How do I use second 3d guide curve in a loft

[pc-6]

Attached is the file containing the lower half of a aircraft wing tip. Near the leading edge the tip should be fuller than it is with one guide curve set near the thickest part of the wing. I have added another curve but I am unable too select both curves to thicken up the forward part. I think I am going about this the wrong way but am stumped.
Another problem I had when I created the loft was I was unable to have the straight edge of both sketch figures together. It would not loft this way so I added a new plane offset by 1/256". The loft was then sucessfull. for the finished product this small void created by this will not matter, but that doesn't make it proper I know this does not seem correct and do not understand why. A little enlightenment on this would be helpfull.

Oldbelt; if you are out there you are probably the man with the awnsers.

Thanks anyone for their help.

Leif

 

[Oldbelt]

Hi Leif.
You have made the "classical failure", your second guide curve do not start and end at the profile sketches you loft between.
Making the guide spline curve be very carefull to hit the curve with the first point and the last,
when you hit you will get a small star as reply.

 

[pc-6]

Oldbelt,
Thanks for the help. I find it excedingly difficult to sketch in 3d in a case like this where the spline must intersect with a preexisting line.
Do you know why I had to create a additional plane and set the second profile off, instead of having the straight line segments of both sketches on the X axis.

Leif

 

[Oldbelt]

Leif.
Before you start 3D sketch, its importent you have selected a plane to sketch on.
The guide lines from the courser show the elevation over a plane,
when you hit the profilcurves, the elevation guideline shall be zero lenght, non visible.
When editing a 3D curve , select the plane before you click edit at the sketch,
othervise you get some random plane.

The coincident line problem, is somthing with the inner representation of the values
and it is a parameter there is checked, because the SW writer has written a failure message.
It happens now and then one must make that kind of work around to get the wanted result.