Hi MMDers.  Now and then I come across a piano roll that will not
track, and there's no immediately apparent reason why.  Sometimes it
turns out that the well in the right-hand spool end is too deep, so
that the distance between the bottom of the well and the flat inside
surface of the spool end is too small for the tracking mechanism to
cope with.  This can happen to a pressed-steel spool end when the roll
is dropped onto its end.

I'm in the throes of making a simple depth gauge (gage in the U.S.?)
to measure this distance on a roll of almost any length, without having
to take the roll to pieces or even to unwind it.  If it works I'll
send a photo to editor@foxtail.com (right Robbie?).  [Right!  Send
to <editor@foxtail.com> ;) ]

In the meantime, does anybody know what that distance is supposed to
be, so I can zero my gauge?

John Phillips in Hobart, Tasmania

 [ The molded ('moulded' in Down Under?) right-hand flange, supplied
 [ by Custom Music Rolls, positions the edge of the paper 0.300 inch
 [ from the flat face of the drive spindle.  -- Robbie