Selecting entities for dimensions

This is driving me nuts.....

I detail a lot of assemblies that are made from extruded aluminum frame
members (Bosch, 80/20, etc). When I use the Smart Dimension tool (or
ordinate, horizontal, vertical, etc), I have a very difficult time
picking the profile edges. SWX will select tangent edges of the corner
radii (tangent edges not displayed, select hidden edges unchecked)
instead of the profile edge of the member. To actually select the
correct edge for dimensioning, I need to zoom in closer to avoid the
tangent being highlighted. After that, I need to place the cursor on
exectly the correct position to get the edge to highlight. If I am off
by even a single pixel or two, the highlighting turns off! I then need
to zoom out and then back in again to select the opposite edge for
dimensioning, then back out again to place the dimension.

<flameproof suit>
In AutoCAD there is an option for the pick area size, and I seem to
remember UG and PRO-E having a similar feature. Is there somewhere I
can reduce the sensitivity of picking edges for dimensioning?
</flameproof suit>

Thanks!
Dave

SWX 2005 SP 3.0

 

This is the kind of thing a Spaceball will help cure.

The other thing is to use a different technique in modeling the 80/20
that would eliminate the minute detail added to the larger features and
place it in other sketches.

 

I have a similar problem. However, in my case I have square tubing with
sharp corners. What my computer selects is the inside corner. It is also
common for me to be unable to select an edge for the second item on a
dimension. I can select either edge, but only that one edge. I've also tried
selecting the endpoint instead, but again I can't select that second item
that the dimension needs.

I'm on 2005 sp 3.1

Joe Dunfee