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IndustryArena Forum > MetalWorking Machines > Okuma > LB15 Whacked chuck and all Tools are above center.
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  1. #1

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    Mar 2022
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    LB15 Whacked chuck and all Tools are above center.

    Crashed parting tool into chuck on my LB15 all tools in turret are now above center. The guy I would normally use has retired. Can anybody help with this issue? Thanks.

  2. #2
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    Re: LB15 Whacked chuck and all Tools are above center.

    Single block on , feedrate down, confirm distance to go = never crash.

    Your turret is rotationally off. You will need to remove the front turret plate, loosen turret to curvic coupling bolts, pull 2 taper pins (if there), align parallel to X axis movement by indicating turret slot as you use precision alignment tool (dead blow hammer) to tap back into alignment. Tighten down. Check Z for parallelism to turret and headstock for taper as well in Z. After finishing, use ID toolholder to find out how much you are off in X. (X0 is center of ID block) Whatever you are off, add/sub to the amount in PR ZERO OFFSET in your system parameters. Re-boot and re-check X0 to confirm it is still at 0 and position reads 0.

    Good luck!
    Experience is what you get just after you needed it.

  3. #3
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    Re: LB15 Whacked chuck and all Tools are above center.

    hy what mr wizard described is el-clasico, the way to go

    most setups don't use entire turret capacity, and even if it would, only a few are required to reach spindle center:
    ... od tools : shims only on those critical tools, that may be only 2 or 3
    ... id tools : rotate them a bit; you would normally do this even on a good turret, thus i refer only to those tools that are small; rest of them can take it
    ... driling tools : you need excentric sleeves, or y
    list goes on; in the end, you start up faster after a crash, with much less strain; such tricks save time and $

    turets that i setup are missaligned from a few years ago, and they are comonly getting hit because of whatever reason ( last one was previous weekend ); worst lathe status that i setup was turret Z0.5 X1.7 Y-0.7 and spindle 0.15/200, for a few months, including deep drilling

    if you know what to do, a lathe can go on if it had been kicked, while a mill can not as easy ...

    the key is to know what tolerance you need, and how to reach it fast, and trust/understand the measuring methods accuracy; for example, there is a tendency to align too much towards 0, in a world where axis positioning repetability, tooling mount repetability, and others, all those summed up lead to variations

    y turrets help a lot, and last lathes where ordered such way, not because y is used as much for machining, but as a helper for alingments, including long tools, or turet rotation after crash / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  4. #4
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    Re: LB15 Whacked chuck and all Tools are above center.

    hello this is a short brief for continuing operation on missaligned lathes, thus no need to proceed with full re-alignment, but target only toolholders of interest

    [ example 1 ] : center drilling / s axis ( spindle and turret geometry shifted )

    pls check attached : adjustemtn will be easier on lathes with tilted casts, because active tuuret post plane is perpendicular on cast grinded plane, thus toolholder rotation after shim, can follow spindle missalignment pretty accurate; for those with planar casts, is needed a tolerate approach, that can work when holes are not so deep, because :
    ... even if the drill is mounted tilted, it can still work fine with short parts, thus it won't deliver a hole as long as it's active length
    ... u drills can tolerate missalingment way better than carbide drills
    ... carbide drills are conical, thus nominal dimension is only at their top; you can compare tool conicity with machine misslignment, and try to adjust the toolhoder at least until deviation between tool axis and s axis is withing tool conicity

    [ example 2 ] : radial drilling / m axis ( only for vdi misslainged turrets, it wont work for bmt )

    bmt toolholder mounting consistency is >> vdi, so use the less consistency of the vdi to your advantage during mounting, force the toolholder to rotate, then dial it so to detect its angle, then compare to x axis; it is not critical to align it perfectly to x axis, just rotate it towards the direction that helps

    after that, think tolerances, like, for example, is possible to use a carbide o12 drill for 50mm depth, with a misslaingment of 0.15/100; even on a straight turret, the drill would have bent and go a little on side when exiting; after o14, M axis coupling fails anyway, so ...

    [ example 3, theoreticall ] : you can use a wnmg insert as long as turret rotation in xz plane is <5degrees; if it is bigger, then rotate the tool



    such adjustments may require to :
    ... use x<>0 and/or y<>0 on operations that normally would require x0 y0; but such things are used even on aligned lathes for deep drilling, small tool adjustment, etc
    ... skew the toolpaths, especially when x is no longer perpendicular on s, as when z is no longer paralel to s; but, again, such things are used even on aligned lathes, to adjust long diameter conicity when using the tailstock, or for big flanges to avoid face conicity, etc

    so, is possible to reduce downtime & stress associated with crashes, and postpone alignment as looooooooong as possible

    misslaingments do not occur only because of operator error

    may seem a bit complicated, but with repetition, is all ok, you will know where to look and what to do pretty fast / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  5. #5

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    Re: LB15 Whacked chuck and all Tools are above center.

    Finally got some time to work on this. Covers off bolts are loose, taper pins pulled. Do I put a bar in the tool slot and hit the bar to shift turret or? Also where do i mount indicator to tram X turret slot? Thanks.

  6. #6
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    Re: LB15 Whacked chuck and all Tools are above center.

    Mount your dial indicator in a solid block gripped in the chuck.
    Do NOT use just a magnetic base as they can, and usually do, move!
    Holding the dial guage in the chuck gives you good repeatability when sweeping the ID hole, use a mirror to see the face of the dial guage, unless you like being a bat and swinging around upside down to see it
    You can then also tram along the X Axis to make sure the Turret is rotationaly aligned.
    With your coupling bolts loose, a dead blow hammer should be all you need to tap the turret around to get it in position.
    Gently nip your turret down and constantly check it hasn't moved as you tighten it down.
    Once you get the tool holder slot Zero along X, then sweep your ID holder to get X0,
    Obviously, to get X0 correct at 90° to X, you will need to adjust the tool holder vertically on the face of the turret, usually the "dowel" is eccentric, so making the adjustment fairly easy, just time consuming as you have to remove the tool holder to make the adjustment.
    Make sure you tram the tool holder pot along Z to make sure it is not pointing up or down.
    If it is not level along Z, when you have a long tool in the machine it is going to way out at the end of the tool.
    First time you do this alignment can take ages, but should you be unfortunate to need to do this again, it will be much easier.
    Cheers
    Brian.

  7. #7
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    Re: LB15 Whacked chuck and all Tools are above center.

    hy pls share photo with turret

    is there c or y axis ? kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  8. #8
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    Re: LB15 Whacked chuck and all Tools are above center.

    Quote Originally Posted by deadlykitten View Post
    hy pls share photo with turret

    is there c or y axis ? kindly
    LB15 model is a very old model... probably around the 1980's or 90's
    At most it may have a M spindle but that would be it.

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