Well - my foray into FreeCAD did not end well. I have just deleted the software and all of the work I tried to do with it. I learned a lot in the process. First of all 'Free' isn't always good value. The actual cost was a lot of wasted time as I could not get it to create 3D stl files which were error free. Everything looked OK, but the meshes were bad and the file was full of non-manifold surfaces.

All the help available was just confusing as I do no speak Geek.

I suppose I will just have to bite the bullet and go with Fusion360. At least I have been able to create 3D prints with it.