Hello MMD,  In response to Bob Taylor's post about take-up
spool slippage, my piano is a home-made Ampico A converted from
a Lexington 88-note foot-pumper back in 1970.  Many of my Jumbo
rolls are recuts of smaller rolls that are combined to fill up
Jumbo spools as much as possible.  I had to spray the backside of
some rolls with Elmer's Slide-All, to make the roll ultra-slippery;
that lubricant actually makes it build up tighter on the take-up
spool from end to end.  I have never even seen a Ampico model B
action, but if the brake system is properly adjusted, there should
be no slippage.

I had to develop a spring loaded brake for all three of my pianos
so the rolls would not slip.  I have an arm that rides in back of
the roll controlling the tension of the spring that is connected to
the brake.  As the roll gets smaller the spring tension diminishes.
For the Jumbo rolls, I added two tiny bellows tubed to left and
right sides of the stack, also spring loaded, that lift the brake
on the loud passages when the paper is pulled harder against the
tracker bar.  It handles the extra bulk of paper of the Jumbo rolls.
Yes, it's tricky to adjust, but when done it works great.

I have many videos on YouTube that play up to a half-hour without
a slip or skip.  At 1.9 gigabytes, for some odd reason, my HG10
Canon separates making two icons that have to be joined together
when converting, leaving a tiny blip in the finished video, but
I can live with it.  Check them out on YouTube.

John Taber
East Hartford, Connecticut

P.S.:  I forgot to mention that I installed a weighted pneumatic,
heavy enough to pull the spring-loaded arm away from the supply roll,
so that the arm will not ride on the back of the roll during reroll,
to guard against damage to the paper.  I also geared down the air
motor for more power to handle the large bulk of paper, and still be
used for foot pumping 88-note rolls.