I have been reading with interest Wayne Stahnke's comments on roll advance
(step rates).  I fully understand that exact step rate is required if he
is to produce (or recreate) the factory master roll through his scanning
process.  The importance of this endeavor cannot be overstated.  While
step rates may be used at a later time after roll scanning, it behooves
us to sort out this problem now.  Our paper rolls are short-lived and we
need to preserve the data without delay.

I have made some measurements on the Ampico rolls in the mid 20's vintage.
In so doing, I have become aware that the exact step rate is a bit
elusive. Is the punch diameter 5/64 or .080?  This exact punch size
plays a very important part in this analysis.

Finally, I would like to know about slippage.  Since the paper feed
through the perforator is not a positive, such as pin feed computer paper,
some slippage will occur.  The type of paper feed scheme will determine
whether the slippage will result in compression on extension.  I still
wonder if the Ampico scheme isn't really 360 steps per inch, but slippage
puts it about 1 percent less -- at Wayne's calculated 356 steps per inch.

I have no strong opinion and would like the hear comments from those
studying this elusive piece of history.

Bob Taylor

 [ Editor's note:
 [
 [ It seems to me that the hole size has no effect on the perforator
 [ advance distance.  Could you explain what you mean, Bob?
 [
 [ The "Ampico Inspector's Test Roll", issued 12/22, bears the notation,
 [ "Chords every 6 inches", and these chords are spaced at precise
 [ intervals along the roll.  I believe that Wayne's optical scanner
 [ is capable of recovering the time-axis data to 1 or 2 thousandths-inch.
 [ I hope he will elaborate on his measurements for us.
 [
 [ Robbie