I remember such a project and I think it was in here - some years back.
Small like a pencil and driven by compressed air.
I remember the picture of the man who made it - a portrait - (because he looked like my borther in law) - a very gently looking man, Black/gray hair, a wonderful smile
I've searched with no Lock - now I'm looking through Darren's postings - because I think that was the name (but there is no picture there today.
Help please !