Constrain lines in 2 different stetches

[SGoldthwaite]

Is it possible to use the constraints tools to form a relationship with lines in two different sketches?  I have one sketch with a square and another with a line perpendicular to the plane of the square sketch.  If I move the square, i'd like the perpendicular line to move also.

[Phil.E]

Yes! This is really easy and part of the core parametric functions of Fusion.

What you want is accomplished by projecting geometry from one sketch into the next.

In the case below, you can see I made the rectangle in Sketch 1.

1. Sketch 2 is on the same plane (it doesn't have to be)
2. The edge from Sketch 1 is projected into Sketch 2.
3. While drawing Sketch 2, use Project Geometry and select the edge in Sketch 1.
4. The Sketch 2 objects are constrained/dimensioned to this projected edge.
5. Edit Sketch 1 and Sketch 2 will update.

This is really the same exact workflow as used for solid bodies and sketches. If you project edges from a solid body into a sketch, then go back and edit the solid body, the downstream sketch will update accordingly.

[SGoldthwaite]

I can't figure this out for my model: http://a360.co/1BRqyTv

I have one sketch called A-frame.  Protruding from it are 4 lines. The top 2 lines are in a separate sketch called Top Bars.  The lower pair of lines are in a sketch called Bottom Bars.  I want to change the height of the A-Frame sketch, and when I do I want the 4 bars to change height as well.  I tried projecting the bar, but it projected a line down to the floor.  I want it to project on to the A-Frame sketch as a point.

[jeff_strater · Accepted solution]

Sorry to jump in here, Phil, but I'm sitting around waiting for Fusion to build, so I have some time to look at this.  Your case is slightly different.  In this case, what you really want is the sketch plane for Bottom Bars and Top Bars to be dependent on the A-Frame sketch.  I see, though, that Top Bars and Bottom Bars sketches contain 3D geometry (the sketch planes are on the global XY plane):

so, the approach is a bit different.  Instead of Project, you need to use Include 3D Geometry in your sketch, because they contain 3D geometry.  The basic idea is that we can include geometry from the A-Frame sketch into the Top Bars and Bottom Bars sketches, then make the lines in those sketches coincident with that included 3D geometry.

Here is a screencast of how I did this for Top Bars:  http://autode.sk/1I0IWhO

I did the same for Bottom Bars as well.  I've attached the model after these changes, just FYI

Please reply if you have further questions.

Jeff Strater (Fusion development)

[SGoldthwaite]

Thanks!!!  That worked.  What are you doing in the screencast at 28 seconds?

[SGoldthwaite]

I just posted a follow-up question here: http://forums.autodesk.com/t5/general-fusion-360-questions/bd-p/124

I'm now trying to add a dimension to the lines in Top Bars sketch, but can't.  I started a new thread because it seems to be a different issue.

[jeff_strater]

Hi Scott,

Yes, as indicated in that other post - dimensions only apply to 2D geometry (so far...).  The recommendation of using a 2D sketch for this is probably the easiest for this particular design.

Oh, and at 0:28 in that screencast, I'm just trying to get out of the coincident command .  I was fumbling around with the marking menu just trying to get to OK.  Hitting the ESC key would have been easier...

Good luck with this design!

Jeff