create workplane

[wfrst2008]

Hi,
I attach a file here which containing an inplace Beam.
Can someone tell me how to attach a work plane to
any one of the 4 red faces ?

Thanks in advance for your help
WF

[Dimitri Harvalias]

It can't be done!
Your beam is a blended object and none of the highighted faces are a plane.
What is it you are trying to accomplish that requires the workplane?

[wfrst2008]

It's only a starting point for the object.
I need to add more on top of it which can only be done by
extrusion if I can make a workplane at the front face.
(you may refer to the attached image for detail)
Really can't do ?

[Dimitri Harvalias]

It can't be done in its present form. As I said, the beam is not a simple extruded box. It is created as a blended object and therefore none of the highlighted faces are actually flat, they are compound curves. A workplane needs to be defined as a flat, 2 dimensional plane.

Check out the modified file and notice the difference between the two blends.

[wfrst2008]

Thanks, Dimitri .

I get your point.
But as to my understanding, the purpose of using blend
instead of extrusion are :-
1. both ends are having different shapes ,
2. shapes at both ends are having a different orientations. (my case)

I have no option since the orientation is decided by the Engineer.

[Dimitri Harvalias]

Any chance you can use the end face of the beam as your workplane and then create another blend on top of the main beam?

[wfrst2008]

I just got a new idea.
I can use Vertex connect to break down the curved surface into
two warpped surfaces , then use one of them to do the trick.
Of course , it can just draw something very close to what I want
but surely it's not exactly .
and your suggestion worth a shot also. But the shape I want
will incl one solid plus one void, a bit time consuming.

best wishes
Fung