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    *Caldwell, Larry

    Unconstrained part won't insert

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    54 Views, 6 Replies
    11-30-2002 11:17 PM
    First time I've seen this. In CF there's am
    assembly with two cylinders and two risers. One fits up nicely, the other is a
    different story. If anyone would like to give it a try, see if you
    can insert the Riser into the Clevis. The Riser is unconstrained and will
    drag anywhere but won't insert into the clevis; least I can't get it to; gives a
    constraint error.

    ~Larry
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    *Rennick, Alan

    Re: Unconstrained part won't insert

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    12-01-2002 02:41 AM in reply to: *Caldwell, Larry
    Hi Larry,

        I think it's a geometry thing -
    the position of the clevis on the cylinder is too far retracted to allow the
    riser to insert to the Frame Tube AND to allow the roller to maintain tangency
    to the left(top?) tube.  If you suppress  the insert constraint
    between the clevis and the cylinder, then the constraint you are attempting
    works.  I can post in CF if my explanation is lacking :smileyhappy:

        I tried doing just a standard
    Mate on the centerline of the clevis thread hole and the cylinder rod, but that
    resulted in a constraint error as well, so my thought is that perhaps the
    cylinder centerline is just slightly off from the centerline of the riser/roller
    combination.  Hopefully this is enough to get you going.

     

    Cheers, Alan 


    style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

    First time I've seen this. In CF there's am
    assembly with two cylinders and two risers. One fits up nicely, the other is a
    different story. If anyone would like to give it a try, see if you
    can insert the Riser into the Clevis. The Riser is unconstrained and will
    drag anywhere but won't insert into the clevis; least I can't get it to; gives
    a constraint error.

    ~Larry
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    *Germer, Ole

    Re: Unconstrained part won't insert

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    12-01-2002 02:55 AM in reply to: *Caldwell, Larry
    Larry,

        The cylinder rod cannot be
    pulled out!!  The fixed length will not let the clevis meet the lug on the
    arm assy.  I fixed the arm to the lug on the arm to the tube. I tried to
    get the cyl. to meet the lug at the other end of the arm.  It fails. 
    The rod has to extract out of the cyl.  but it is fixed.

     


     

     

    style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

    First time I've seen this. In CF there's am
    assembly with two cylinders and two risers. One fits up nicely, the other is a
    different story. If anyone would like to give it a try, see if you
    can insert the Riser into the Clevis. The Riser is unconstrained and will
    drag anywhere but won't insert into the clevis; least I can't get it to; gives
    a constraint error.

    ~Larry
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    *Caldwell, Larry

    Re:

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    12-01-2002 04:21 AM in reply to: *Caldwell, Larry
    Oh ... I got it going okay, I just thought it was
    strange that a totally unconstrained part wouldn't take the first insert. Far as
    I know, there wasn't a tangent constraint on the roller. The roller was only
    constrained to the riser. I could drag the riser/roller in any direction as a
    confirmation that there were no constraints so why wouldn't it
    go? The clevis constraint shouldn't matter, I don't
    think, It was already in place. I agree it was likely a geometry
    thingy, the assembly is pretty messy but it's just a theory test for now. I
    usually use the sketches to build clean assemblies once the design is
    pretty-much settled. Thanks for taking a look.

    ~Larry


    style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

    Hi Larry,

        I think it's a geometry thing
    - the position of the clevis on the cylinder is too far retracted to allow the
    riser to insert to the Frame Tube AND to allow the roller to maintain tangency
    to the left(top?) tube.  If you suppress  the insert constraint
    between the clevis and the cylinder, then the constraint you are attempting
    works.  I can post in CF if my explanation is lacking :smileyhappy:

        I tried doing just a standard
    Mate on the centerline of the clevis thread hole and the cylinder rod, but
    that resulted in a constraint error as well, so my thought is that perhaps the
    cylinder centerline is just slightly off from the centerline of the
    riser/roller combination.  Hopefully this is enough to get you
    going.

     

    Cheers, Alan 


    style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

    First time I've seen this. In CF there's am
    assembly with two cylinders and two risers. One fits up nicely, the other is
    a different story. If anyone would like to give it a try, see if you
    can insert the Riser into the Clevis. The Riser is unconstrained and
    will drag anywhere but won't insert into the clevis; least I can't get it
    to; gives a constraint error.


    size=2>~Larry
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    *Caldwell, Larry

    Re:

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    12-01-2002 04:32 AM in reply to: *Caldwell, Larry
    Actually, Ole, on this particular iPart cylinder
    the rod can be extended in the iPart dialog using the key: Stroke Used. Like I
    said above, just thought it was a weird one and I had never seen that particular
    weirdness before. <G> Thanks Ole.

    ~Larry


    style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

    Larry,

        The cylinder rod cannot be
    pulled out!!  The fixed length will not let the clevis meet the lug on
    the arm assy.  I fixed the arm to the lug on the arm to the tube. I tried
    to get the cyl. to meet the lug at the other end of the arm.  It
    fails.  The rod has to extract out of the cyl.  but it is
    fixed.

     


     

     

    style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

    First time I've seen this. In CF there's am
    assembly with two cylinders and two risers. One fits up nicely, the other is
    a different story. If anyone would like to give it a try, see if you
    can insert the Riser into the Clevis. The Riser is unconstrained and
    will drag anywhere but won't insert into the clevis; least I can't get it
    to; gives a constraint error.


    size=2>~Larry
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    *Howard, Jeff

    Re: Unconstrained part won't insert

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    12-01-2002 07:16 AM in reply to: *Caldwell, Larry
    Hi, Larry.

    For future reference, it appears to be a bit of the strangeness that comes
    with tangent assy constraints. Either suppress the tan on the roller or place
    an angle constraint on the rod end clevis so it can't rotate on the shaft
    (confusing the tan?) and the insert can be applied and everything put together
    with the exception of the pin bore to frame.

    This is sort of contrary to what I've seen in the past where all other
    constraints had to be suppressed to get a tan to work. Different solver
    algorithms in 6 or just every set of conditions presents different problems?

    Have a good one,
    Jeff
    ====================

    "Larry Caldwell" wrote in message
    news:9BE97D017C8AAE8F75C564D9B5AE21AE@in.WebX.maYIadrTaRb...
    First time I've seen this. In CF there's am assembly with two cylinders and
    two risers. One fits up nicely, the other is a different story. If anyone
    would like to give it a try, see if you can insert the Riser into the Clevis.
    The Riser is unconstrained and will drag anywhere but won't insert into the
    clevis; least I can't get it to; gives a constraint error.
    ~Larry
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    *Caldwell, Larry

    Re:

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    12-01-2002 09:16 AM in reply to: *Caldwell, Larry
    Hey Jeff,
    I guess it could have something to do with the wily Tangent constraint
    phenomenon, but I still have all those constraints as they were. The way I
    fixed the one I have was to delete the cylinder/riser pad-eye
    extrusions/sketches and make new pad-eyes. Everything then constrained
    normally with tangent constraints and rotating clevis. Hard for me to
    discern a pattern from what I encountered to even be fairly sure of what was
    going on. I've kind of been leaning toward thinking that dirty files
    (meaning lots of changes, etc) lead to trouble similar to this example. When
    I do my clean files, I seldom have such problems. Have you seem similar
    results with your files? ... Oh ... Waite ... what am I saying ... you never
    make dirty files ... do you?
    ~Larry


    "Jeff Howard" wrote in message
    news:73DD1240B2ECAB2D7B6E63495CED9079@in.WebX.maYIadrTaRb...
    > Hi, Larry.
    >
    > For future reference, it appears to be a bit of the strangeness that comes
    > with tangent assy constraints. Either suppress the tan on the roller or
    place
    > an angle constraint on the rod end clevis so it can't rotate on the shaft
    > (confusing the tan?) and the insert can be applied and everything put
    together
    > with the exception of the pin bore to frame.
    >
    > This is sort of contrary to what I've seen in the past where all other
    > constraints had to be suppressed to get a tan to work. Different solver
    > algorithms in 6 or just every set of conditions presents different
    problems?
    >
    > Have a good one,
    > Jeff
    > ====================
    >
    > "Larry Caldwell" wrote in message
    > news:9BE97D017C8AAE8F75C564D9B5AE21AE@in.WebX.maYIadrTaRb...
    > First time I've seen this. In CF there's am assembly with two cylinders
    and
    > two risers. One fits up nicely, the other is a different story. If anyone
    > would like to give it a try, see if you can insert the Riser into the
    Clevis.
    > The Riser is unconstrained and will drag anywhere but won't insert into
    the
    > clevis; least I can't get it to; gives a constraint error.
    > ~Larry
    >
    >
    >
    >
    >
    >
    >
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