Drive constraint within an assembly?

[abaird]

Probably a stupid question:

I have a cylinder assembly (downloaded from Parker), constrained to the stroke of the cylinder.  I can drive this constraint in the cylinder.iam file so that I can see the cylinder rod move up and down - all as expected.

Now this cylinder assembly is placed into a larger assembly and constrained - I can manually move the assembly, within the constraints of the cylinder.  Again, all as expected - no sick relationships or conflicts.  What I'd like to do is drive the cylinder stroke so I can see the whole assembly move as the cylinder is actuated - but now in the full assembly when I go to that relationship (under the "cylinder" component in the browser), "drive" is not an option.  Is this not possible, or am I just missing something?  Do I need to make a new constraint in the final assembly to make this work?

[JDMather]

Make sure your sub-assembly is set to Flexible (sounds like you have already done this - but you didn't mention it.

Then, yes create an appropriate assembly level constraint to drive the mechanism.

[abaird]

JD-  it's set as flexible, and that's what's allowing me to move it manually.  I was just really hoping I wasn't going to have to measure out some definition point at min and max strokes to add another constraint at the assembly level.  Seems like you should be able to do this (and I feel like I have at some point - I just can't remember how).

[JDMather]

You can set Position Representations for your min and max travel of your piston if all you want to do is display at these position reps.

[jpillitiere]

So I stumbled upon a quick and dirty way to drive your subassembly constraints in a larger assembly, in real time.  First, make sure your driven assembly and the larger assembly are in the same instance of inventor.  In other words, make sure the two assemblies are just separate tabs in the same inventor window.  Then go into the assembly with the driven constraints, right click on the desired driven constraint and click "drive".  After the window pops up with the drive controls, click back to the tab with the larger assembly.  The drive control window should still be visible.  From there, set your controls how you'd like and click play.  You can then watch the driven assembly move in real time in the larger assembly.  Just know that if you start to change anything in the larger assembly or click to make something active in larger assembly, the control window will disappear, and the driven assembly will revert back to it's original position.  If this happens just go back to the driven assembly tab and open the drive control window, then go back to the larger assembly.  Hope this helps!

[johnsonshiue]

Hi! I think I know what you are after. It is indeed not yet doable. It is because the solve happens in the subassembly context, which is not in the top-level assembly context. If you want to drive the constraint, the constraint has to be within the edit context.

This is an interesting idea. Please feel free to add it to Ideas forum.

Many thanks!