How can I reduce friction in my sliding elevator design?

[EpiGen]

I am a third year chemical engineering student and don't have much experience in the mechanical stream so I was hoping someone here could help me.

At the moment I have an apparatus that consists of a sheet of metal with four syringes sticking through (metal sheet is horizontal, syringes are vertical with plungers sticking up.) I need to be able to push these syringes down at the same speed (each will have the same substance inside.) I am thinking of a way to make an elevator that I can put weights on top of (to increase/decrease speed) - it would essentially be a second sheet of metal that rests horizontally on top of the plungers with metal rods on each side that it can slide on (there will be holes on each side of the sliding plate.) I was trying to think of a way that I could have two metal rods on each side of the plate and the metal would slide down and remain level. However, when I make the whole into the sheet and test the sliding down the metal rod it happens in jerks because of friction, and I need it to move smoothly.

(Hope what I wrote above makes sense)

So, overall, I'm trying to think of a way to reduce this friction between the sliding plate and the two vertical rods it slides on. Or if there's a better way to do this - I'm all ears!

Another thing, does anyone know of a lubricant that works well between two metal surfaces?

 

[pantaz]

What you are describing is essentially a "die plate" as used in a hydraulic press for stamping/punching/forming sheet metal.
Wiki has a photo of one, http://en.wikipedia.org/wiki/Die_(manufacturing ).
The catalog (PDF) at the following website shows the various components, such as bushings and linear bearings: http://www.lempco.com/products.html

Probably would not be too difficult to use commonly available bushings or bearings to replicate the function of a die plate for your needs.