can't select sketch to loft

[yg00516]

I'm building a wing with varying chord length at the tip using this tutorial https://www.youtube.com/watch?v=1l91zRAWbBM (03:00-05:00)

However. I can't select the final airfoil sketch at the tip of the wing when using the loft function, even when I remove the airfoil sketch in the middle.

[erasarnova]

Are you sure that your profile is closed?

Can you share your .ipt file that include sketch?

Sorry i saw .ipt

[erasarnova]

Check your sketch8 is not one profile there are extra lines. trim them.

Check your sketch12 is not closed profile.

Fix them and you can choose.

[Gabriel_Watson · Accepted solution]

Sketch12 profile was not closed:

and also has overlapping splines in a section that creates a different loop... you have to redo it:

I cut off that entire end and the loft works properly with it:

Similar issue with Sketch8:

[yg00516]

Thanks for your help. I'm quite new to inventor and CAD, want to ask howI can delete just that section woth the overlapping lines. 

Thanks

[Gabriel_Watson]

The problem is you had too many spline points in that profile. Zoom to the area that is messy and right-click > Delete the points there until you have the following gap (without any overlapping/extra lines on the remaining loop):

Then drag the lower end-point all the way to the trailing edge to close your loop, and right-click the spline > "Insert Point" as needed to correct its shape: