Dumb question, but here I go. Can I mill depths deeper than my flute length?
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    Default Dumb question, but here I go. Can I mill depths deeper than my flute length?

    Hi there;
    I have been scared to cut slots deeper than my flute length, even though shank and flute are the same diameter...
    The obvious problem is chip evacuation...
    But, is it true I can't bury the flutes?
    I mean, I won't D.O.C. beyond one diameter.. but wondering if I will get away with it, or kill end mills.
    Thanks,
    Mark

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    You will get some burning above the flutes if you are running deeper than the flute length. While the shank is technically the same diameter as the flutes (except reduced-shank or necked endmills), the tool is not cutting EXACTLY at the diameter of the flutes. Just a bit under, but just a bit under is enough to allow the shank to rub.

    Sometimes you can go a LITTLE deeper, like .03" or so, as the flutes don't just suddenly stop right at the nominal flute length.

    Regards.

    Mike

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    Quote Originally Posted by snowshooze View Post
    I mean, I won't D.O.C. beyond one diameter.. but wondering if I will get away with it, or kill end mills.
    Huh? Which DOC are you talking about? Most endmills have flute lengths that are like 2x or 3x the diameter.

    I think one of us is confused.

    Regards.

    Mike

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    What he/she said is clear.

    Your stepdown is one thing and total depth is another as you know.

    You can go past your flute length in total depth but you will rub the shank of the tool. You can buy or have made relieved neck tools to do as your wanting.

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    Oh, just go to the surface grinder with the spin-jig and skinney it up?
    Thanks,
    Mark

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    Rule of thumb here is 1/2 diameter.
    I violate that occasionally, at the expense of chip-load.

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    Well, that part isn't at issue.
    I step down generally around 1/2 diamter.
    If I do that enough, I run outta flutes.

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    If this is a one-off or a two-see or three-see, I say go for it. With careful steps and clean out the chips after each pass.

    If this is a production situation and many parts must be cut, then just break down and buy a couple of longer end mills.

    As for the rubbing thing, use a good cutting fluid; one with good lubrication properties.

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    Will, cutting a production fixture.
    .375" Mill, .3967" Slots, but .500" deeper than flutes.
    78 slots, 1.375" long, 1.5 deep. 6061.
    Blaser 755

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    Quote Originally Posted by snowshooze View Post
    Will, cutting a production fixture.
    .375" Mill, .3967" Slots, but .500" deeper than flutes.
    78 slots, 1.375" long, 1.5 deep. 6061.
    Blaser 755
    Just buy the right tooling




    Sent from my Pixel 3 using Tapatalk

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    I would just grind a little off the shank.

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    30 seconds on a bench grinder, it doesnt need to be smooth or concentric, only smaller.

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    If you feed successive passes in opposite directions, cutter deflection will create a slot slightly wider than the cutter.

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    Series Display - M.A. Ford

    3/8" Endmill, 1.5" flute length... Cheaper than you think.

    4 Flute, Corner Radius - Variable Pitch, Reduced Neck price right on the website... About $100 depending on what you pick.

    Call these guys, tell them you want this endmill, but with a reduced neck, they'll likely modify it for you at no, or minimal charge. Less than $50. S42-003 – MITGI

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    I have done it a few times in a pinch. Yes you can buy the proper mill but not on a Saturday night when the job needs to be done by Monday morning. What I have done is is clamp a course diamond file in the mill vise. Bring the mill in the mill holder up to the file and run it up and down a few times with the Y feed. Take a few thousandths off the shank and it will not rub.

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    A reduced shank will be stiffer than more flute length so you might actually get more speed and a better finish.

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    These would work well for you but you would want to make sure you have the right sized collet for the shank.

    Reduced Shank 3/8 Variable flute X .359 shank X 3.5 long .010 Radius - Made in U MariTool

    Or this for 2x as much but uses a more standard size collet.

    http://www.harveytool.com/ToolTechIn...mber=943224-C3


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