Boring small holes smooth

  1. Brad93

    Brad93 M J B Engineering

    Messages:
    10,397
    Location:
    Essex
    Has anyone tried these miniature carbide boring bars? Similar to the Micro100 tools.

    I could of done with boring a 13mm hole out earlier, nice and smooth plain bearing finish but don’t have a 13mm reamer.

    £13 seems cheap enough.

    Second question. How on earth do you hold a boring bar this small.
     
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  2. pressbrake1

    pressbrake1 Forum Supporter

    Messages:
    2,884
    essex england
    To hold it put a block of steel in the tool post then use the lathe to drill and ream to suit . That will put it dead on centre height.
    To hold it pinch bolts or preferably split it so it clamps
     
  3. Seadog

    Seadog Forum Supporter

    Messages:
    6,973
    Location:
    NE London - UK
    It depends on the method you use to hold your other bars. A reducing sleeve would seem like the obvious way.
     
  4. northwest

    northwest Member

    Messages:
    2,061
    Location:
    Manchester UK
    Be very careful Brad, some of them have a lovely round shank (the Iscar ones) and others are oval and you need the dedicated holder.I have bought them in the past from a bloke called CNCpoorboy on ebay at a very good price. I just send him a message.
     
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  5. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    Often the shanks of these mini boring bars are not round so make sure any you buy are or if not you can get the appropriate holder.
    I have the WNT version of them and they are brilliant.

    ScreenHunter 536.jpg
     
  6. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    BTW that set pictured is about £110 plus VAT I think.
     
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  7. Screwdriver

    Screwdriver Forum Supporter

    Messages:
    6,900
    UK London
    If push comes to shove, weld/braze it onto a regular tool shank.
     
  8. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    Does carbide weld?
     
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  9. mtt.tr

    mtt.tr Member

    Messages:
    4,052
    Essex England
    Just to cause upset hss anyone?
     
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  10. slim_boy_fat

    slim_boy_fat Forum Supporter

    Collet chuck?
     
  11. mtt.tr

    mtt.tr Member

    Messages:
    4,052
    Essex England
    Super glue and duct tape
     
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  12. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    Lots of these are HSS, it is about the only HSS I use nowadays although I do have a DNMG HSS insert somewhere :)
     
  13. pressbrake1

    pressbrake1 Forum Supporter

    Messages:
    2,884
    essex england
    No hence use of sintering material
     
  14. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    Spoken like a true builder :D
     
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  15. mtt.tr

    mtt.tr Member

    Messages:
    4,052
    Essex England
    At heart im a man of hide glue
     
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  16. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    I had heard but was unsure if true.
     
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  17. mtt.tr

    mtt.tr Member

    Messages:
    4,052
    Essex England
    We all are, though some are made from straw?

    Anyhow builders use expanding foam
     
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  18. Hood

    Hood If it walks like a duck....

    Messages:
    12,584
    Location:
    Carnoustie, Scotland
    Just the more modern ones :)
     
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  19. Kram

    Kram Member

    Messages:
    1,783
    Location:
    Sussex
    For a 13mm hole, Id use an S07K-SCLCR06, they are cheap, ccmt06 inserts and a min hole size about 8mm.
    www.ebay.co.uk/itm/S07K-SCLCR06-7x125mm-Lathe-Internal-Boring-Bar-Turning-Tool-Holder-For-CCMT0602/293134555726

    PH Horn are the ones to avoid, unless you like the challenge of making holders :)

    [​IMG]

    Its quite a simple holder. 5mm hole, 2.5mm hole and mill between. The difficult bit is finding an extra long series 2.5mm endmill, and drill bit. I did chip the big one and needs regrinding :ashamed:

    They are excellent. HSS in that size flaps around like a spring this hardly moves.

    PH Horn inserts are always a funny shape that is difficult to make a holder for, and holders not cheap.
     
    Brad93 likes this.
  20. brightspark

    brightspark Member

    Messages:
    31,715
    Location:
    yarm stockton on tees
    you can braze it easily enough
     
    Pete. likes this.
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