On Wed, 24 Mar 2004 11:48:26 -0800, Koz
vaguely proposed a theory
.......and in reply I say!:
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If you can avoid anything that turns the rollers on the chain, you may
get a little better life in a dirty environment. Even though the
bushings are hardened (and sometimes the rollers, sometimes neither in
really crappy chain), you have a steel against steel wear point.


Yeah. I was thinking about this. Chain wear is the biggest problem,
not some bit of plastic. But as you say, a static piece of plastic
will turn the rollers.

We use what we call a "follower wheel". Basically, it's a UHMW wheel
with a bump that sticks out for some guiding between the chain sidebars.
The bump doesn't stick out quite to the point of touching the rollers.
The sidebars of the chain sit on the shoulders of the UHMW follower
wheel. Sidebars can wear down quite a lot and still not cause sprocket
engagement problems whereas if the rollers wear even a little, you can
start having problems.


I'm not sure of the speed of the chain or the overall tension so cannot
say if UHMW would be adequate for your application. A spring system
will probably be enough to apply the tension you need.

Fairly slow. It comes of a 3" sprocket on a 500 RPM PTO on a tractor.


Oh yea...go as large as possible on any tensioner so that the chain
doesn't have to bang it's way around a small diameter bend.

Yes. I thought of this when I considered a ball bearing (now discarded
as an idea). If the tensioner does not use a sprocket, too small wheel
will cause a constant chattering.
************************************************** ** sorry

..........no I'm not!
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