Loft smoothed in two dimensions to rotated target?

[d.roettsches]

Hi at the Fusion 360 forums,

in this bike phone holder design I would like to create a smooth loft guided by splines in the plane that connects the two parts, as well as in the lengthwise cross-sectional plane (screenshots below). I indicated how I'd like the shape to look from the side and from the top.

I've tried using the loft with a guide rail, but that produces the desired outer contour only on the right side, while it creates an undesirable contour on the opposite side. Also, the loft is then not correctly smooth with the top and bottom surfaces.

Perhaps a loft is not the right tool? 

So I have mainly two questions:

1. How can I create a smooth, organic looking curved body between the two parts where the curvature is smooth with the top surfaces as well as the outer sides?
2. Can the curvature smoothness constraint be used in multiple dimensions? I was unable to move the spline control points vertically away from their sketch plane.

Thanks everyone for tips and suggestions.

Edit: Attachment added.

[jeff_strater]

it would be best to share your design here for better/more help.

But, yes, loft is the tool you want here.

A couple of comments:

• "I've tried using the loft with a guide rail, but that produces the desired outer contour only on the right side, while it creates an undesirable contour on the opposite side." - need to see the model and/or screen shots, but in general, you should be able to get good control using loft with rails if you have it set up well.
• "How can I create a smooth, organic looking curved body between the two parts where the curvature is smooth with the top surfaces as well as the outer sides?"  By "outer sides", I assume that you mean the vertical faces?  The answer here is "yes", that is what the Tangent or Curvature condition will do for you.
• "Can the curvature smoothness constraint be used in multiple dimensions? I was unable to move the spline control points vertically away from their sketch plane."  Can you clarify what you mean by "multiple dimensions"?   For 3D splines, you have to use Move to move the control points/tangent handles, etc.

[g-andresen · Accepted solution]

Hi,

try this symmetric extrude and split body with the existing profiles.

günther

[d.roettsches]

Beautiful, great idea, thank you so much, Günther! (Do you accept donations?)

[d.roettsches]

Hi Jeff,

thanks for replying and trying to help.

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@jeff_strater wrote:

it would be best to share your design here for better/more help.

But, yes, loft is the tool you want here.

A couple of comments:

• "I've tried using the loft with a guide rail, but that produces the desired outer contour only on the right side, while it creates an undesirable contour on the opposite side." - need to see the model and/or screen shots, but in general, you should be able to get good control using loft with rails if you have it set up well.

The model is attached, linked from the gallery available for download, and attached as file. I am curious how I would use the loft tool for this purpose, I was not able to constrain the loft on both sides (left and right looked from the top), and in the vertical dimension (up, down, looked at it from the side).

• "How can I create a smooth, organic looking curved body between the two parts where the curvature is smooth with the top surfaces as well as the outer sides?"  By "outer sides", I assume that you mean the vertical faces?  The answer here is "yes", that is what the Tangent or Curvature condition will do for you.

Could you explain in more detail how to add a curvature constraint in a dimension that is not "flat" with the sketch plane? For the outer lining curve, I have the curvature constrained so that it's smooth length-wise with the frame of the upper phone holder bracket as well as with the mounting strip at the bottom. But I would like to make it smooth with the vertical faces on the side at the same time, is that possible?

• "Can the curvature smoothness constraint be used in multiple dimensions? I was unable to move the spline control points vertically away from their sketch plane."  Can you clarify what you mean by "multiple dimensions"?   For 3D splines, you have to use Move to move the control points/tangent handles, etc.

Tried to explain that above. I was only able to apply curvature constraints within the sketch plane dimensions, not vertically away / down through the sketch plane.

Appreciate any tips you may have.

[jeff_strater]

sorry, I missed the attached file - thanks for sharing that.

As far as creating tangent relationships to model geometry in splines, the key things, I think, are the Include 3D Geometry command, and making sure that 3D sketch is enabled.  In the screencast, I show the basic idea, though I am not 100% sure that this is exactly what you want, it might help suggest some things to look into..

I would definitely heed @guenther.andresen 's advice - if a design is inherently symmetric, use that, and only model 1/2 of it, and use Mirror to get the other half.  But, you can do this all at once, it requires adding rails to both sides.

[g-andresen]

Hi,

Glad to hear you like the solution.

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@d.roettsches wrote:

(Do you accept donations?)

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No, because for me the forum is a place to get help and support working with Fusion without have to pay or getting paid for it.

günther

[d.roettsches]

Hi Jeff, 

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As far as creating tangent relationships to model geometry in splines, the key things, I think, are the Include 3D Geometry command, and making sure that 3D sketch is enabled.  In the screencast, I show the basic idea, though I am not 100% sure that this is exactly what you want, it might help suggest some things to look into..

So cool, that's a very elegant solution, too. Modeling the tangent / curvature relationship in 3D space was exactly what I was looking for. The "Include 3D geometry", I'll experiment with that. Exciting to see, that a very similar solution is possible with the Loft tool was well. 

Thanks a lot for your help!

[chrisplyler · Accepted solution]

An easy option:

https://knowledge.autodesk.com/community/screencast/4a10d598-860f-4de2-b3b0-f8fbd2a55702

[d.roettsches]

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@chrisplyler wrote:

An easy option:

https://knowledge.autodesk.com/community/screencast/4a10d598-860f-4de2-b3b0-f8fbd2a55702

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🤩Wow! 🙂 I had no idea this option existed, bu this is indeed by far the simplest approach in this case, when no additional control over the curvature is needed. Thank you, very helpful!

[chrisplyler]

Glad to help when I can.

It is advisable to have a look around all the option settings available when you activate a tool, and even experiment with them, such that you start to learn what is possible.

Good luck!