MT3 tang types

  1. skotl

    skotl Forum Supporter

    Messages:
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    New lathe, MT3 not MT2 like the old one, so I need to get some new tools.

    My mill is MT3 so I thought "Done deal! I can swap tools over!" - apparently not.

    This is a live centre that I've just bought, and it fits fine:

    upload_2020-1-30_22-28-18.png

    But my chuck looks like this (not picture of actual chuck):

    upload_2020-1-30_22-30-1.png

    Is there a name for each type, so that I can avoid the second one?
     
  2. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Drawbar. MT2 is available in metric and imperial threads. I forget the sizes
     
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  3. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Arc traderoute sell threaded tangs so you can eject them from tailstocks etc
     
  4. eLuSiVeMiTe

    eLuSiVeMiTe Forum Supporter

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    Beat me to it.
     
  5. Hood

    Hood Forum Supporter

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    Drills etc tend to have tangs, centres don't, both will be fine :)
     
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  6. Hood

    Hood Forum Supporter

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    I am of course assuming you are meaning the chuck and centre in the lathe and not the mill?
     
  7. skotl

    skotl Forum Supporter

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    Location:
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    Thanks guys

    Indeed

    Exactly - that's where I started to get confused.

    ----

    Actually - I'm starting to doubt myself - I need to go back into the garage and photograph the kit that does fit the endstock, and the ones that don't.

    So ignore me for now until I figure that out :(
     
  8. Newlands Member

    Messages:
    142
    Location:
    Sussex, UK
    The live centre doesn’t need a tang as there is no force trying to make it spin in the tailstock, unlike a drill chuck or drill.
    A mill is different - it needs a drawbar to pull the tooling up into the taper and keep it there - if you’ve ever tried to mill with a pillar drill (!) the chuck usually falls out because a morse taper doesn’t handle side loads at all well.
     
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  9. eLuSiVeMiTe

    eLuSiVeMiTe Forum Supporter

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    Wonder how many lathe tailstock tapers actually have a socket for a tang.
    Afaik the tang is for ejection.
    Axial load will losen a tool from the taper but drilling should aid retention with the pressure. Assuming the taper is in good condition
     
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  10. m_c Member

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    Location:
    East Lothian
    Tangs are for easy removal using a wedge, and normally found on drills. The tangs purpose is only for removal. The taper should do all the locking, as if it doesn't, any high power drill will simply shear the tang off.

    Threaded MT tapers are mainly used on mills, where cutting forces could pull the taper apart, so they need retained with a drawbar, which also doubles up as a suitable drift for removal.

    For tail stock holding in most lathes, you normally need a blunt ended MT, as the tailstock screw usually acts as a removal tool when wound fully in. A tang reduces the useable tailstock travel, and a hollow MT taper can allow the tail stock screw to simply wind down into the holder and not eject it. Easy fix is to loctite a grub screw in the end of threaded MT taper.
     
  11. Newlands Member

    Messages:
    142
    Location:
    Sussex, UK
    Yes, the tang is for ejection, but it also stops the chuck rotating in the taper. Same applies for a pillar drill quill. My Harrison lathe tailstock certainly has a socket for a tang - I’ve always assumed that’s the norm, but I could be wrong of course.
     
  12. Seadog

    Seadog Forum Supporter

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    I've always wondered why centres do not have tangs or, at least, an extension. They're a bugger to remove from the tailstock quill.
     
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  13. eLuSiVeMiTe

    eLuSiVeMiTe Forum Supporter

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    If I'm using a drill to big for my taper I Chuck a lathe dog on the shank. That's the only occasion I've slipped. An inch drill 200mm deep was asking a lot from a 2mt
     
  14. Hood

    Hood Forum Supporter

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    Normally they are not a problem but I suppose it may depend on the method of ejecting the taper on the tailstock. Most are done by winding the quill fully in and the taper end will be ejected when it comes into contact with the screw end. Some I have seen have hollw screw shaft so that you can use an ejector rod through the screw, that type is usually on small bench type lathes. If however your tailstock requires you to extend and use a drift then a centre without a tang would be an issue, can't say I have seen that type though or at least I can't recall.
     
  15. Hopefuldave Intergalactic pot-mender

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    Then you're putting too much tailstock pressure on them ;)

    As said, Loctite in a grubscrew to hit the tailstock screw.

    Dave H. (the other one)
     
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  16. rikrobson

    rikrobson Member

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    Location:
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    the lathe tail stock should take a tanged morse taper. A morse tapered mill quill will, however probably have a draw bar.
     
  17. Wedg1e

    Wedg1e They call me Mr. Bodge-angles

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    Sorry, couldn't resist :D
     
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  18. northwest Member

    Messages:
    809
    Location:
    Manchester UK
    It should fit just fine, you might need to rotate it to fit.
     
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  19. scottmk1

    scottmk1 Forum Supporter

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    1,153
    Location:
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    As said above, the tang needs to locate into it's female counterpart inside the quill, so might just need to rotate it until it's lined up then it should go no problem.
     
  20. 123hotchef Member

    Messages:
    8,466
    Location:
    Kent
    Scot get some adaptor sleeves so u can use your MT2 tools in the MT3
     
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