My only experience with auto tracking mechanisms has been with my
Standard action pumper, which has the 4 hole auto mechanism.  All I
can say is, it works like a charm.  I can play rolls with shredded left
and right margins, and it tracks them perfectly.  I've never done any
adjustments on the mechanism; it's set the way it was when I purchased
it 3.5 years ago, fully-restored.

I was surprised that some folks have commented that it can tear rolls --
I can see that with a mechanism that has "ears", but how four holes on a
tracker bar, which don't operate during rewind, can tear a roll is beyond
me!

Jim Canavan
cybrflash@aol.com