Ok folks,
thanks to teeth’s contest, which obliged me to work on IKA, I matured some experience in animating mechanics.
My old tutorial is now full with this stuff… doubled in number of pages (and size)
Grab it at
http://www.selleri.org/Blender/tuts/Pistons2.zip
It is a Zipped PDF file, 1M in size
Hope will help you
Stefano
Thanks. A nice read and well illustrated. Clever way to do a quick and dirty spring.
Brilliant!!!
Great re-work on your tutorial, im gonna have alot of fun working with this, great information and insight.
Thank you for the great work Stefano!!! 
Matt
Blend on, and blend well!!!
Very elegant use of armatures ! Great tute !
I guess mine is “obsolete” now 
cheers
EXCELLENT!!!
I came to a stopping point on my starfighter project (WIP thread here) because I wanted to work on the landing gear yet, and had trouble creating pistons and animating them.
I’m about to mail my computer in a day or two (we’re leaving Hawaii for the continent on Tuesday… moving back home to Alabama), but when I get my computer on the other end, and set up to blend again, I’m definitely going to work through this tute… It’s sure to be a great help!
Thanks!
Imp