Printing one off circuit boards at home
 

I watch a lot of 3d printing stuff as I do a lot of 3d printing. Youtube suggested this one and I thought it was pretty cool. Not my cup of tea as I don't work with electronics much, but I'm sure some of you will like it.

https://www.youtube.com/watch?v=8u4izLA-SCo

That's an interesting mixture of CNC and 2.5D printing in a single device. But.... In addition to his lists of contraindications, I'd add lots of fiddly hand work, with the swapping out heads, trimming and rivets.

Printing conductive traces inside an arbitrary 3D shape would be more interesting.

I had very similar thoughts. They did a nice job of making a machine that does it all... but that does mean its not super great at one thing. Also, there are quite a few steps to actually get the board made. Still, if I was developing lots of boards I could see this being quite useful as I'm sure you get used to running through the process of what all needs to be done.