Vacuum plate or tabs? High feed or 3flute slotting?
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    Default Vacuum plate or tabs? High feed or 3flute slotting?

    Have a medium sized order of thin plate parts to mill out of a larger sheet, 10 gauge (~0.130 or so) steel 1011 structural plate.
    I can screw the plates down reasonably well, there is enough material in between the parts to get screws in the right places with adequate clearance, but once the part profiles are 2d contour'd out they will be free floating and probably break stuff without tabs.

    So, how often does a vacuum plate come in handy for a job shop (looking at a pierson one) in your experiences, and is it better than filing off tabs on ~500 parts?

    About the tabs, using a corner radius endmill or a high feed mill to mill the contour (full slot) leaves the radius on the tab making it harder to remove than it should be, very unsightly. I suspect I'm going to use a 3 flute square coated endmill for steel to do the profile contours if tabbing is chosen.

    Any other thoughts on vacuum workholding, sheet metal, high feed mills, tabs, or life in general?

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    What's the stock face finish like of the sheet?
    Vac needs a niceish finish for the oring to work.
    What size is your part?
    Calc your holdown force as 15psi, so if the part is 3 square inches you only have 45lbs of force.
    If you want to high feed, I'd be using screws to secure and the vac fixture can have orings round the screw threads to keep in the sealing of the vacuum.
    Then rough profile with plus Z (so screws still securing) and then use a small dia cutter to finish profile/breakout so the forces are small and the vac should then hold okay

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    Quote Originally Posted by meowkat View Post
    Any other thoughts on vacuum workholding, sheet metal, high feed mills, tabs, or life in general?
    I don't have much to input as I've only used a vacuum plate once in my life (we have one at my shop, we just don't use it!), the dude above me posted some helpful stuff and three quarters of the technical jargon I'm using I can't translate from Swedish to English but:

    in case you don't know or haven't thought of it, remember to use conventional milling to break off the tabs. (I.e. you want to have them flying away from the mill when they get loose.)

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    Magnetic works better than vacuum for steel, 70+ psi vs 15 psi. I don't think vacuum is going to work for you, unless your parts are huge and you use down-cut end mills.

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    Quote Originally Posted by meowkat View Post
    Have a medium sized order of thin plate parts to mill out of a larger sheet, 10 gauge (~0.130 or so) steel 1011 structural plate.
    I can screw the plates down reasonably well, there is enough material in between the parts to get screws in the right places with adequate clearance, but once the part profiles are 2d contour'd out they will be free floating and probably break stuff without tabs.

    So, how often does a vacuum plate come in handy for a job shop (looking at a pierson one) in your experiences, and is it better than filing off tabs on ~500 parts?

    About the tabs, using a corner radius endmill or a high feed mill to mill the contour (full slot) leaves the radius on the tab making it harder to remove than it should be, very unsightly. I suspect I'm going to use a 3 flute square coated endmill for steel to do the profile contours if tabbing is chosen.

    Any other thoughts on vacuum workholding, sheet metal, high feed mills, tabs, or life in general?
    we do a ton of stuff on vacuum plates havent found a store bought one that would work yet. we make all our own to match the parts we are machining.

    Like david said magnets may work better or a fixture with some clamps. as steel sheet metal likes to slide easy on alum.

    with our knowing the size of your part and the size of the plate your putting on it is hard to determine if vacuum plate would be good or not for your situation.also wether you have any holes in the part or not for hold down screws.

    when we had our 70+ inch mill we held down sheets and cut tons of parts out of it using a vacuum plate both alum and steel plastic etc etc.on our 4020 fadal we do semi big sheets as well, I have a almost 30 x 60" plate I made just for long sheets when I didnt have a shear,now I just borrow a friends shear as its easier cause the machines are always tied up

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    Id stack about 10 at a time do them that way. Have the blanks sheared out rough and screw them to fixture if possible and cut around the outside.

    Or better yet sub them out to laser cutting shop if you have one close by.

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    Would you stack? Look on this Routing of Aluminum Sheets - CRENO Industry
    Regards Libor

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    All good advice, might try stacking them to save some time.

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    Have a few experiences. If you need help I will help you. Only you. This information is not public Regards Libor

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    There's no real reason to buy a vacuum plate, they're easy to make, but if you do, there's a guy on Ebay who sells pretty decent ones for very little money.

    I get a lot of use out of the one I made, but it's for keeping things flat, not really for clamping. My plate has a grid pattern of tapped holes and dowel pin holes. The dowel pins keep everything from shifting, the screws keep it from throwing, and the vacuum keeps it from bowing.

    If it's just profiles, though, with no secondary machining, just send it out to a laser.


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