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  • Leaky ZX-45 mill

    No big surprise there it is a common enough thing. It has been dripping slightly for a long time but in the last couple of weeks the drip is now a flood. I am assuming that the spindle bearing seals are gone, that is what most people complain of. It seems that all the manufacturers of these mills make them slightly different and getting replacement parts through the supplier that it came from is generally not possible. Even if I could get something out of a place like Grizzly there isn't any guarantee that they use the same parts in there mills. Would these be common parts that can be bought from a bearing supplier?
    The shortest distance between two points is a circle of infinite diameter.

    Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

  • #2
    The seals seem similar across the range of resellers for the RF-45 type mills, as do parts, and the seals are available from third party sources.
    I think your best bet is to open the head and see if the seals are installed where you can make out the printing on the rubber,
    in my case the seals were installed with the face down, I've also seen pictures of Grizzly versions where the seals are installed face up.
    You also might be surprised at what you find in there if you've never done any pre maintenance.

    Try these places for seals -

    https://www.avxseals.com/

    https://www.theoringstore.com/index....ndex&cPath=700

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    • #3
      All bearings and seals should be easily available at any bearing shop, they use the cheapest parts that are available, to make these machines at such a low price.

      Comment


      • #4
        If any of you have had this problem, is there any other place that the oil can leak from. The manuals exploded parts view is the typical excellent Chinese type, oil seal are labelled as air seals.
        The shortest distance between two points is a circle of infinite diameter.

        Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

        Comment


        • #5
          I haven't had any oil leak problem since my mill is currently dismantled and in the process of re assembling
          after some through cleaning.
          The mill head is basically a cast iron tub, other than the oil drain plug and the speed selector / gear
          selector shafts, and the quill power feed selector, that have openings into the head, there is only two places
          that would cause a oil leak in the spindle.
          The oil seals themselves and from the end cap that the oil seals are in, the end cap is rtv gasketed in place.
          Seals are # 6 the end cap is # 5 in the drawing from my manual.

          Comment


          • #6
            So it pretty much has to be the seals. How did you fine disassembling the head. Difficult, straight forward and what is needed to install the new seals. Any special tools etc.

            Your drawing is much better then mine.
            The shortest distance between two points is a circle of infinite diameter.

            Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

            Comment


            • #7
              There's a gasket under #5 in my old one, leaks like a sieve.
              Len

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              • #8
                I believe the standard repair is to use a sealant like permatex instead of a gasket.
                The shortest distance between two points is a circle of infinite diameter.

                Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

                Comment


                • #9
                  Originally posted by loose nut View Post
                  So it pretty much has to be the seals. How did you fine disassembling the head. Difficult, straight forward and what is needed to install the new seals. Any special tools etc.

                  Your drawing is much better then mine.
                  You'll probably need an assortment of metric tools ; allen wrenches, sockets, and wrenches
                  It's sort of straight forward, remove the motor, the top cover of the head has either RTV gasket or a paper/rubber gasket,
                  mine has the paper/rubber kind so you'll have to see what kind you have on your machine. A box cutter blade should take care of either one.
                  There are also 2 tapered alignment pins in the cover, they're odd in that they have a M5 threaded end.
                  I used plastic mold wedges to lift up the cover since the gear shaft end bearings are a tight slip fit, tapping the
                  wedges in at the four corners took the cover off easy.



                  Note there are 2 plastic caps with O rings in the top cover covering two of the speed and ratio gear shaft bearings, you can leave them be or drive
                  them out after the cover is off, helps that they're out when putting the cover back on, you can see if the bearings are aligned to the hole.
                  Drop the spindle, I did on mine since I was doing a fine clean out of the mill, it also gives you more access to install the seals.

                  I decided to pull the seals in with a jig rather than take part # 5 ( end cap ) off and press in the seals and RTV the cap back on,
                  the reason being is that I see no way of aligning that end cap with seals back in place properly since the splined tube ( # 57 ) that drives the
                  spindle goes into oil seals in the end cap and the bearings that go into the cover.

                  I made a jig to fit in the inside groove of the seal, I'll use a threaded rod to draw in the seals thru the quill bore, I'm doing that in the next hour or so
                  so I'll post my results.

                  Comment


                  • #10
                    Originally posted by loose nut View Post
                    The manuals exploded parts view is the typical excellent Chinese type, oil seal are labelled as air seals.
                    "look for exit spot on air seal, spot maybe shy so entice out in open, happy seal not have exit, be sure to use new grease on seal engagement or you could dishonor family,

                    Never smack seal with sharp objection, always caress seal when installations... "

                    Comment


                    • #11
                      Originally posted by A.K. Boomer View Post
                      "look for exit spot on air seal, spot maybe shy so entice out in open, happy seal not have exit, be sure to use new grease on seal engagement or you could dishonor family,

                      Never smack seal with sharp objection, always caress seal when installations... "
                      So you get it!

                      JCFX how did you get the seals out without removing part #5.
                      The shortest distance between two points is a circle of infinite diameter.

                      Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

                      Comment


                      • #12
                        Pulling in the seals went well, I reversed the threaded rod so that the jam nutted end was the driven side
                        inside the bore. Oiled the bore of the end cap and the seal and the bottom seal went in without a hitch,
                        the other seal was just just as easy.





                        Some notes :
                        I did this with the mill head tilted 90؛

                        Gear #58 in my previous post has to get past a bearing, the spline tube has some give when it's in the seals
                        I rocked it just enough to clear the bearing.

                        I buggered the original seals because I had the spline tube and gears already installed in the cover and could not see that the
                        assembly was cocked to one side, because of the aforementioned bearing clearance, caught the lip of the bottom seal and it was history.

                        2nd try, I have the spline tube already installed in the end cap it helps to look down the quill bore
                        to make sure the bottom seals lip isn't catching the end of the spline tube.

                        Fun part now is to see if the cover will go on while aligning four tight sliding fit items.

                        Comment


                        • #13
                          Originally posted by loose nut View Post
                          JCFX how did you get the seals out without removing part #5.
                          I used a flat head screw driver to deform the rim of the seal enough to yank the top one out out with needle nose piers
                          the bottom seal was harder, I used an awl to pick out some leverage of the seal rim for a flat screw driver and it was the same
                          as the top.

                          PS; The plastic wrap you see was there to catch the tool I made, I had to tap it out and didn't want it to hit the concrete floor since
                          it's a thin wall aluminum cup.
                          Last edited by jcfx; 07-12-2019, 09:51 PM.

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                          • #14
                            If the #5 part has to be removed to fix a leaky gasket then how is it put in with proper alignment. I don't see any type of pins or other devices to keep it centered.
                            The shortest distance between two points is a circle of infinite diameter.

                            Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

                            Comment


                            • #15
                              Originally posted by loose nut View Post
                              If the #5 part has to be removed to fix a leaky gasket then how is it put in with proper alignment. I don't see any type of pins or other devices to keep it centered.
                              That's the reason I opted to install the seals the way I did.

                              They made it, so there has to be factory trick on how they align that spline tube to the top cover bearing and spindle spline shaft.
                              I don't have to re do the RTV gasket on mine because the mill was bought a few months ago,
                              but I've thought about various theoretical ways to re do the gasket on #5 ( end cap ) if my need to do it arises,
                              they're in order of difficulty and accuracy -

                              1- Use the quill and spindle spline shaft as an alignment tool for the splined tube, lock the quill,
                              assemble the splined tube in the end cap with new seals, apply RTV to the clean mill surface,
                              slide the end cap splined tube assembly over the splined shaft and hope that it's aligned to a good degree.

                              2- In situ measure the quill bore, the flange and ID of the end cap and determine if there is enough material in the head to drill for alignment pins
                              on the end cap flange.

                              3- Use the spindle spline shaft as a key, machine two sleeves, sleeve #A slides over the 27.78 mm splined shaft, the OD of the sleeve #A is the bottom hole
                              of the end cap, the # B sleeve's OD is the ID of the end cap with a bore that fits the OD of the # A sleeve. Slide sleeve #A over the splined shaft, appy RTV
                              to the mill head, insert sleeve #B into the end cap and slide the unit onto #A.

                              4- Machine an alignment jig, the jig would be in three parts, top part A would be a snug slip fit sleeve to the bore ID of end cap sans the oil seals,
                              that is in turn bored to fit B.
                              B is machined to pass thru the hole at the bottom of the end cap, this is similar to theory # 3 above.
                              C is the exact OD of the quill, both parts B & C are drilled thru for a bolt to hold them together.
                              Part C would have to be at least 4" long, to prevent it rocking in the quill bore. Part C would go in the quill bore
                              and Part B would fastened to C, Part A the sleeve goes in the end cap and slides over B.
                              the end cap with the RTV applied on the mill head side would be slid over A and the screwed down.
                              Installing the seals would be as I did it, after the RTV has cured.

                              I hope the theories make sense, if anyone else has done this chime in.

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