last night my team was taking inventory and making a list of parts we need to order(yes i know i started a thread over in electronics just like this but this one relates to cylinders). We decided that we need some new pneumatic components. We would like to use cylinders with a 1.5"-3" stroke, the only problem is AM does not sell these(i dont think). I looked on clippard.com and found a great source of them but my question is are these still legal to use? per 2013 rules of course, rules can change i know that
As of last year’s rules, (May or may not be applicable in 2014 - use at your own risk) any COTS (unmodified) pneumatic cylinder rated at above 60 PSI is legal for competition use. So yes, you can use the Clippard cylinders, provided you don’t cut, sand, drill, paint, or otherwise modify them in any way.
Emphasized. Last year’s rules are not this year’s rules.
Bimba is the most common source for cylinders…and they are giving all teams 3 cylinders as a PDV (see TIMS for code)…but for the free ones, I think I’d opt for larger than 3" stroke. If you find you have to buy some cylinders, small ones will be much cheaper than large. We got a 36" (stroke) cylinder one year, because if we ever needed that it would cost a fortune. (We call it “overkill” and almost used it in a net-deploying defensive manner last year).
Last year our team leader bought a couple large cylinders “just in case”. We didn’t use them, but maybe they’ll work in our design this year. 
Will these fit in the sizing box?
We have always used Clippard cylinders. They always have what we need in stock and have been VERY generous to our team.
I didn’t find Bimba in the PDV; are you sure?
Listed under the virtual kit (http://www.usfirst.org/roboticsprograms/frc/kit-of-parts), direct link here (http://www.bimba.com/FIRST-Form-Open/).
Both those links are broken.
At first I thought it was the parentheses that was messing up the links, but I’m not sure. Try copying and pasting if the links are not working…or just use the menus and go to the kit of parts page.
Yeah, I’m not sure what’s different, but the second set works. Thanks very much!