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  • Mini Lathe Tailstock Alignment

    Hello,

    I recently bought a mini lathe 7x14" (180x350mm) for my workshop and I have to say that I should have bought a lathe it much earlier.
    The machine is a small China import lathe (nothing special) with 550 Watts motor and metal gears and as you can tell I am really excited about it.

    The only problem I found so far is that the tailstock is not very accurately aligned with the headstock center.
    As I am new to lathes I searched on YouTube and I found 2 or 3 ways, using a dial indicator, to align it but my lack of experience does not allow me to fix my problem...

    After a small online research I found out a tailstock alignment tool called MT2 to MT3 Buddy Bar. This "Buddy Bar" has one end MT2 Morse Tapered and the other end MT3 Morse Tapered.
    The MT2 end fits into the tailstock and the MT3 end fits into the headstock and that "fitting" makes the alignment.

    Do you think that this tool does cover my need?
    Is it as easy as it sounds or I will have issues?

    Thank you very much
    Nikos
    SourceRabbit - Desktop CNC Milling Machines

  • #2
    Do you have a set-over tailstock? If so, that tool might be useful if you plan on changing the alignment regularly. Otherwise, you can use a piece of card pinched gently between centers to roughly judge alignment, then fine tune it by making test cuts between centers on a piece of thick stock and measuring the amount of taper along the cut.
    Max
    http://joyofprecision.com/

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    • #3
      I'm assuming that the tailstock will need shimming and re-tightening to get it to hold that position- the challenge will be to make sure it's still aligned once it's tightened down. I like the idea though- and presumably you would carefully check to see that the exposed MT2 part rotates precisely on axis without wobble beforehand. You would also need to know that the head stock is aligned previous to aligning the tail stock.

      I have thought of using such a device, but I also thought that a good way to maintain the alignment would be to use a filler of some kind between the base of the tail stock and the upper part. You would lay on the filler, then bed the tail stock upper onto it, then carefully squeegie out the excess filler while aligning with the jig. Once the filler is hardened you can add the hold-down bolts or whatever it uses, and it won't shift out of position.
      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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      • #4
        I turned a "flat" on two morse taper to jacobs drill chuck adapters. With the flat being the SAME EXACT diameter. So you put one in the headstock, one in the tailstock, then run a indicator between them.

        Its the same as having a test bar between centers but you can move the tailstock back and forth.... I will post pictures if needed.
        Feel free to put me on ignore....

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        • #5
          One of the chores with tail stock alignment is getting the bore aligned in all three axes. The buddy bar seems excellent for that. It's nice to be able to run the tail stock spindle in and out without losing alignment.
          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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          • #6
            Normally, the headstock should be shimmed to match the height of the tailstock, however, the OP doesn't say which way the tailstock is out of alignment.

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            • #7
              Seems like a bad idea as it will be too rigid and trying to force the tailstock into place but it will spring back after removal. The starting point is to put a soft centre into the headstock and skim it as it turns so it must be dead true. ( you can also just put a bit of bar in the 3jaw and turn it to a point) Then put a good clean sharp hard centre in the tailstock not one that came out of the rusty bin at a yard sale and gently bring them almost together. this will show you coarse alignment which you can improve. Then you gently bring them together with a thin flat shim in between like a razor blade. Any miss-alignment twists the blade. You will understand as you try it. You seldom need better alignment than this and since things can move over time when you do need real good alignment use improved methods.
              If you can post a link to a picture of the lathe or equivalent we will have a better idea of what the options are and perhaps people with the same one will recognise it.

              Comment


              • #8
                Hi Nikos,
                You do not say whether you have a Sieg or a Real Bull minilathe.. The tailstocks are quite different for the two lathes.
                I have a Sieg lathe and I made a number of modifications to the tailstock to permit alignment. If you are interested then see:
                http://mikesworkshop.weebly.com/tail...fications.html
                Mike

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                • #9
                  Hello guys!

                  Thank you all for your tips!

                  I will post a few photos of my lathe later so you can see it

                  @mars-red I am not planning to change the alignment regularly but who knows in the future.

                  @Baz I tried something like that but.... I will do it again

                  @drmico60 My tailstock is simular to Sieg. As I can see Real Bull is better...
                  SourceRabbit - Desktop CNC Milling Machines

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                  • #10
                    Hello again,

                    I am posting a few photos of the mini lathe and the kind of alignment I did...

                    This is the mini lathe 7x14" (180x350mm)


                    This is my alignment way...
                    I inserted a linear bearing shaft in the headstock chuck then I inserted it in the tailstock chuck and then I inserted the tailstock in the tailstock chuck morse tapered shaft...


                    And the results!
                    I tested the tailstock shaft from one side to the other with the dial indicator and I found that the difference is less than 0.05mm.
                    Does this mean that I am parallel to the lathe ways ?




                    Thank you
                    Nikos
                    Last edited by rabbit_nick; 01-02-2016, 09:37 AM.
                    SourceRabbit - Desktop CNC Milling Machines

                    Comment


                    • #11
                      I agree with Baz as this is the easiest way I have found to check alignment as well. Unless you want to really get cared away it works well and is simple to do. To me easy is always better. !!
                      John From Slinger, Wisconsin

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                      • #12
                        I think Baz solution is good but I am a newbie so I dont know if I am going to do it right but I will try
                        SourceRabbit - Desktop CNC Milling Machines

                        Comment


                        • #13
                          Welcome to the site Rabbit.

                          You are not really doing it right. Here's why Baz's suggestion is more valid.

                          First; some facts;
                          1) The 3 jaw chuck is not very accurate. It may be off by several thousandths of an inch.
                          2) A drill chuck is extremely inaccurate. It may be off by 10 thousandths of an inch or more.
                          2a) The rods you are using are not necessarily straight and consistent diameter.

                          3) If you stick a bar of aluminum in the 3 jaw chuck and then use the lathe to make a point on the end, the point will be centered in the exact center of the chuck's rotation (also known as the lathe's axis).
                          4) If you stick a short, stiff drill in the tailstock and drill into the end of an aluminum bar, the hole may be oversize, but it will be centered with regard to the lathe's axis.
                          5) What you want is for the tailstock to be at the same height as the lathe's axis, parallel to the axis and lined up with the axis front to back. In other words, lined up in both dimensions as well as parallel.

                          Using Baz's suggestion will give you two known good points (the pointed rod in the chuck and the pointed center in the tailstock) to compare. Anything pinched between the two points will tilt if the points are not perfectly aligned. A razor blade is often used for this.

                          When you have the points aligned, then you move the tailstock and extend the ram an inch or two. If they are still aligned, the tailstock bore is parallel with the axis in all directions.

                          The real test is to make two test cuts on opposite ends of a 6 inch bar that is mounted between centers. The diameter of the test cuts will be the same if everything is aligned.

                          Dan
                          ( yeah, I realize that now you have to look up terms like "mounted between centers", but machining is an endeavor that is benefits from doing a lot of reading as well as watching videos. The more you know, the easier it is to use the tools)
                          At the end of the project, there is a profound difference between spare parts and extra parts.

                          Location: SF East Bay.

                          Comment


                          • #14
                            Hi Dan,

                            I will try to make a pointed center and do the Baz way. I also saw it on a youtube video so I think I know what to do (short of...)


                            Thank you
                            Nikos

                            PS. I know what "mounted between centers" and "turning between centers" is
                            SourceRabbit - Desktop CNC Milling Machines

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                            • #15
                              I found that the flat setscrews that lock the tailstock don't really grip very well and the tailstock can shift. I replaced mine with cup points.

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