finding reason for under defined

I am working in SW 06, in my sketch I have about 2/3 of my lines black
(defined). The other 1/3 are blue (underdefined). I cannot see where I
do not have a relation put in that it needs. Is there any tool that
will aide me in discovering where I need a relation to be put in to
fully define the sketch? I keep trying to add some dimensions, and am
getting over defined warnings.

 

The easiest tool is to grab a corner and pull to see what moves. If it does
move, then you can Undo to put it back and then you know what to define. If
it doesn't move, try another corner.

WT

 

To me, one of the best diagnostics available for determining what
constraints need to be added to your sketch is just to simply click
and drag on the various entities to see if any of them allow any
movement. Don't be shy about clicking and dragging on the sketch
entities--both the lines and the vertices. Once you've worked your
way around all the entities in the sketch, it should become obvious
what additional relationships are required. Sometimes, you may have a
situation where all the lines are black but the sketch shows as
underdefined--this can happen when there are vertices that are still
underdefined.
A very useful setting to help with this is under Tools, Options,
System Options, Sketch. Make sure that you enable the "Display Entity
Points in part/assembly sketches". This way, you'll see a dot at the
end points of every entity. If you adopt the habit of dragging on
your sketch entities, quickly, you'll get a more intuitive feel for
what constraints need to be added in order to fully define the sketch.

Something to look forward to in SW2007 is the SketchXpert command,
which provides some additional automation for fully defining a sketch.

If you're still having trouble with this particular sketch, I don't
mind taking a look at it for you--feel free to email me the part file
if you like.

 

What if you use the autodimension?

 

Good point. Autodimension will definitely work; however, it may not
give you a dimension scheme that's consistent with your design intent.

 

In addition, I wonder if there is a method to make it easier to find
the occassional darned little .001-.003" long bits that extend past an
intersection with no visibility when zoomed out of any color or
length?

I am sure that grabbing and dragging will work, but with 5-10 dozen
objects in the inevitable sketch which causes the problem, that is
still tough to find.

I have found one way with very complex sketches to be sure I don't get
an undefined object that is tough to find when I just know some
profile sketches are going to be a bitch.

In those cases, I dimension as I go along with each object or two or
three, even if I know I must change the dimensions and relations
later. This has advantages of letting me adjust the size of the
relative positions of entities in the sketch as I go along, if it
obviously requires a rethink or reposition of some element.

Bo

 

I want to thank all of you for the great suggestions! I also
discovered the diagnostic tools which I am also using.

 

Wayne, I agree with simple sketchs, as dragging 4-8 connections is
quick.

When dealing with the likes of an extrusion where there are a huge
number of entities, I find it particularly good to dimension as I go,
where at the WORST, I have the last item I just drew which might be
unconstrained on the non-connected end of an object.

The worst thing for me is sometimes getting rotated linear repeated
items to be fully defined. I generally get an idea of how they can be
not defined right, but it bothers me that a fully defined item after
mirroring becomes underdefined.

That is one of those niggling little things that bothers me. I have
just assumed it was endemic to the process and never thought of asking
if there is a way to avoid or fix the situation easily.

Bo