In this pic, you can see a cam that operates a lever that is part of a wire
cutter. This is an old pic and we now use a roller instead of a cam but the
chain drive is the same. I want to replace this whole drive mechanism with an
air cylinder to move that lever. I roughly figure a 2" bore x 1" stroke will
have enough guts.

http://metalworking.com/Dropbox/_200...ob290-head.JPG

I need the cut timed within one degree of rotation of the same 1" shaft that
drives the chain. I want to be able to easily adjust the timing and have
adjustable dwell. Is there an off-shelf item to do this? I will need two
separate operation switches on the shaft.

I currently use an air limit switch on the other mechanism driven by a cam that
I constructed and we have to replace those switches four times a year due to
failure. Would electrical limit switches and solenoid valves be more reliable?

We are building the third of these machines. The first two are constantly
scheduled for overtime and weekends. The logs show less than 70% up-time due to
all sorts of little issues that we are addressing on the third machine. I'd
like to target 90%+ up-time, that would fall in line with what other machines
log.

(tempest in a teapot---I'm the largest manufacturer of these items in the whole
WORLD)