Error: The rails do not intersect all profiles

[Anonymous]

I am new to the whole 3D CAD community. 

I am trying to create a shoe last in Fusion 360.  Currently I am trying to model the back/heel part using Loft and Rails.  The profiles select but when adding the rails the error message displays "2 Error(s): The rails do not intersect all profiles"

I watched various screencasts in this forum on loft and rails, tried to apply that to what I am doing but with no success.  I used the 'Intersect' command to intersect the two profiles to the three splines I am using as rails .  (Each spline point snapped to the purple dots on the top and bottom profile)

Are you able to see something that I might be doing wrong in the attached screencast?

Is there something about the bottom profile shape that is unable to use the rails?

[masa.minohara]

Hi @Anonymous,

Welcome to Fusion community and thank you for posting! Honestly I am not sure why the issue is occurring without looking at the file but could you try the Loft command in the Patch workspace and then the Stitch command to create a solid body? If this doesn't work, would you be able to share a public link to the design with me?

[Anonymous]

I am having a similar problem and I think I have found the cause. When a spline is intersected with a sketch and you then zoom in maximum to the intersection point you will see that the intersection point and the spline do not coincide. Hence the error message. Could this to be a bug?? With an arc intersection there is no problem.

[jeff_strater]

yes, @Anonymous, if you find that using Project Intersect with a spline curve and another sketch does not generate an accurate point, that would definitely be a bug.  If you can share your design, we'd be happy to take a look at it.

Jeff

[Anonymous]

Hi Jeff,

Thank you for the prompt response. There is no actual design as such to share, but if you sketch any single spline and intersect it with a second sketch at say right angles to the spline sketch, then when you zoom in to the maximum you will see that the intersection point and the spline apparently do not coincide. However, I cannot replicate the error in any simple lofting example - everything lofts just fine. My bug seems non-existent. I will revisit my somewhat complicated design to see if I can spot my error. If I may, I will report back later.

Regards

John

[Anonymous]

Hi,

I have been playing around with a few things. Try un-checking the Chain Selection before selecting the loft rail.

[Anonymous]

Was this ever resolved? I'm continually running into this problem whenever trying to loft profiles that involved intersected splines. It's a huge headache and time waste trying to create simple lofts.

[Anonymous]

Hello,

I'm facing the same problem. And I have no clue what I'm doing wrong.

I watched numerous videos on loft function, but whatever I'm doing, I get errors, but no correct loft.

I'm trying to design the half hull of my boat following this video : 

https://www.youtube.com/watch?v=ixGnJjNPj18&t=521s

My model's public url : 

http://a360.co/2tfGPWj

If someone could help by telling what I've been missing That would be very nice 🙂

Thanks,

Alain

[Anonymous]

@jeff_strater Your lessons on lofting and projecting points got me through this problem this week. I don't have a ling handy for these people however. It can be maddening to see a point that looks like it is coincident but when you zoom in it is a few thousandths off. It was only bu deleting the offending line and redrawing it That I was able to find them all.

[cekuhnen]

@Anonymous @Anonymous

This is a pretty old and known bug in the sketch engine among others.

The engine has some problematic areas that make certain modeling tools fail but to my understanding AD

is focusing the sketch engine bugs that are in the system since 1 to 2 years.

So this should soon work.

[SaeedHamza]

Hi,

Could you please attach the file so that we can check it

Regards

Saeed

[Anonymous]

I found Jeff's Screencasts,the helped me a lot.

https://forums.autodesk.com/t5/fusion-360-design-validate/lofting-and-projection-include/m-p/7223042...

[Anonymous]

Thanks everyone for your help.

I finally manage to have a loft that is close enough to what I wanted without using rails : http://a360.co/2tfGPWj

But I learned a lot doing so.

Thanks again. 🙂

[cekuhnen]

@Anonymous

That's awesome! What did you change? Did you stay away from using using curves created via projection or intersect?

I find when those tools are not used the sketch engine is a lot more predictable as those tools still have some unresolved issues.

[Anonymous]

In fact I'm not sure I understood the heart of my problems with rails not intersecting all profiles 🙂

I tried to model my hull following this video and at some time the video shows that you have to create a loft between the transom (?) and the middle line. Then using horizontal lines as rails.  

https://youtu.be/ixGnJjNPj18?t=1269

This is where I failed whatever I tried.

So I took another way, I created a sketch for each vertical plane then created a loft between all of these surfaces (the blue one in the attached screen capture).

This way I didn't need to use rails. It's not exactly what my hull looks like (there are some slight differences), but it's close enough for what I want to do.

I put on google photos the related pictures for this project and I'm planning to do a video at some point : https://goo.gl/photos/EdTkiePYdZ8Ncke99

[bradanlane]

I am getting the "rails do not intersect all profiles" error.

In my project I need to create two lofts.

In each case the loft is between the faces of two extruded bodies.

In each case I need to create four splines to use as rails and control the loft. Each spline generally controls one side of the loft (top, bottom, left, and right).

One loft is working fine.

One loft fails with the error. If I add one spline at a time, I can verify that one spline os "OK" and the other three all cause the error. I have deleted and recreated the offending splines several times and they always cause the error when I attempt to use them as rails.

I will attempt to create a simple example project but I am hoping there is a way to debug one of the offending splines so I know what I am doing wrong (and whie one spline worked and three do not).

[davebYYPCU]

How are you connecting the end point of the spline to the face of the body.

Only Project > Intersect points into your spline sketch works.

[bradanlane]

My splines have only two points. I use the control handles to form the necessary curves.

I start each spline zoomed in on one face and move the mouse until it snaps to the edge of the face. If I need to have the spline start at a midpoint, I move the mouse as needed until the midpoint constraint appears. I click the mouse and then move to the other face and repeat the process.

One the spline "line" is created, I edit the handles on each point to form the desired curve.

(I hope this is somewhat clear. I realize a screencast or file would be more helpful.)

[Anonymous]

Lofting has been very frustrating for me. It is easy to not get a good rail. I should say that I am pretty new to Fusion and am working on drawings that are beyond my abilities. I have been lofting complex transitions between curves in guitar shapes for about 9 months. It is somewhat easier now even though I am doing the same things as I was taught here in the beginning. I am guessing that my problems are still ones of my skipping these steps:

My work flow is complicated as I need a separate sketch plane for every rail in order to get full control of the resulting shape. Doing this allows me to turn off 3-D sketching while drawing the rails making the process a little less frustrating and more tedious at the same time.

1. Create your end sketches.

2. Make a 3-D drawing connecting all the points that will have rails with straight lines. Use the project command to pick very point used. (There are many variations on project. I just type the letter P.) You may need to add points to proper points on your sketch. Make a trial loft with all the straight lines to make sure you picked up all the points.

3. Select one of these straight rails and create a plane at an angle and set the angle.

4. Create a sketch on this plane. (Turn off 3-D drawing)

5. Project the two endpoints into the sketch and draw your rail. (For me this is a spline.)

After each rail is made do a trial loft to make sure it worked. If it does not work delete the sketch and the work plane and repeat. It usually fails because I picked the wrong point to project on accident. Sometimes the 3-D sketch has a bad line.

I hope some of this helps. Others here have more experience and will not have to take such a tedious approach.

[davebYYPCU]

If the article being connected to, is not in the spline (current) sketch, the result is rails are not connected to all profiles.

Another way to say it, if there are no purple articles in the rail sketches, you will not get coincident connections.

Or another way to say it, for lofts, snapping connections to articles outside the current sketch, don't work, produces errors.

For a 3d sketch use Project > Include 3d Geometry, 

Might help....