Hi Gary, welcome to MoI and to the forum!

re:
> As an aside, my wireless 3DConnexion Spacemouse does not seem to
> work here, any tips please?

Are you on Mac? For some reason newer 3DConnexion drivers on the Mac stopped working with MoI, I don't know why and they have been unresponsive when asked about it. I should be able to investigate it for MoI v4 but for now if you install an older driver version it should work, see here for which version:
http://moi3d.com/forum/index.php?webtag=MOI&msg=7986.1


> would the attached models print or do they have something nasty like self intersections?

The small one in the attached 3DM file looks ready to print, but the larger one is not ready yet, it does have self intersections because it's actually 2 solids overlapping on top of each other. If you select one of them you'll see these kind of stippled patterns called "z fighting" where the 2 different objects are running right over top of the same surface area:


In order to print property the object should have one unified "skin" and not be made up of separate objects partially pushing through each other like that or overlapping over the same surface area.

Normally if you have 2 objects that cleanly push through each other you can combine them using Construct > Boolean > Union, which will intersect the 2 solids with each other and chop it up into different pieces and discard the pieces that are internal to both solids and glue together the remaining parts to form a new combined solid. This will probably not work in this kind of messy shared surface area case because the 2 surfaces there are not cleanly pushing through each other, the areas with shared surface area will have very shallow intersections which makes for rather complex wandering intersection results and makes it difficult to cleanly divide the objects at the intersections. Intersections need to form clean closed loops in order to divide things into different pieces. So this would probably need to be modeled a bit differently in order to work well, the second piece would need to have its own distinct shape in order to be merged with the other one rather than following along a similar surface area in several spots like it does now.

Hope that makes sense.


> If so, how to make a shape like these 2 on the right? The shape on the left the one (not fro MoI)
> is probably safer but relatively uninteresting.

Either of those should be possible in MoI, the basic technique would be to draw in several cross-section curves with the shape you want, arranged like this:



Then to construct the solid, select those curves and run the Construct > Loft command and set the "Closed" checkbox option that appears in the upper right command options area. That will build a result like this:



The "uninteresting" one could probably be formed by just one profile curve and using Construct > Revolve instead of Loft.

Hope this helps!

- Michael