[ Ref. 170605 MMDigest and
 [ http://www.mmdigest.com/Attachments/17/06/05/170605_170306_AA7512b2.png
 

I'm not sure that the hole positioning is different to the 1/9 inch
spacing.  If the spacing is 0.111 inch, how much variation would be
acceptable?  If we assumed 1/10 of the hole spacing as being a suitable
tolerance, then there could be 0.011 inch of 'offset'.  With the Theme
hole, the hole is actually a double width slot, so a shift in the width
position of the theme hole could be okay too.

From my one and only Artrio roll, it seems to me that the Artrio rolls
have a span of 99 holes, with the treble side having the extra hole
position.  It is clear from my roll that the 98th hole is punched in
the correct position width-wise, but is always punched with an offset
of about half a hole in the length-wise direction.  It would be nice if
anyone can find a drawing/drawings of the design centre values for the
tracker layout.

Can I go out on a limb and suggest the layout was 1/9-inch for the hole
position with a non-accumulating tolerance of +/- 0.01 inch for the
position of each and every hole against the nominal position?

I find the best rolls have been punched with small diameter holes that
appear to be around 0.05 inch.  Making small holes is always more
expensive than larger holes and this is why most rolls are punched with
around 0.06 inch holes.  It doesn't sound like much but there is a
difference in the punch stability.

The Artrio system produces massive amounts of punchings at the treble
side and the stability of the paper must have been a problem.  I know
from the Recordo system, where long punchings are used at position 1
and 98 for the hammer rail, that the paper suffers a bit.  But with the
extra hole used in both Artrio and Ampico B, the closeness of the hole
to the paper edge is a real problem.

It's all guess work from me, but I hope it helps a bit.

Paul Rumpf
Melbourne, Australia.