How to use edges as loft rails?

[Anonymous]

I have two profiles that touch at the ends of two edges, as seen in the attached image. I'd like to create a loft between them that follows the edges as guide rails, but while in the loft menu the edges are unselectable as guides. I've tried projecting/including these edges in a sketch as well - they aren't selectable there either. How do I either turn the edges into a 3D sketch, or use them as loft rails?

Thanks!

[HughesTooling]

Did you click the arrow next to the Rails option to enable rail selection?.

Mark

[Anonymous]

Yes. I could select other lines to use as rails, but not the edges. 

[HughesTooling]

It looks like you could export that component on it's own and upload. Just right click the component in the browser and select Export, pick f3d as the file type and attach to this thread.

Thanks Mark.

[Anonymous]

File attached.

As I mentioned, I can select sketch lines to use for rails, even ones that don't attach to the profiles (which produces an error) but can't select the edges at all. 

[gautham_kattethota]

Hi,

Thanks for attaching the file.  Yes, I see the edges are unselectable for use as Rails.   

I could project the edges into a sketch using the "Include 3D Geometry" command.  To use this, invoke the sketch command and select some plane, doesnt matter which one.  You then use the "Project/Include > Include 3D Geometry" command under the Sketch dropdown and select the desired edge.  Using this I created two sketch curves running along the two edges.  I can use one of them as a Rail for the loft.  But using the other one is throwing an error.  

We will check these issues and get back to you.  

Regards,

Gautham

[gautham_kattethota · Accepted solution]

Hi,

You cannot pick the edges as rails for Loft because we allow edges from surface bodies only to be selected as rails, i.e., an edge with only one face connected to it.  The body in your case is a solid body, so each of those edges you are trying to pick has two adjacent faces.  

So the alternative is to project the two edges into a sketch and use the resultant sketch curvees as a rails, using the "Include 3D Geometry" command that I mentioned in my previous post.  For this case, it looks like loft succeeds when only one of those sketch curves is picked as a rail.  Selecting the second rail results in an error.

I have reported this to the relevant team.  We will check if the issue can be fixed, soon.

As a workaround, if you dont mind creating this loft as an independant body, i.e., not Joined/Combined with the existing body "Body2", you can follow these steps:

1. Create sketch curves for the two edges using the Include 3D Geometry command.

2. In Loft, select the two profiles and the two sketch curves as rails.  Note that the order of selecting the rails is important.  In the attached image i have marked the two rails as Rail1 and Rail2.  Select Rail2 first followed by Rail1.

3. YOu will see an error about problems with combining geometries.  In the loft dialog, under the Operation dropdown, select "New Body" option.  This will prevent the error.

4. Loft should now succeed.  

Only thing is you will have a separate body created by this loft.  If that is acceptable for you, you could try this workaround.

If you want any further details or clarifications, you can send me an email: KATTETG@autodesk.com

Regards,

Gautham

[gautham_kattethota · Accepted solution]

Ok, I found a simpler alternative.  You could use the loft command to do the entire shape for Body2 in one shot - instead of using a combination of Extrude, Sweep and finally Loft (that fails).  

Please Look at the attached file and see if this meets your needs.

Gautham

[Anonymous]

Thank you for taking the time to look into this. Actually this all came about because I couldn't find a variable fillet option - does such an option exist, and if so, how might I create one? I couldn't find a way to do it in the current fillet options. 

[gautham_kattethota · Accepted solution]

Yes, variable Radius fillet is available in the FIllet command.  You have to change the Type dropdown to "Variable Radius" as shown in the pic below.  Note that the TYPE dropdown only appears after you select an Edge for fillet.