I am new to this group, but in browsing the articles, I don't see an explanation
of the matter of paper speed vs take-up spool speed.

Were piano rolls originally designed for a constant paper speed (inches per
second) or a constant take-up spool rpm? If the spool rpm is constant, the
paper speed will increase as the paper builds up on the spool, epecially for
long-playing rolls.

Ken

[Non-text portions of this message have been removed]