auto dimensioning

N/A

Hi,
I hope you can help me. I have only been using Solid Edge 2D for a short while but
I have a problem with my dimensioning not dynamically moving my objects.
For example, I have a connector I want to place 20 mm above the centre line of my
Printed Circuit Board. So I have created a centre line on my PCB. Now I create a
rectangle to represent the component I want to place and add a centre line to it.
I now expect that if I add a dimension between the PCB centre line and the component
centre line then the component will be moved to that position. There may be a clue
that all my other dimensions are in black but these centre line ones are in blue.
Another interesting thing is that if I change the dimension I have set between the
component centre line and the PCB centre line the dimension now has an underscore.
What does this mean?

your help will be appreciated as I'm banging my head against a wall now.
regards,
Richard
2 REPLIES

Re: auto dimensioning

N/A
The black dimensions are "driving" dimensions and the blue one is "driven".
The reason it is driven is because you are dimensioning to centerlines
created using the Centerline tool. Think of these centerlines as
annotations rather than actual geometry. You need to hang your dimension to
actual geometry that lies on the centerline of the PCB and to the center
point of your rectangal.
I've attached a simple pic to illustrate.
David

"Richard Petrie" wrote in message
news:45ddb4ea$1@bbsnotes.ugs.com...
>
> Hi,
> I hope you can help me. I have only been using Solid Edge 2D for a short
> while but
> I have a problem with my dimensioning not dynamically moving my objects.
>
> For example, I have a connector I want to place 20 mm above the centre
> line of my
> Printed Circuit Board. So I have created a centre line on my PCB. Now I
> create a
> rectangle to represent the component I want to place and add a centre line
> to it.
>
> I now expect that if I add a dimension between the PCB centre line and the
> component
> centre line then the component will be moved to that position. There may
> be a clue
> that all my other dimensions are in black but these centre line ones are
> in blue.
> Another interesting thing is that if I change the dimension I have set
> between the
> component centre line and the PCB centre line the dimension now has an
> underscore.
> What does this mean?
>
>
> your help will be appreciated as I'm banging my head against a wall now.
>
> regards,
> Richard



Re: auto dimensioning

N/A
Richard,
First I will explain the difference between the dimansions that you see that
are black and the ones that you see as blue. Dimensions may be driving
(changes to the dimension value changes the geometry). These are the black
dimensions. Dimensions may be driven (the dimension value is driven by
geometry and other dimensions. Geometry cannot be over constrained. You
cannot have two dimensions driving the same geometry.
Draw a horizontal line and place a dimension for the length of the line
above the line. Place another dimension for the length of the line below the
line. There is a single line with two dimensions. The black dimension placed
on the line will modify the line when changed. The green/blue dimension
placed on the line will not modify the line when changed. Two different
dimensions cannot drive the length of the line. This would be
overconstrained. The underline that is placed under the text of the
green/blue dimension when changed specifies that the dimension is not to
scale. This is standard notation.
Now for the centerlines. Centerlines are driven by the geometry they are
attached. Centerlines cannot be driving. Dimensions attached to the
centerlines cannot be driving dimensions. They will always be driven because
they are attached to the driven centerline. There are a couple of things you
can do. You can place dimensions to midpoints of geometry where the
centerline would be. You can also place lines with a centerline style and
constrain the lines to the geometry (midpoints). Then you can place the
dimensions to the lines and drive the location.
Regards,
Rick B.