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Thread: Any ideas on tailstock alignment?

  1. #1
    Join Date
    Apr 2006
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    Escondido, CA
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    Any ideas on tailstock alignment?

    I am having a little problem with tailstock alignment on my Grizzly G0800. I have notified tech support and will keep on working with them. First time around they said there was no means of adjustment, but to check debris / cosmoline. After cleaning there was an improvement so I thought the problem was over. But there is still this misalignment. It only makes a difference on tall chalices when I am trying to keep the cup stable when turning the outside of the chalice.

    Any ideas here? I will definitely keep moving with Grizzly tech support.

    Here are pictures of the misalignment and the alignment plates on the bottom. When I loosen the 3 hex screws, the plate still seems immovable
    Attached Images Attached Images
    Veni Vidi Vendi Vente! I came, I saw, I bought a large coffee!

  2. Level your lathe bed front to back, side to side, diagonally in both directions.........99 times out of a hundred, it is one leg pushing on the ways more than the others. A small high spot on your concrete floor can exert just enough torque to affect alignment of centers. Loosen all feet, then do the level thing, working diagonally first.....this should take care of it... it is best to level with the headstock and tailstock off the ways.
    Remember, in a moments time, everything can change!

    Vision - not just seeing what is, but seeing what can be!




  3. #3
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    Feb 2012
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    Haubstadt (Evansville), Indiana
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    You are fairly close. Any chance you have another spur center? Just to verify I would change to a sour center and check. Then reverse them and re check. That will tell you it is the lathe for sure. That will take any problem with the centers out of the picture. I just never liked checking with a rotating center.
    When working I had more money than time. In retirement I have more time than money. Love the time, miss the money.

  4. #4
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    Apr 2006
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    This is why you all are miracle-workers. I had not thought of either issue. I can see that the lathe bed is just a little off-level. I will adjust that, but I am not nearly powerful enough to remove the headstock

    When I put a spur center in the tailstock, it was a much better alignment. That tells me the issue is the live center. I will ask grizzly for a replacement and/or buy another. If I buy another one, do you have any recommendations?
    Veni Vidi Vendi Vente! I came, I saw, I bought a large coffee!

  5. #5
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    Nov 2007
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    Brian, do you know what 'winding sticks' are? If not google them. Easy way to check for twist in the bed. Lyle Jameison has a good video on adjusting the feet. For the live center, Oneway, Robust, and Jet/Powermatic all make good ones - and all work with standard accessories.
    Retired - when every day is Saturday (unless it's Sunday).

  6. #6
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    Apr 2006
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    Yes, I have used winding sticks but not on this. Than you for your idea and for the live center recommendations.
    Veni Vidi Vendi Vente! I came, I saw, I bought a large coffee!

  7. #7
    Join Date
    Jan 2010
    Location
    Saturna Island, B.C.
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    if you want a true reading as to how true it is you will have to use a dial indicator.. put on about a 6" f/plate and mount the dial indicator on it with a magnetic base and set the t/stock back 10 or n12 inches and take a couple different readings with the d/indicator rotating( by Hand) around the quill and also something in the morse taper that you can read that will be true(like in the pic). you will not find many standards relating to what the tolerances are, but the are about .005" at about 12" away from the faceplate. these are actyall old US army specs. that I dug up about 35 years ago and still have somewhere.( pre internet research). my General was .090" when I got it and had a terrible battle with and ended up in small claims court and they allowed me $1,000.00 off the price to fix it. I finally got it down to .0015"

    ron

  8. #8
    Join Date
    Sep 2015
    Location
    San Diego, Ca
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    My Griz live centers are not very good. They only have a single bearing and they wobble a bit. I got one replacement and it was mismanufactured to the extent that it wouldn't turn. The next one was almost as sloppy as the first one. All three only had a single bearing. I would recommend getting a live center with at least a pair of bearings rather than just a single one. In fact, I saw one in some catalog or on-line that used three bearings. I suspect that it would be rock solid.

    Roger's advice was good. Another variation or approach if that normal leveling doesn't work would be to (everybody take a deep breath now) adjust the feet and watch the alignment as you adjust the legs - - intentionally adding a little twist until the alignment is perfect.

  9. #9
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    Jul 2008
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    Don’t be too quick to blame the tailstock Brian, the headstock could well be the culprit, or both the headstock and tailstock.

    Yes see if the bed is twisted, and correct that if it is, also move that headstock and see it that changes anything, just some dirt or wax under it will make a difference.

    Also clean de MT openings in both headstock and tailstock, and install quality centers and than see if you are still not aligned properly, BTW I did not see if the points are off horizontally (higher/lower) or vertically (left or right).
    Have fun and take care

  10. #10
    Join Date
    Feb 2008
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    E TN, near Knoxville
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    12,298

    Correcting misalignment

    Quote Originally Posted by Brian Kent View Post
    I am having a little problem with tailstock alignment on my Grizzly G0800. I have notified tech support and will keep on working with them. First time around they said there was no means of adjustment, but to check debris / cosmoline. After cleaning there was an improvement so I thought the problem was over. But there is still this misalignment. It only makes a difference on tall chalices when I am trying to keep the cup stable when turning the outside of the chalice.
    Any ideas here? I will definitely keep moving with Grizzly tech support.
    Here are pictures of the misalignment and the alignment plates on the bottom. When I loosen the 3 hex screws, the plate still seems immovable
    Brian.

    Did you try adjusting one of the legs? I didn't carefully read all the posts in this thread, but just in case: I have aligned lathes many times, most recently at a club demo where Mark St. Leger was turning on our Jet 1642. I never worry if the lathe is level, as in "perpendicular to the line to the center of the earth" - the lathe will work fine on a slight tilt. It does matter if the top is not all in one plane. (This is also true for table saws, etc.) Cast iron is actually quite flexible and the entire lathe bed will easily twist if one leg is too high or low. I read an account of a demonstration at a machine shop showing how the bed of a large metal-cutting lathe deflected by pushing in the center with a hand.

    To align, simply put points in both the headstock and tailstock, move them very close so they are almost touching, then crank on just one of the leg levelers. It doesn't even matter which leg to adjust but I usually crank on one at the tailstock end. In all cases, this brought the points into exact alignment. If the lathe doesn't have leveling feet, use a shim. BTW, this is an old, old established alignment method.

    I only care about the alignment when the tailstock is quite near the headstock where it can really mess up things. The further away from the headstock, the smaller the angle of any alignment error. A small misalignment will have no practical effect when turning a spindle between centers.

    In most cases the misalignment is horizontal and not vertical. If the misalignment is vertical and adjusting one leg doesn't fix it, there is probably a different problem such as a machining tolerance error or a burr. (I did discover once when swapping headstocks between two lathes of the same model that the machining appeared to be different between the two resulting in a misalignment. I didn't take the time to analyze it further, I just swapped the tailstocks too and got on with life.)

    JKJ

  11. #11
    Perhaps I missed it but I don't see whether or no you mention if your headstock can rotate or not? I recently purchased Teknatool's alignment tool to solve an alignment problem on my lathe...loosened both 'ends', inserted the alignment tool into both the head and tailstocks, tighten and your done. Good luck..

  12. Quote Originally Posted by Brian Kent View Post
    When I put a spur center in the tailstock, it was a much better alignment. That tells me the issue is the live center. I will ask grizzly for a replacement and/or buy another. If I buy another one, do you have any recommendations?
    My live center that came with my G0766 is just fine. I do have a Oneway live center that I purchased from another turner, who got a new Oneway lathe....he already had a Oneway center, so sold me the new one. I use it most of the time, but I also use the Grizzly live center as well. I have had no problems with mine. I would highly recommend the Oneway live center.......good stuff.
    Remember, in a moments time, everything can change!

    Vision - not just seeing what is, but seeing what can be!




  13. #13
    Sounds like you are getting great advice. I too received a bad live center, the replacement was much better. I use a oneway live center normally, love it, and also have a live jacobs chuck too.

  14. #14
    Join Date
    Jul 2008
    Location
    Atikokan, Rainy River district, Ontario
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    3,540
    Quote Originally Posted by Brian Kent View Post
    I am having a little problem with tailstock alignment on my Grizzly G0800. I have notified tech support and will keep on working with them. First time around they said there was no means of adjustment, but to check debris / cosmoline. After cleaning there was an improvement so I thought the problem was over. But there is still this misalignment. It only makes a difference on tall chalices when I am trying to keep the cup stable when turning the outside of the chalice.

    Any ideas here? I will definitely keep moving with Grizzly tech support.

    Here are pictures of the misalignment and the alignment plates on the bottom. When I loosen the 3 hex screws, the plate still seems immovable


    About the plate under the tailstock, I looks like the screws hold it against the bottom and it is pinned there, meaning the pins hold it in place so it will not be able to move, something the screws would not be able to do.

    Loosening the screws will therefore not let you move the plate, you would have to remove the pins, something I would not recommend you do.
    Have fun and take care

  15. #15
    Join Date
    May 2003
    Location
    NW Arkansas
    Posts
    180
    Another possibility. The tail stock may have been bored cockeyed for the quill. To check match centers with the tail stock quill retracted completely. Next extend the quill completely and match centers again. If they are different the tail stock is suspect. Also make sure the quill is locked tight before matching centers.

    I find it hard to believe there is much error in the centers. A level bed on a lathe is very important, but most of the time the error would be measured in the thousandths.
    Larry

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