Hi niko, something like Rail revolve can be better for the rounded tip shape.

Or also the "maintain tangent" option for sweep can do a good job of this because it keeps the profiles as slices of parallel planes as they move forward.

The pinching happens when things slide along different length rails, creating some rotation/wobbling type effect. You can maybe see that if you turn on control points for the surfaces.


In order to use "maintain tangent" your profiles have to start out as parallel planes though, currently your front profile does not seem to be planar.


Check out this previous post for a similar example to what you want, using "maintain tangent" on 2-rail sweep:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2908.13


Or sometimes it can be good to do just the tip as a separate surface using revolve or rail revolve and then blend that to the main part.

- Michael

Got it Michael thanks!!
On a seperate note, if I want to offset the edge(curve) of the nose cone along its surface in order to trim with it and create a gap between the cone and the fuselage how would I do that? In other words how do I offset a curve on surface in MOI?
(Trimming with a straight curve in this case is not a good option cause the nose cone has an irregular edge)

Hi niko, if I understand you correctly maybe you could create a tube along the edge you want to offset by drawing a circle and using sweep, then use Construct > Curve > Isect to generate intersection curves between the tube and the surface.

- Michael

Also for "preserve tangent" mode for the 2-rail sweep to work, the profiles need to not only be on parallel planes, but also have a shared tangent direction between them where they touch at least one of the rails.

So you want to have things like horizontal and vertical curve tangents in the spots the profile pieces touch the rails.

- Michael

Hi niko, also some tips if you want to use Network for this kind of thing - make sure the curves are actually touching each other exactly at the point, in your curve setup the different endpoints were not exactly touching.

Also if you have pinching in a Network it can often times help if you add a small circle nearby the tip point.

Since a circle has even proportions, it kind of helps to make the tip shaped better, with corresponding more even proportions between the various pieces as they come together.

For example try the attached version (which is the front part of your curves, just trimmed off) doing a Network without the circle near the end (you'll get the same result as you were getting before), and then with the small circle included.

- Michael