I've not tried this on an ordinate dimension, but it works on a linear dimension: make a circle ID symbol with no text and associate the origin to your dimension. You will have to play with the size and origin offsets to get what you want, but when/if you move the dimension, the balloon will follow.
When you try to select the balloon, hold the left mouse button down and you should get the pick list to pop up after a short delay. Choose the ID symbol from the list and edit as necessary.
John,
I'm not sure if this is included in any general international standard, but is very common in aerospace to define buttline, waterline and fuselage station locations.
I've always had to fudge it, using dimensions with lines turned off (or, gasp, dumb text) and split balloon symbols.
"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]
ewh is right, but for aerospace they will often define the two planes normal to the face of the drawing in the one circled annotation. Some automotive suppliers still do likewise as well.
So in order to achieve it associatively one has to perform a great deal of gymnastics. In the past I have seen some people create dimensions with no arrows or leaders and position them within the bubble of an ID symbol.
A better way may be to take measurements from a datum system and plug them into expression strings, as per the attached example.
In the example unsuppress the offset to see what happens.
It works but nobody I know bothers to do things like this because it is probably too manual for day to day use. A lot of people do however have grip programs and the like to achieve similar results and that would be my suggestion in this case as well.
Thanks to all for your help. It looks like there's no easy way to accomplish this task. I need a true dimension so I will have to use a blank ID symbol.
