FYI, there's a good tutorial on this forum for using the eMachineshop 2D CAD program:
https://www.hobby-machinist.com/threads/cnc-from-sketch-to-part-the-way-i-do-it.19633/
While it's only a 2D program (last I looked), the thread is easy to follow and I caught on fast.
I'm getting the impression your friend is worried about someone stealing his ideal, hence not wanting to give up much info.
If he's thinking about trying to patent it, he might want to research it some.
I had similar thought on a couple project I have in mind. What I found is that patents are RELATIVELY inexpensive to obtain, they are very expensive to enforce. Plan on hiring a patent lawyer just for the application.
IMHO, open sourcing it is a much better option and applying for a copyright, much cheaper way to go.
While a copyright won't prevent other businesses from producing and selling his idea, they can't call it the copyright name.
If it's something a business wouldn't be interested in producing, anyone with the capability to reproduce it for themselves can and probably will depending on price and ease of construction.