[Lurkina.n.Learnin]

I saw this yesterday. Might be of interest.

This crazy pen lets you draw real 3D objects in mid-air
http://bgr.com/2017/06/23/3d-printing-pen-amazon-sale/

[roadcat]

This crazy pen lets you draw real 3D objects in mid-air

Those have been around for several years. Bought one for my grandkids to play with a couple years ago. You just use ordinary 3D printer filament in it. Don't know what they go for now, used to be around $50 to $80 each. Probably much cheaper now.