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IndustryArena Forum > MetalWorking Machines > Okuma > please, how to improve coaxiality when drilling on a lathe ?
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  1. #1
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    please, how to improve coaxiality when drilling on a lathe ?

    hello guys ( and girls ) if inside each post of a turret is a drill, each post will output a different hole size ( chuck rotates, no live tool, no Y axis )

    1) turret radial play shoud be < 0.03
    2) holder bore dia is H7
    3) holder bore position should be <0.03
    4) sleeve used has h7 external dia
    5) sleeve used has H7 internal dia
    6) sleeve concentricity & coaxiality between OD&ID is ...
    7) maybe a collet is used to clamp the drill

    drill is manufactured in h7 tolerance, while 1+2+3+4+5+6+7 will sum some errors



    let's go to a real example : hole o15 is required; standard tolerance is ±0.1; hole size is o15.07; if i put the holder+tool on another post, i get o15.13

    the difference is not big, but please, how would you handle such cases ? what would you do, so to get a hole size as close to drill diameter as possible ? kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  2. #2
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    Re: please, how to improve coaxiality when drilling on a lathe ?


  3. #3
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    a drill inside a floating chuck / you have some sense of humor
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  4. #4
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    This isn't floating, this is adjustable

    Inviato dal mio LG-H850 utilizzando Tapatalk

  5. #5
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    ooook please, do you have a video / technical book / something for it ? only by looking at the link, is hard to guess what kind of adjusment it has ...

    i found this description : https://www.iscar.com/eCatalog/MoreI...8&item=4500404
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  6. #6
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    it has 1degree angular adjustement; at this value, it can compensate a turret Z missalignment of 1.745mm/100mm

    nice, thx okuma i will go for a quote ...


    also just found these : https://www.iscar.com/eCatalog/Produ...mapp=IT&app=98
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  7. #7
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    We use these
    https://www.iscar.com/eCatalog/Famil...pp=98&GFSTYP=M

    Inviato dal mio LG-H850 utilizzando Tapatalk

  8. #8
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    hi, that one seems to have 0.2mm radial adjustment

    i was thinking about this one, with 2mm rad adj : https://www.iscar.com/eCatalog/Famil...pp=98&GFSTYP=M

    also the L dimension is shorter; do you think that is better do have a shorter L ? i mean is there a compromise, comparing to yours ?

    and more questions please :
    ... how do you align those ? you use a centro inside the chuck ?
    ... is the radial adjustment 360 degrees ? or is it only among Y ?
    ... also, is the angular adjustment 360 degrees ? like anywhere on the surface of a cone ? or is it only among X ( so to compensate turret Z missalingment )

    thank you
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  9. #9
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    about gyro alignment i found attached pdf page, from here : https://www.tungaloy.com/wp-content/uploads/389.pdf

    alignment seems to involve :
    ... turning something in h5/h7, until the "guide bush" slides smooth
    ... insert a "pin" into the gyro
    ... gentle rotate the screws, until the "pin" slides smooth into the "guide bush"

    this may be a standard procedure, but is long, complicated and loses precision i wont go into such details right now, but there should be a faster way to do it

    however, even so, through the flange, there are M6 or M8 screws ( attached image ), and when the tool will be changed, the torque effort for clamping/unclamping the nut will pass through those tiny screws

    this is not stable; such a device should be :
    ... rigid enough to handle higher torque and shocks, or
    ... less rigid, while tool change procedure should require less torque

    in most cases, forces required to change a tool are greater than the cutting forces
    ... pro example : integral drills clamped inside a collet
    ... contra example : drills with inserts

    so i find this to be more reliable ( because a hydra holder requires less torque to change a tool, comparing to er chucks ) : https://www.iscar.com/eCatalog/Famil...pp=98&GFSTYP=M
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  10. #10
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    Re: please, how to improve coaxiality when drilling on a lathe ?

    hello all, if you wish, please check also these items :

    ... Dial-Ables – The Answer for Lathe Turret Misalignment ( it is similar to the gyro solution, shared by okuma85 in this thread; i don't like the setup procedure, seems long to me, and the device is not for high cutting forces )

    ... attached image + pdf ( setup procedure is shorter then the gyro, but also this device is for low cutting forces; you can find the full document here : http://www.everede.net/documents/201...ct_catalog.pdf , more infos here index.html )


    i will share soon infos about achieving coaxiality, faster, for operations with higher cutting forces / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

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