Why Can't I Dimension This Edge To Another [Projected] Edge?

[glencandle]

I have a design that I want to be dynamic from start to finish, where changing the length of one edge at the beginning will dynamically resize everything through to the end.  

Seems pretty basic, as far as procedural design goes.  But for some reason when I get two layers deep into my projected edges, Fusion no longer wants to be dynamic.

I've attached an example project to illustrate what I mean.  I want the sketch on the left to be sized according to the one on the right.  That sketch is also dynamic to another sketch.  It seems that going another layer deep (i.e. projecting an edge that is also sized off another projection) is not allowed.

Is there a way around this limitation?

[jhackney1972]

You are getting into problems because your dimensions you are trying to reference are "Driven" dimensions or reference dimensions.  In the video I explain two ways to get around this problem, the latter is probably more preferable if I am guessing your workflow correctly.

[jeff_strater]

Thanks, @jhackney1972 for looking into this and providing another way to do it.  However, I think that @glencandle 's question is valid - this should work.  You can definitely refer to a driven dimension in the same sketch.  And, this works in simple cases.  There is something going wrong here that I will send to the team to investigate.

[edit] I created bug FUS-142240 for this issue

[glencandle]

Hi John, thank you for taking the time to outline both of the methods in your video.  Unfortunately neither method will work for me for the following reasons:

METHOD 1: Using an Equal Constraint

REASON: I actually want to make the Dimensioned edge a fraction of the edge in question (i.e. d56 * .2)

METHOD 2: Breaking the Projection link

REASON: I need to keep everything dynamic

I've actually found a workaround that is very strange, but seems to work for now.  Rather than Project the edges, and then using a Constrained Dimension on that edge as a reference (which as we know does not work), I can instead Project the points, then draw a line between the Projected points, then created a Constrained Dimension of that line to drive the Dimension of the line I want to be a fraction smaller, dynamically.

That really was a confusion description I know, but I'm doing my best over here.  Again, thanks for taking the time 😉

[glencandle]

Thanks John, I appreciate that, and hopefully it will be fixed.  I've actually encountered this issue more than a few times in the last couple of years but I always just found a workaround and didn't take the time to raise the concern until now.

On that note, I did find a workaround this time as well:

It seems I can project the points in the sketch and then draw a line between them, to achieve the same dynamic functionality as if I projected the original line itself.

[deepika_gohrani]

Hi @glencandle, I checked the file, seems there is some issue with dimension d27, looks broken/corrupt, if you delete and re create it, it will work properly. Also if we open this project and compute all once , then too dimension is corrected and referring to that driven dimension will work. Please try any of the workaround and let me know if you need more support with that.

Deepika Gohrani
Autodesk.