Insert placing toolhead to avoid traditional support material

Discussion in 'Tool heads & ToolChanger' started by 1013D, Jan 17, 2020.

  1. 1013D

    1013D Member

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    I am looking to do some production 3D printing with the tool changer and I want to avoid the use of traditional extruded support material for an overhanging lip on the part. The idea is to instead use a tool head to drop in an insert (that will likely have PVA glue on top of it) that will be used as the support, and then the print continues over this insert. After everything is done, the inserts can be pulled out of the part by hand and re-used. This should save some time both in printing, and in support material removal (not to mention cost savings of not having to use up support material).

    Anyone have any ideas on the insert dropping system? The inserts I have in mind are rather thin (2mm thick, and about 40mm by 30mm) probably use fiberglass or perhaps even aluminum or steel plates.

    I am thinking of basically a magazine of these inserts in the tool head and they get slid out 1 at a time after insertion (kind of like a coin dispenser). Or perhaps using magnets to hold them and the tool head motion to release them. Or perhaps a servo to slide them out of a dispenser.

    Any thoughts? has this been done before?
     
  2. dc42

    dc42 Well-Known Member

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    How about a simple hopper to one side of the bed where you stack the inserts on top of each other, and a vacuum pickup tool to pick and place them? To allow for the height of the top insert in the hopper varying, the vacuum pickup could be on the end of a spring loaded plunger.
     
  3. John Meacham

    John Meacham Well-Known Member

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    I'd do something simpler assuming the print is removed by hand anyway as an insert can be set roughly on the bed at that point.

    Just have a dumb tool with nothing but a small vertical bit of metal in a plus shape, like a cookie cutter that just cuts your dough into 4 quadrants.

    Then have the machine bring the tool close to the bed and come in and shove the insert into position from 4 sides. The plus shape is so it can come at it from each corner catching and aligning the part.

    So you just have the person who prepares the bed for the next print stick the insert in some predefined spot plus or minus a few cm of position or degrees of misalignment sloppily. And then the machine comes in and does final positioning.
     
  4. Jai Stanley

    Jai Stanley Well-Known Member

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    Might be a good idea to print a small interface that clips to your support, locking it in XYZ. Very small amount of material used per print and would give the placement toolhead something to locate the support into. I guess this idea relies on the support being a 'from the bed' type of course.

    Just spitballing an idea.
     
  5. John Meacham

    John Meacham Well-Known Member

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    Actually, if just one support piece is needed and it can be manually set up between each print, you might as well just attach it to the toolhead to begin with. designing something that just has to let go of an item in the right spot/time is much easier than something that needs to both pick something up and set it down. An electro-permanent magnet maybe or just a servo and clip mechanism could be used to trigger the release. Or a spring loaded thing that lets loose when the support is pressed onto the bed so no electronics are needed at all in it.
     
  6. 1013D

    1013D Member

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    Some more design requirements:
    -Multiple support pieces needed, for multiple pieces being printed (lets say 6 for simplicity)
    -the support piece will be flanked on 3 sides by printed material when it is placed (so it can be pulled out by hand, after the print is done, leaving a slot feature)

    a Vacuum holder is what I was leaning towards too, (also magnetic could work) but I think it can be a simpler passive system, or perhaps a single servo "gripper" can be used. Since only 3 sides are flanked, the 4th side can have a tab sticking out that can be used to grip the insert (there is clearance around the rest of the 3D printed part for gripping).

    The stack of inserts can be kept on the side, in place of the wiper. in fact the height adjustable wiper assembly ( https://www.thingiverse.com/thing:3744969 ) can be modified to hold the stack and can adjust height as each insert is removed. This might be overkill though. a simpler spring loaded magazine could work too.

    Is there a simple vacuum powersource that can be used? I am familiar with getting vacuum from a compressed air source, but there must be something simpler

    another thought was the tool head holds the magazine of inserts. this would probably be the simplest.
     
  7. dc42

    dc42 Well-Known Member

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  8. 1013D

    1013D Member

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  9. dc42

    dc42 Well-Known Member

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