well, I only took basic Solidwork class. The advanced class, which will cover 3D sketch, is in June. Until then, I don't know how to work with 3D sketch. I can probably try but i will probably be just a mess. Thanks for the quick solution.
Its easy. Try. Click spline tool and click on ends helices. After second click press ESC key. Now spline look as line. Click it and one helix wit CTRL key and add tangent constrain. The same with second helix.
Attach screenshot please.