LOft : is a rail can be in many pieces (connected, of course)

[cali.season26]

Hi,

I have a problem with creating a loft (the post https://forums.autodesk.com/t5/design-validate-document/loft-problem-with-rails-surely-already-asked...)

But I have a more general question :

can a rail be made of

 - a line for the the 3 first profiles

 - a spline for the 4th p

 - another spline for the profiles 5 to 8,

 - another spline for profiles 9 to 10 ....

and so on. This rail is of course continuous, and even differentiable (all lines are tangent to the next curve).

Because, despite that I accuretaly constructed the intersection with rail1 and2 with every profile, my loft stops at the 4th profile (the transition between the line and the spline).

To be very precise, the rail 2 is a projection on a surface of a plane sketch, gathering a line, a spline, a line, an arc of circle, a line and a spline.

The surface is ruled (an extrude), done with a single spline.

Tx for your infos.

[Beyondforce]

Hi @cali.season26,

Will you please use the Screencast to show your problem. It will be much easier for everyone to understand your question and possibly give you a better solution.

Cheers / Ben
---------------------------------------------------------------------------------------------------------------------------
Did you find this reply helpful ? If so please use the Accept as Solution or Kudos button below.

Check out my YouTube channel: Fusion 360: Newbies+

[cali.season26]

Here is screen view of the problem :

At first, I can create Loft P1P2 with profiles 1 and 2, rails 1 and 2

The same with a LoftP3P4 with profiles 3 and 4, rails 1 and 2

But I can't build a loft, gathering the profiles 1 to 4, and rails 1 and 2, since the rail 2 has 2 pieces.

Solidworks permits to create a curve, dubbed also a spline in SW, to agregate 2 curves (even if they aren't tangential, if I am right), I didn't find the equivalent feature in Fusion.

So, how can I get such rail 2 for my Loft P1P4 ?

The file of this problem is attached in the post.

The rail 2 is get after a projection of the plane sketch pattern_rail2 onto the surface body_1.

 Tx for your help.

[Beyondforce]

Well, there seems to be a disconnection in the rail line. I have tried to connect it, but with no success. Maybe @jeff_strater knows why they don't want to connect!

[cali.season26]

The spline living into the plane pattern is tangent to the line, and the surface body_1 is a manifold too, so the projected curve should be a manifold ...

[davebYYPCU · Accepted solution]

For connected rails, there is a trick, 

Uncheck "Chain Select" (makes total sense to others)

select rail part 1, hold (Cntrl / Cmmd) key

select more rail parts.

Make sure Loft - is adding your rails in the window, but Not adding Rails in the dialogue box.

Have not downloaded file yet, not at Fusion for a while today.

Edit:  Forgot to tell you, the error "Not touching all profiles," will go away after all rail sections are selected.

[cali.season26]

Tx a lot.

Your tip works on this file.

[davebYYPCU]

Ok, great.

[jeff_strater]

Thanks @davebYYPCU.  I did not know that works.  Glad you shared that.

However, this still seems like a bug to me, that you have to turn off chaining in order to chain rail curves.  I'm going to investigate this.

Jeff

[davebYYPCU]

Happy to help out, 

Somewhere in the back of the head - I think I have to do that with sweeps as well, but don't quote me on that one.

"Chain select" works as expected for profiles, by that I mean click a curve and it will select the closed profile where that curve is a participant.

[cali.season26]

Hi,

The problem isn't totally ended for me :

a multi-pieces rail can be done with a projected curve on a surface.

The rail 2 is declared as one rail in the rail box of the loft, but not the rail 1, which is contained in a plane sketch.

Then, one piece of the sketch = one rail, even with the option "Chain Select" unchecked

Here is the file of the problem, with profiles 1 and 2.