
          The machine is twice as rigid as a Bridgeport.
          Welcome to the club.

          -Doozer
          DZER

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          • #6
            Originally posted by Toolguy View Post
            The nut didn't back off. It has a conical angle on the underside that makes it look like it did.
            You are correct, the lock nut is angled upward. There is however a gap that can be felt with a feeler allowing the pulley to lift up causing the rocking.

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            • #7
              Originally posted by Doozer View Post
              The pulley bearings nut has nothing to do with spindle run out.
              In my 9-J manual, it lists the spec. for the spindle run out to be
              "less than .001", which yours seems to be.
              I would absolutely not worry about it.
              For your information, my spindle is #10 Brown & Sharpe taper
              that I have a shop made sleeve in, that converts it to R-8 taper.
              It is super nice. Just change the drawbar to 7/16-20 also.
              I lucked out on my 9-J. It was a war baby but somehow the
              scraping on the ways is in perfect condition. Super low use.
              The machine is twice as rigid as a Bridgeport.
              Welcome to the club.

              -Doozer
              I was looking at the manual again and it mentions adjusting this pivoting part on the spline to remove some play. It took a while looking at the part after I degreased it but think I now understand how it functions. One of the spring loaded pins was cracked so it possibly was not putting proper tension on the spline-pulley fit.

              That #10 spindle is a real drawback to this machine. I ordered a 4" face mill for this mill and my K&T #2 (when I get that one running) and found what seems to be the last commercially available arbor from KBC Machinery but it doesnt fit the face mill properly.
              I've asked my neighbor who has a CNC shop to make me a drill chuck and boring head arbor so I'll have to see if I can add this one to the list.

              It would be real nice to be able to use R8 tooling in this thing.

              I havent tore into the table much to see the condition of everything but most of the machine is in pretty good shape. I got the big face mill because this machine looks ridgid enough to take light cuts with it, got a 2" one reserved for my little Bridgeport.

              I'm not on here much but I thank you guys for helping out.
              Attached Files

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              • #8
                Just needs some careful fitting with a BFH... (big hammer)
                Kansas City area

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                • #9
                  Pulled the nut off of the drive pulley and really didnt find anything damaged. The pulley did however have a nice thick coating of grease and filth on the underside.

                  Got everything cleaned up nice including the top side of the spindle bearing where some dirt went down inside.

                  Reassembled the pulley and nut, tightened it hand tight and the play is taken out. I believe what happened is someone may have taken the pulley off for some reason (to replace the oil cup under it) and they put the tabs of the lock ring in while it was rotated clockwise which allowed the nut to back off a little bit. The keyway tab in the lock ring is a little narrower than the keyway in the spindle so it would have allowed it to loosen just enough to allow the pulley to move.
                  Attached Files

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                  • #10
                    After talking to Doozer, I realized my machine is missing the "self ejecting" drawbar.

                    Made a quick prototype one to see if this is how it is supposed to be or am I missing something else.
                    Attached Files

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                    • #11
                      Flushed out the spindle bearings with carb cleaner and some marvel oil. Things seem to rotate better.
                      Attached Files

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                      • #12
                        Chris-
                        You have some problems that happened here.
                        Some time in the life of the machine
                        the bearing locknut that tensions the PULLEY
                        bearings got loose. It seems to have been
                        used with these pulley bearings running loose
                        for a long time. What happens when something
                        like this runs loose, is that it frets. Fretting is
                        a type of corrosion, identifiable by the distinctive
                        brick red color. It come from near constant
                        movement, even on a microscopic level, between
                        steel parts. Steel is self passivating. Just like
                        copper turns green when it passivates, steel
                        rusts just a little and then a protective layer forms
                        and rust drastically slows down. When you have
                        constant movement from something like your
                        bearing locknut being loose, this passivation
                        layer keeps forming and then gets rubbed away.
                        This is the red rust you see. What happened
                        on your mill, is the red rust formed and continued
                        to get washed down into the SPINDLE bearings.
                        So now you have this mess on your hands
                        right now. All because somehow, years ago
                        that pulley bearing locknut came loose.
                        If you take the Allen head pinch bolt loose
                        on the housing casting, the spindle bushing
                        will come down, and also a big compression
                        coil spring. After that, the spindle just comes
                        out the bottom. Then you can flush the whole
                        thing. Spindle bearings are probably pitted
                        and noisy and likely have lost their preload.
                        Depending on your intended use of the mill
                        you might want to replace them. This is a
                        whole deep other topic. If you are not familiar
                        it is a bit more involved than replacing electric
                        motor bearings. But maybe you now that.
                        But if you pull the spindle and flush everything
                        at least you stop the damage from happening
                        further,

                        ---Doozer
                        Last edited by Doozer; 08-08-2021, 11:46 AM.
                        DZER

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                        • #13
                          Click image for larger version

Name:	Gorton 9J Drawbar LH Thread Captive.JPG
Views:	272
Size:	14.8 KB
ID:	1955511

                          Check this out,
                          I snatched this off the internet somewhere.
                          A guy bored open the spindle ejection nut and
                          made it taller to accommodate a needle or
                          ball thrust bearing to make the drawbar
                          easier to eject. If I were to do this, I would
                          add needle thrust bearings top and bottom
                          of the drawbar flange, so it removed friction
                          in the tightening and ejection directions.
                          A smart mod really....

                          --Doozer
                          DZER

                          Comment


                          • #14


                            Walk around of my Gorton 9-J.

                            --Doozer
                            DZER

                            Comment


                            • #15
                              Originally posted by Doozer View Post
                              Chris-
                              You have some problems that happened here.
                              Some time in the life of the machine
                              the bearing locknut that tensions the PULLEY
                              bearings got loose. It seems to have been
                              used with these pulley bearings running loose
                              for a long time. What happens when something
                              like this runs loose, is that it frets. Fretting is
                              a type of corrosion, identifiable by the distinctive
                              brick red color. It come from near constant
                              movement, even on a microscopic level, between
                              steel parts. Steel is self passivating. Just like
                              copper turns green when it passivates, steel
                              rusts just a little and then a protective layer forms
                              and rust drastically slows down. When you have
                              constant movement from something like your
                              bearing locknut being loose, this passivation
                              layer keeps forming and then gets rubbed away.
                              This is the red rust you see. What happened
                              on your mill, is the red rust formed and continued
                              to get washed down into the SPINDLE bearings.
                              So now you have this mess on your hands
                              right now. All because somehow, years ago
                              that pulley bearing locknut came loose.
                              If you take the Allen head pinch bolt loose
                              on the housing casting, the spindle bushing
                              will come down, and also a big compression
                              coil spring. After that, the spindle just comes
                              out the bottom. Then you can flush the whole
                              thing. Spindle bearings are probably pitted
                              and noisy and likely have lost their preload.
                              Depending on your intended use of the mill
                              you might want to replace them. This is a
                              whole deep other topic. If you are not familiar
                              it is a bit more involved than replacing electric
                              motor bearings. But maybe you now that.
                              But if you pull the spindle and flush everything
                              at least you stop the damage from happening
                              further,

                              ---Doozer
                              Thank you for that detailed description, I was starting to think that machine had been left out in the rain and somehow didnt have rust anywhere but the spindle. Once I flushed it a couple more times and lubricated the bearings they turn pretty freely.
                              I printed out the full O&M manuals for the machine so I'll be pulling the spindle next weekend.

                              I have a good friend that owns a motor & prototype machine shop that is going to help me remove the bearings, clean the housing and install new bearings. He is experienced with machine spindles so I trust it will be correct when reassembled. I'd like to keep this machine for a while so may as well do it right while it is pulled apart.

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