Using Expression to Control Line Length

[CPaul]

Hi guys,
I'm playing around with our template right now and want to use an expression to control the length of a line. I can't get the line's length to update when I update the expression and was wondering if it isn't possbile to do.
When sketching on the sheet, I can get a line to update the way I want it to, but not with a line not within a sketch.

I attached an example. Thanks in advance,
Chris

 

[JohnRBaker]

There is no support for parametric (expression-driven) curves when working in a Drawing. You have to model those curves in Modeling and then create a Drawing of the model.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.

 

[rg006]

The easiest, and best, way to do this is in a sketch. If you draw a line in a sketch and use the expression to control the length that should work. Also, keep in mind that when it comes to positioning the sketch you have three options. The quickest is to use a constraint and "fix" the end point. The Second way is to use a horizontal and vertical dimension to fix the line by referencing a datum. The third way, and most useful, is to close the sketch without it being fully constrained. Then right click the sketch and use the "Edit Position" methode to position the sketch. This keeps the sketch together as if it were a block in autocad (if you have used that before). You can use expressions to controll everything I have talked about except the "fixed" constraint. Keep in mind that if you want your drawings to update correctly, then using the "edit position" option becomes very helpful. You can constrain a sketch to dumb geometry, and then use "edit position" to move it into the correct placement.
Hope this helps.

UG NX3/NX4/NX6
Vericut 5/6/7
AutoCAD LT

 

[JohnRBaker]

But the OP already said that he did NOT want to use a Sketch. Without using a Sketch, there is no way to do this in Drafting.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

UG/NX Museum:

http://www.plmworld.org/p/cm/ld/fid=209

To an Engineer, the glass is twice as big as it needs to be.