Difference between chain face and extend face in extrusion

[Anonymous]

Hi all,

I have a subassembly that is to be placed within a container box (separate component). I've placed the sketch at the origin. When I start to extrude the sketch that represents the box I need to extrude two sides. If I select extent as "Distance" and click the face within the subassembly, the extrusion happens but won't be dynamic - if the subassembly changes, the extrusion will not. If I select "To Object", and select the face, I get a tool body error. Only at this point can I change from "Chain faces" to "Extend faces", which seems to do the job.

I was about to attach pictures but this screencast shows this happening in the exact same way. I guess this means that this is ok, it's official behaviour.

My main question is - what is the difference between "Chain faces" and "Extend faces". It isn't in the documentation that I can see. I guess "extend" means, well, extend the face but I'm unclear about the meaning of "chain".

Thanks.

[Phil.E · Accepted solution]

Chaining always refers to tangent connections.

Chaining edges is an option for some commands, where you might want to pick all the connected tangent edges by picking just one edge.

Chaining faces for extrude is for when your extrude profile needs to run over onto an adjacent tangent face.

If you still have questions let us know.

Thanks,

[Anonymous]

Thanks, I believe I see the difference - looking through my other designs I can see the difference in the extrude (see picture - ringed area was extruded in the direction of the arrow, left is extend and right is chain). Chain seems a little bizarre sometimes because you might not spot all the faces in the extrude path that get involved.

Thank goodness for section analysis!

[Anonymous]

Thanks, I believe I see the difference - looking through my other designs I can see the difference in the extrude (see picture - ringed area was extruded in the direction of the arrow, left is extend and right is chain). Chain seems a little bizarre sometimes because you might not spot all the faces in the extrude path that get involved.

 Thank goodness for section analysis!

[Anonymous]

Thanks, I believe I see the difference - looking through my other designs I can see the difference in the extrude (see picture - ringed area was extruded in the direction of the arrow, left is extend and right is chain). Chain seems a little bizarre sometimes because you might not spot all the faces in the extrude path that get involved.

 Thank goodness for section analysis!

[Anonymous]

I only replied once by the way! The forum system replicated the post for each picture edit! I can't delete the extraneous posts 😞

[Phil.E]

No problem, I've reported it to the person who can remove the double post.

[kb9ydn]

I'm still not getting the difference between chain faces and extend faces.  What faces is this referring to?  Also this still needs to be added to the help docs.

C|

[kb9ydn]

I found a better explanation in another thread:

http://forums.autodesk.com/t5/design-validate-document/distance-to-not-working/td-p/6731902

So I (think I) see the difference now.  The terminology of "chain faces" and "extend faces" still seems odd though and not very obvious.  I feel like it would be better to get rid of the "chain faces" and "extend faces" setting completely and instead add another Extent selection called "up to next".  "Up to next" would act like the "To Object" Extent with the "chain faces" option.  The "To Object" Extent would act like it does now with the "extend faces" option.

To reduce confusion, if there is no end condition for any part of the extrusion, the option for "Up to Next" should not be available as it would fail.

C|

[Phil.E]

@kb9ydn

Thanks for posting the link to the other thread. The Help for Extrude needs to be updated, we are aware.

While I don't think we are going to change the names or labels any time soon, you should feel free to post your idea for relabeling the extrude command options in the Idea Station. Who knows, maybe a bunch of people agree with you and we need to take notice! 

For now, since there isn't a good help page, here is a graphical explanation of the extrude options.

Please let us know if you have any more questions.

Regards,

[kb9ydn]

@Phil.E  That's a much clearer explanation; big thanks for that!

I don't know if the labeling change is a big enough deal to put in the ideastation, so maybe I'll wait and see if anyone responds here first.  

C|

[Victoria.Studley]

Hi @kb9ydn,

I'm following up to let you know that we've revised the terminology for the Extend options in the Extrude dialog.

Specifically, we:

• Clarified the setting labels
• Added tooltips to the dialog with descriptions of each setting
• Updated cursor prompts to provide better guidance in the canvas
• Updated the documentation to reflect the changes

Here's an animation that illustrates the changes:

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