Thank you very much for your comments Juan, Lance, RAGIII, Guy, Giuseppe, Andrew and GazzaS!
Frank, you are no mere mortal.
I was born on this planet, but sometimes I wish to come from somewhere else to have more usable hands! Two are often really not enough

Can you please let me know what you used to put the slots in the tubing before crimping ?
Andrew, I use a etched saw from
http://www.radubstore.comI don't know, which one I bought. The blad is 0,08mm thin:

Cheers,
Frank