Losing it over Lofts

[hercat]

Hi, I'm trying to create a series of 4 lofts, and not quite sure where I'm going wrong.

The base is a square hole from an extruded cut on a solid. I've made a sketch plane parallel to this square cut, and a sketch on this plane with 4 splines not connected to each other. Each side of the square needs a loft to one of the splines (sort of like a square flower). I've also got guide curves extending from the corners of the square to the the ends of the splines.

I can do the first loft with no problem, but I can't do all four in one loft because I get error messages (loft intersecting itself). If I do one loft, then try to do a second in a separate operation, the sketches and the guide curves have been incorporated into the first one, and can no longer be selected.

I have the following questions
1. Is there some way to fix this problem, or do I need a separate sketch for each loft?
2. If I have to create a separate sketch for each loft, then is there some way to just copy the sections without redrawing them?
3. On a side note, if you make a 2D sketch, then realise you need to draw in 3D, is there some way to change the type without redrawing?

I'm using solidworks 2008, and really appreciate any help you can offer.

 

[gupta9665]

Can you post your part to look at to check what is causing the issue and how to overcome that.

 

[egsindia]

SolidWorks - Self Intersecting Lofts - Causes and Solutions

Hello:

I think you are using different order to select the sections sketches, that sometimes, would lead to self-intersection problems.

Try to select the section segments, ' in the same order' for each of the section. Secondly, ensure that the guide curves, if any, have tangent continuity (no kinks or knots).

If the loft does not get previewed, you would have problems, downstream.

Hope this helps,

Regards
Natarajan R.
EGS India
SolidWorks 2010 SP 4.0