I have a surface model from a vendor of a motor driven linear actuator. The problem I am having is I have to change the configuration of there model when I use it in an assembly to show what it will look as it moves through the cycles. I used Body-Move/Copy and got the model into the configurations I need but then when it is used in an assembly some of the surfaces disapear and I get a ton of mate errors. To solve this I have to go back and open up the model, suppress and unsuppress stuff to make the model look right and then it displays in the assembly correctly, but if I change configurations of the assembly I have to go through this all again. Is there any simple way to convert a surface model to a solid? I can' fill all the gaps if when I am done I can make a solid but if I will just be adding surfaces to the model then I'm not going to bother.