Ideas for measuring real time tombstone deflection in a Mazak pallet tech
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    Default Ideas for measuring real time tombstone deflection in a Mazak pallet tech

    I知 looking for ideas on how to settle an argument about deflection.

    I知 trying to find coolant proof drop indicators that will record movement while machine is cutting. Or any low cost but workable ideas to quantify movement of pallet caused by tool pressure and cutting forces.

    My issues are that it is a horizontal mill and the pallet moves in the z direction while cutting. Lots of arguments about the tombstone flexing or lifting. All speculation no data collected. I can not operate the machine with the door open.

    I understand that I知 not giving much details. Any help is appreciated.

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    Quote Originally Posted by karl kunkle View Post
    I’m looking for ideas on how to settle an argument about deflection.

    I’m trying to find coolant proof drop indicators that will record movement while machine is cutting. Or any low cost but workable ideas to quantify movement of pallet caused by tool pressure and cutting forces.

    My issues are that it is a horizontal mill and the pallet moves in the z direction while cutting. Lots of arguments about the tombstone flexing or lifting. All speculation no data collected. I can not operate the machine with the door open.

    I understand that I’m not giving much details. Any help is appreciated.
    .
    usually if you mount indicator or mount a precision electronic level when cutting the vibration is too severe to get a good reading. at least thats been my experience
    .
    some pallets and rotary tables need a gcode to clamp holddown and clamp table rotation. assuming its working as its suppose too. if chips under table or pallet it might not be down all the way
    .
    many cnc if reads table rotated .001 degree( from heavy cutting forces) will stop with error message. obviously if it doesnt stop with error message that can be a problem

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    I don't know Mazak, but most pallets have a long dimension and a short dimension on the locator pads. The pallets tip much easier across the short dimension. Can you change your machining to the pallet face that has the longer dimension from the locator pads and compare the machining results?

    Other thoughts if you have load indicators on your Z axis. With the spindle off, bring a blank toolholder against the pallet at the maximum height of machining. Measure the lift of the pallet between the pallet and the receiver.

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    Air gauging works in lousy environments because it blows away coolant and chips and the readout is outside the machine.

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    You would need, ideally four LVDT's and readers. One affixed under each side or corner of the pallet to the machine frame as the reference. This will not detect the frame deformation only the relative deformation between the frame and the pallet base. You have no fixed reference at the top of the pallet with which to mount a measuring device. The four let you see lift and compression. These are available sealed so will last some time in a coolant environment.

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    Quote Originally Posted by Tonytn36 View Post
    You would need, ideally four LVDT's and readers. One affixed under each side or corner of the pallet to the machine frame as the reference. This will not detect the frame deformation only the relative deformation between the frame and the pallet base. You have no fixed reference at the top of the pallet with which to mount a measuring device. The four let you see lift and compression. These are available sealed so will last some time in a coolant environment.
    Yup, and you would need something inside the tombstone at bottom & top
    to measure actual tombstone bending.

    IIRC reading various older machinery magazines, the main american machine
    builders would outfit machine tools in the lab to such things.


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