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*Caldwell, Larry
Message 1 of 7 (56 Views)

Unconstrained part won't insert

56 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
*Rennick, Alan
Message 2 of 7 (56 Views)

Re: Unconstrained part won't insert

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
*Germer, Ole
Message 3 of 7 (56 Views)

Re: Unconstrained part won't insert

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
*Caldwell, Larry
Message 4 of 7 (56 Views)

Re:

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
*Caldwell, Larry
Message 5 of 7 (56 Views)

Re:

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
*Howard, Jeff
Message 6 of 7 (56 Views)

Re: Unconstrained part won't insert

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
*Caldwell, Larry
Message 7 of 7 (56 Views)

Re:

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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