Projected geometry

[Russ115]

I'm having a hard time using projected geometry on an adaptive sketch. For example, if I extrude a cube from a sketch in the XY plane and then I project a face from that cube to form another part, Inventor sometimes can't find the projection when you change the size of the original cube. I'm not talking about a complex assembly here, just one cube and one other part attached to the side of it and nothing more. It only seems to happen when you change the Y axis of the first sketch if it's in the XY plane but it will be some other axis if the original sketch (of the cube) is in some other plane. If you examine the sketch that's not adapting it's always just one side of the projected face that refuses to move, all other lines are OK. 

[JDMather]

I suspect there are far far better techniques to use.  Can you attach a typical assembly from your work?

[drguitarum2005]

I have the same issues. I often make sheet metal box assemblies and project the geometry from one part/flange to start the second one. When I change the size there is always a problem with itupdating correctly. I've had the best luck constraining the lines (horizontal/vertical contraints) to the projected geometry even after it is fully constrained.

An even better way in my opinion is to pick one part as your "base" part, put in all your geometry paramters as user parameters, then share them and link them to any additional parts. That way if I have to change the length of the whole box, for example, I change my "BoxLength" parameter in the base part and all other parts update too.

[Russ115]

I agree there are more reliable ways to attach parts than relying on dynamic projected geometry but the example I gave was just for illustration purposes, it's not something I'm trying to build. But it's still perplexing why it works on some faces of a perfectly symmetrical cube but not on others. While preparing an example to upload I discovered how to fix the problem which is to use the redefine function on the reference associated with the adaptive sketch. After doing that the projected part seems to adapt no problem at all to any further and continued re-dimensioning of the associated part. That seems to fix it but I don't know what causes it in the first place but I'll let you know if I figure it out.

[Russ115]

I agree with your second suggestion which is something I do all the time but with regard to your first suggestion how do you add more constraints after your lines are fully constrained?

[drguitarum2005]

For whatever reason, even though it says fully constrained, I can still use the vertical constraint tool (horizontal as well) to constrain the end point of a line to the endpoint of the projected line that I am matching. Doesn't make sense but it lets me.

[Russ115]

Interesting tip, I'll experiment with that and see what develops. If you read one of my comment above the Redefine function on the Reference seems to work quite well too.