LEAVE THEM HANGING,parting on the lathe
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    Default LEAVE THEM HANGING,parting on the lathe

    Since 1976 ,I have made thousands of DIFFERENT parts on NC lathes in tool and die shops.Most parts are nasty tool steel,prehard 4140,h13 d2 ect.Not production quantities ,usually 1 to 10 parts.. I found that damage to the parting tool usually happens when the part comes free and the part goes flying.SOO,I allways program the parting tool to rapid retract when it reaches .150 diameter.The lathe stops and the part is left hanging. I can wiggle the part back and forth and it breaks off.For long parts ,I increase the diameter. If I miscalculate and the part wont break off easily, a few strokes with a good hacksaw ,weekens the nub and the part break off. OH YEA,this also keeps the part from getting banged up when it goes flying.This also works when faceing.The hardest thing on carbide is cutting on center. You have almost zero surface feet per minute and you are bulldozing the nub at center.If you leave the nub,you can easily remove it and make a beautiful part with a 2 inch air sander with the spindle turning about 300 rpm. Of course this means reaching in and running the spindle with the door open. Edwin Dirnbeck

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    I don't understand the purpose of this thread. Are you answering someone's question or are you just giving a QOL tip?

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    That procedure also works good on very small plastic parts that will get lost in the chips if fully parted. With the small PEEK parts that we call mouse droppings stopping about .015 shy of cutting off works, break the part off and press cycle start again to finish cutting off the nub. Cycle repeat will take it past the M02 cycle stop so in practice the lathe only stops once.

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    Quote Originally Posted by Mtndew View Post
    I don't understand the purpose of this thread. Are you answering someone's question or are you just giving a QOL tip?
    Well it is definitely not a qol tip,because ,I don't know what that is.This is A lathe procedure that has worked for me.I think others might not know this,and it would be helpful.Edwin Dirnbeck

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    Quote Originally Posted by edwin dirnbeck View Post
    Well it is definitely not a qol tip,because ,I don't know what that is.This is A lathe procedure that has worked for me.I think others might not know this,and it would be helpful.Edwin Dirnbeck
    QOL = quality of life.

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    I have always done this running manual machines also. Wouldn't help much for lights-out though. For that maybe you could add a tool holder with a spring loaded hacksaw blade and program it to cut the part off with back and forth strokes?

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    I do the same thing, but use a stubby flat screwdriver in the gap to pop them off, my parts don't weigh that much.

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    Kinda puts an end to "lights out un-attended operation" that CNC machine is for eh ?....

    Or just doo like been done for 50 years on automatics, place the cut off
    tool on top.....

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    Quote Originally Posted by edwin dirnbeck View Post
    If you leave the nub,you can easily remove it and make a beautiful part with a 2 inch air sander with the spindle turning about 300 rpm. Of course this means reaching in and running the spindle with the door open. Edwin Dirnbeck

    Won't catch me or any of my employees using an abrasive tool inside a lathe enclosure....Lathe way wipers not designed to exclude fine grit....Good way to kill a machine.
    Cheers Ross

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    Quote Originally Posted by AlfaGTA View Post
    Won't catch me or any of my employees using an abrasive tool inside a lathe enclosure....Lathe way wipers not designed to exclude fine grit....Good way to kill a machine.
    Cheers Ross
    Could do what I do, pause the machine break the part off and press cycle start to restart the spindle and finish cutting off or bring another tool up and face it off.

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    Quote Originally Posted by AlfaGTA View Post
    Won't catch me or any of my employees using an abrasive tool inside a lathe enclosure....Lathe way wipers not designed to exclude fine grit....Good way to kill a machine.
    Cheers Ross
    No abrasive needed....No dangerous chuck spinning while the door is open:

    4 lb. Hardwood Engineer'''s Hammer
    Attached Thumbnails Attached Thumbnails 69240_w3.jpg  

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    Quote Originally Posted by camscan View Post
    Digger,is that a carbide or HSS part off tool?
    "Chineesium"...with a touch of imported ash.

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    Quote Originally Posted by digger doug View Post
    Kinda puts an end to "lights out un-attended operation" that CNC machine is for eh ?....

    Or just doo like been done for 50 years on automatics, place the cut off
    tool on top.....
    As I stated in my OP ,mostly 1 or 2 parts for tooling. No such thing as lights out production. We use the NC to routinely generate complex shapes thst use to be very tedious. Also ,when parting off tough tool steel,it doesn't matter if the tool is on top ,bottom or in between,the part pops off and the last bit of nub destroys your insert. Edwin Dirnbeck

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    Quote Originally Posted by edwin dirnbeck View Post
    As I stated in my OP ,mostly 1 or 2 parts for tooling. No such thing as lights out production. We use the NC to routinely generate complex shapes thst use to be very tedious. Also ,when parting off tough tool steel,it doesn't matter if the tool is on top ,bottom or in between,the part pops off and the last bit of nub destroys your insert. Edwin Dirnbeck
    The last bit of nub destroys your tool ?

    I'm sorry to hear that.

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    Or you could just make sure the tool is dead on center and just part the parts off and let them drop in the parts catcher. It is not rocket science.

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    Happened to me more than once. I stopped buying expensive parting tools and keep a hack saw close by.

    dsc_0899.jpg


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