I can´t make loft, error with G1, with rails

[tomas.mlcak]

Hi,

i use loft in Inventor on school previously very much. Now, i modeling 3D desing sketch of mini communal car and rear tail of airplanes. Fusion shows some warning and error message…

First error is on car: The guide is not G1 between first and last sections.

Second is some problem with much sketch. When I select sketch 2, 3 (profile 1, 2) and rails from 3Dsketch, on next picture, is ok.

When i select fitst sketch, second sketrh, third, fourth, fifth sketch (profile 1-5), without rail is ok.

Add rails is problem, because I can selecting only part of line, no complete line from first sketch do last sketch.

Can You help me?

Thank you

[innovatenate]

Can you share the Fusion Design?

It looks like the guide rails may not be tangent continuous, but it will be much easier to investigate with the design in hand.

If there are any questions, please let me know.

Thanks,

[tomas.mlcak]

There is models:

http://a360.co/2aIt5K7

http://a360.co/2fr6bg6

You don´t see on errors on sketch because I delete some sketch, when you need solve.

[innovatenate]

If you clean up the profiles so that there are not multiple overlapping profiles (see constructions lines), that is one thing that will help.

I then recreated the rails from scratch using a spline (with 3D sketch enabled in the sketch pallette). This allows me to quickly snap to the correct point on each of the profiles and generate a smooth rail. 

At each profile, there is a fit point for the 3D spline that is coincident with a point on the profile.

After setting the loft up this way, I can easily create a loft with or without Guide Rails. See the attached file as a sample

.

I hope that helps. Let me know if you have any other questions. 

Thanks.

[tomas.mlcak]

Use constrution line is better, I thought so.

Why spline? I need straight line between sketch 2 and 3, sketch 3 and 4, sketch 4 and 5. And spline is curve. Without spline rails is loft better......

On picture, I have intersection curve from two elipse. Loft donť accept this line as rail. I want use spline and spline is out of trajectory of intersection curve.....

And I have next question. In the 3D sketch, How can I do  line tangent to next line (curve ellipse) in point?

[innovatenate]

If you would like a straight lines between the profiles, try lofting between each profile separately. You do not need to create guide rails in this case. You can later use the Modify > Combine or Modify > Stitch command to join the bodies, converting many bodies into a single body. See the below Screencast for reference.

Splines are tangent continuous (G1), which is what the original error message is about. I used a spline because it is very easy to generate clean sketches. I will show how to edit 3D spline handles in the next post.

[innovatenate]

Modifying a 3D spline can be kind of tricky. You need to use the Move command to move the endpoints of the tangent or curvature handle. In 2D spline, you can apply dimensions to the tangent or curvature handles. See the below screencasts.

3D Splines vs 2D Splines (In sketch plane)

I hope that helps. 

Thanks,

[Anonymous]

I changed the corner of my spline with my line to be tangent and it worked for me, thank you