65-88 Note Compatibility

In the world of player piano music rolls, a notable majority were produced on paper 11 1/4" wide. In the period of approximately 1899 through to about 1912, rolls were perforated at a standard 6 holes per horizontal inch, and embraced only 65 of the 88 playing notes of a conventional piano. At about 1912, manufacturers developed methods of automatically tracking rolls over the tracker bar and were then able to perforate rolls at a standard 9 holes per horizontal inch. Out of this significant development emerged the "full-scale" player piano in which all 88 notes were played by the pneumatic mechanism.

Curiously, the majority of music contained within 88 note rolls continued to embrace the same 65 note scale for many years. The major advantage of the 9 per inch standard was the ability to compress additional dynamics data into the margins of these rolls, albeit sacrificing a few rarely used notes at the low bass and high treble ends.

While the paper used for 65 note rolls was 11 1/4" wide, the spool ends employed pins for securing and driving the roll in a spool box. Later 88 note rolls did the opposite, employing dimpled spool ends. As a consequence, the 65 note rolls, excluding their pin ends, were about 3/8" wider than 88 note rolls, but still using paper 11 1/4" wide.

A few player p[ianos in that transitional period of 1912-1913, were constructed with spool boxes capable of accepting both 65 and 88 note rolls. They did this by including an 88 note "cap" to be inserted over the right drive chuck. In such pianos, these removable "caps" are often missing today.

I have some 65 note rolls in my collection, and I have access to a large collection of 65 note rolls. I wanted to scan these rolls as often they contain some interesting, occasionally historically significant music. That meant coming up with a relatively simple method of changing from one roll type to another.

In discussions with Kevin Keymer, he suggested 65 and 88 note threaded chucks. However, the shaft is made of steel, and I do not have suitable tools for working with steel. The chucks though are typically made of brass, much easier to work with, so I chose to work with tiny set screws commonly available at my neighborhood Home Depot.

I could have fabricated new chucks from conventional 1/2" brass rod stock using a hacksaw, grindstone, files and drill press. However, as I had a small stock of spool box parts left over from 35+ years in this delightful avocation, I chose to start with original 88 note chucks.

I had to first remove the chucks from their steel shafts and did so by simply heating them with a propane torch for about 1 minute. The chucks could then be easily knocked off with a common nail set punch, as they were originally a press fit. To compensate for the difference in overall roll width, I chose one long chuck and one short chuck.

The short chuck was aimed at the 65 note rolls, so I ground off its drive tip, drilled it out from its back end, and cut a suitable slot in its new face with a hacksaw. Not pretty or elegant, but effective.

I then drilled and tapped a #6-32 hole in both chucks to accept 6-32 set screws.

Within the longer chuck aimed at 88 note rolls, I drilled it out internally deeper than necessary, then inserted a 1/8" wood dowel to set the spacing correctly. Took a bit of cutting with an X-Acto knife to get it right.

In operation, I set up my roll transport first in 65 note mode, then adjusted the wood plug for the 88 note chuck. The objective is to have the roll and the CIS centered to one another, regardless if 65 or 88 note roll. Takes a bit of fiddling with the tiny set screws, so I choose to set myself up in batch mode, scanning a batch of 65 note rolls, then restoring the roll transport to 88 note mode.

The left chuck is not a factor. A conventional "dimpled" 88 note left chuck can accept 65n, 58n and 88 note rolls. As it is spring loaded, it automatically adjusts itself for the 3 roll types. The following pics say it all.


Overview of my roll transport during a scan of a 65 note roll.


These are the 2 chucks - 88 note and 65 note, both with 6-32 set screws
which may be tightened with a conventional allen key.


Note the extended spring loading of this left chuck with a 65 note roll loaded.


Note the reduced extension of the spring loading of the left chuck with an 88 note roll loaded.


View of the right chuck with a 65 note roll loaded.


View of the right chuck with an 88 note roll loaded.


View of a 65 note roll centered under the CIS.


View of an 88 note roll centered under the CIS.

Software

The MK3 software is ordinarily aimed at rolls perforated at 9 holes per horizontal inch. Kevin Keymer kindly modified the CIS to SCN and the SCN to MID utilities to deal with rolls perforated at 6 holes per horizontal inch. This development is the subject of another document yet to be published. Stay tuned......


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