Create solid between 3d entities

[eskoansami]

Hello,

Im very new to Autocad and use it mainly to prep DWGs for Vectorworks. I have attached a file containing two splines. They are not planar objects so I understand I can not loft them together. What is the easiest way to create solid between these entities? I have to do this very often, and approx. 100 times per project, so I would like to avoid creating 2d entities by hand and then lofting them together.

Thanks for any help!

[CGBenner]

@eskoansami 

Welcome to the forum!  Thank you for your question and for sharing your dataset for our experts to look at.  Good luck!

[leeminardi · Accepted solution]

1. Eplode the objects from blocks to splines.
2. use loft to create a surface between the two splines
3. create a cylindrical surface (red) to cap the ends from two arcs.
   
4. Use surfsculpt to create a solid from the surfaces that define a watertight volume.
   
5. It would help if you could also import geometry that defines the end shape off the tube.  It looks like the splines were frmed from the intersection of cylinders. I guestimated the radius and location for the extruded arcs.