"Off the shelf" low pressure piston

[vctech]

I am trying to find an "off the self" very low pressure piston for a ID: 3.095" cylinder, I am looking for a piston that can easily slide back and forth similar to the part used in a noise making "gravity tube" like this
(

http://www.amazon.com/Toysmith-TRANSLUCENT-GRAVITY-TUBE/dp/B000YIJWWA)

or a bike pump. A low pressure pump uses air to drive the piston. Preferred piston material is rubber or plastic with an o-ring or some other type of seal. The ideal piston is between (0.25" - 2") in thickness. I am not looking for a entire pneumatic cylinder assembly, I am looking for only the piston. Does anyone know a manufacturer of such a part or similar parts?

 

[alansimpson]

Low friction pneumatic cylinders might do.

http://www.airpot.com/

SMC also do a low friction cylinder range which dosn't use physical seals but relies on air leakage to keep piston moving.

 

[Tmoose]

how much travel/stroke do you need?

 

[vctech]

Roughly 2 feet

 

[hydtools]

Try Bimba:

http://bimba.technicon.com/CC_host/.../product_page.cfm?cc_nvl=((CC,bimba,OL,OL-D))

Ted