Dragging the rails does not snap and attach to the points in the sketch

[hasaddl]

As shown in the video, based on the ellipses in the two sketches, when using the loft tool and dragging the anchor points at the ends of the rails, it fails to capture and attach to the points on the ellipses in the sketches, is this a bug? Or am I missing something? My operating system is macOS.

[etfrench]

Project/Intersect those points to the rail sketch.

[hasaddl]

I don't think that's the problem. These points are already present when the elliptical path is drawn in the draft, so there is no need to project the points to the rail sketch.

[etfrench]

Are the points in the rail sketch?  Did you try projecting the points?

[etfrench]

Can you attach your file to the thread?

[hasaddl]

OK, project file is attached
As shown in the screenshot, the point in the sketch (marked by the red circle) cannot be captured when moving the guideway

[etfrench]

It's pretty straight forward.  Use one sketch to determine the angle for a plane and the second sketch to connect the dots:

[hasaddl]

This method won't work unless I'm prepared to use sketch lines I've drawn myself to act as rails. But I don't want to use my own sketches as rails, I want to use the tangent direction rails generated by the Loft tool itself.

[g-andresen]

Hi,

if you work with surfaces instead of sketch profiles you can control the tangency.

günther

[davebYYPCU]

@etfrench @He is referring to mapping handles.

@hasaddl you can’t get Tangency control from sketch profiles, only body edges.

Might help...

[hasaddl]

Yes, I understand. You can check the attachment in the post above, I'm modeling a earphone and the loft operation is between solids. The problem I'm currently having on the Mac platform is that when Loft builds, dragging the position of the rails, it won't snap to the points on the sketch.

[hasaddl]

Can you make the start position of the loft rail perfectly coincide with the point marked by the red circle in the picture? I found it impossible to do so because there is no snap effect when the rail is dragged.

[TheCADWhisperer]

@hasaddl 

I would not mirror Splines.

I would fully define sketches (why is Sketch 3 not constrained to the Origin)?

I would not permit any unresolved issues highlighted in the Timeline. (Lofted Surface)

[TrippyLighting]

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@hasaddl wrote:

Can you make the start position of the loft rail perfectly coincide with the point marked by the red circle in the picture? I found it impossible to do so because there is no snap effect when the rail is dragged.

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You can. Whether that's a good technique can be discussed. It depends on the outcome of the loft. With tangent relationships for the rail splines and the loft this looks good:

[g-andresen]

Hi,

folow the screencast

Edit the offset of Body 5!

günther

günther

[etfrench]

Using sketches aligned to the points results in a fairly nice loft😁

[hasaddl]

This is the screen recording of my operation, you can see that the loft rail can't attach to the points on the sketch when dragging, roughly aligning by eye is not the way to model accurately in my opinion, I guess it might be a bug in the macOS version of Fusion360 that causes the rail to not attach to the points on the sketch.

[TrippyLighting]

In the video in my post I show the proper loft technique with blend curves as loft rails. That is much more reliable then hoping that those loft handles snap to anything.

[etfrench]

In order to use the points in a rail, you first have to project them to a sketch which is aligned to the two points.  This can be done by projecting those points to a sketch 90 degrees to those points, then drawing a line between the projected points.  This line is used to create a plane at angle. The two points need to be projected to a sketch on that plane.  You can now use a 2d spline to draw the rail between the two projected points.  Repeat for the other set of points.   The loft would be even smoother if you add rails at the other two quadrants using the same techniques.

@TrippyLighting's method of projecting using Include 3d Geometry  and the blended curve will give much finer surface

[hasaddl]

Thank you very much for the demonstration, I think this could be a good solution for placing the rails at the correct point.

But I'm still a little confused about the point attachment of the rails
The confusion comes mainly from this video:
At about 7:40 in this video, you can see that dragging the rail automatically snaps to the points on the curve in the draft.