can't get my rail spline to attach to the 2 sketches.

can't get my rail spline to attach to the 2 sketches.

DonCMorrison
Enthusiast Enthusiast
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Message 1 of 9

can't get my rail spline to attach to the 2 sketches.

DonCMorrison
Enthusiast
Enthusiast

I have created the two sketches to loft between.  I then created a 3d spline between the center points of the two sketches.  I used a coincident constraint between the end points of the spline and the centers of the two sketches.  When I loft them I get a warning that the rail does not contact the sketches.  Do the center points not work?  The part is attached.

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Accepted solutions (2)
386 Views
8 Replies
Replies (8)
Message 2 of 9

jeff_strater
Community Manager
Community Manager
Accepted solution

There are two types of rail curves for Loft.  Centerline rails only require that the rail curve intersect the sketch plane.  However, if you are using "normal" rails, the rail curve must intersect the curves in the profile at some point, not just the sketch or the profile.  Your loft works with Centerline rail:


Jeff Strater
Engineering Director
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Message 3 of 9

g-andresen
Consultant
Consultant
Accepted solution

Hi,

This can be done with a single sweep

 

 

günther

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Message 4 of 9

evanp4509U4JZ
Collaborator
Collaborator

I'm always curious when I see this. Is there an advantage to one method over the other or a situation where one way is more appropriate than the other?

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Message 5 of 9

davebYYPCU
Consultant
Consultant

If you get the absolute same result, from multiple ways to get there, then

how much preparation is required for each method becomes the deciding factor at my place.

 

Loft is finicky, and has in built shrink wrap tendencies, 

My order of tool preference, is Pipe, Sweep, and Loft as last resort, for this example.

Pipe needs a centre line.

Sweep can accomodate offset paths, and some manipulation of the profile treatments.

Loft can accomodate different profiles

Each tool bringing in more complexity, requires a differing amount of preparation.

 

Might help….

Message 6 of 9

g-andresen
Consultant
Consultant

Hi,


@evanp4509U4JZ  schrieb:

I'm always curious when I see this. Is there an advantage to one method over the other or a situation where one way is more appropriate than the other?


In this case, the sweep tool is ideal due to its uniform profile.

In addition I recommend creating splines according to the principle of “less is more.”

This means that you should use as many control points as necessary, but as few as possible.

This way, you can achieve more harmonious curves by varying the lengths and slopes of the tangents handles.

 

günther

Message 7 of 9

laughingcreek
Mentor
Mentor

IF sweep achieves the desired geometry, it is better to use than a loft for a few reasons-

-(usually) easier to set up than a loft.

-less work for fusion computationally than a loft.

-better surface quality than a loft.

 

generally, you work thru the following possibilities, and the first method that achieves the desired geometry is the best one to use-

-extrude, revolve, planner patch.

-sweep

-loft

-surface patch

 

always exceptions of course.

 

 

Message 8 of 9

evanp4509U4JZ
Collaborator
Collaborator

Awesome info. Thank you all very much.

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Message 9 of 9

DonCMorrison
Enthusiast
Enthusiast

Thank you for the quick reply.   Sure answered my question.

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